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 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



 NAME
      screen - screen manager with VT100/ANSI terminal emulation



 SYNOPSIS
      screen [ -options ] [ cmd [ args ] ]
      screen -r [[pid.]tty[.host]]
      screen -r sessionowner/[[pid.]tty[.host]]



 DESCRIPTION
      Screen is a full-screen window manager that multiplexes a physical
      terminal between several processes (typically interactive shells).
      Each virtual terminal provides the functions of a DEC VT100 terminal
      and, in addition, several control functions from the ISO 6429 (ECMA
      48, ANSI X3.64) and ISO 2022 standards (e.g. insert/delete line and
      support for multiple character sets).  There is a scrollback history
      buffer for each virtual terminal and a copy-and-paste mechanism that
      allows moving text regions between windows.

      When screen is called, it creates a single window with a shell in it
      (or the specified command) and then gets out of your way so that you
      can use the program as you normally would.  Then, at any time, you can
      create new (full-screen) windows with other programs in them
      (including more shells), kill existing windows, view a list of
      windows, turn output logging on and off, copy-and-paste text between
      windows, view the scrollback history, switch between windows in
      whatever manner you wish, etc. All windows run their programs
      completely independent of each other. Programs continue to run when
      their window is currently not visible and even when the whole screen
      session is detached from the user's terminal.  When a program
      terminates, screen (per default) kills the window that contained it.
      If this window was in the foreground, the display switches to the
      previous window; if none are left, screen exits. Shells usually
      distinguish between running as login-shell or sub-shell.  Screen runs
      them as sub-shells, unless told otherwise (See "shell" .screenrc
      command).

      Everything you type is sent to the program running in the current
      window.  The only exception to this is the one keystroke that is used
      to initiate a command to the window manager.  By default, each command
      begins with a control-a (abbreviated C-a from now on), and is followed
      by one other keystroke.  The command character and all the key
      bindings can be fully customized to be anything you like, though they
      are always two characters in length.

      Screen does not understand the prefix "C-" to mean control, although
      this notation is used in this manual for readability. Please use the
      caret notation ("^A" instead of "C-a") as arguments to e.g. the escape



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 SCREEN(1)                                                         SCREEN(1)
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      command or the -e option.  Screen will also print out control
      characters in caret notation.

      The standard way to create a new window is to type "C-a c".  This
      creates a new window running a shell and switches to that window
      immediately, regardless of the state of the process running in the
      current window.  Similarly, you can create a new window with a custom
      command in it by first binding the command to a keystroke (in your
      .screenrc file or at the "C-a :" command line) and then using it just
      like the "C-a c" command.  In addition, new windows can be created by
      running a command like:

           screen emacs prog.c

      from a shell prompt within a previously created window.  This will not
      run another copy of screen, but will instead supply the command name
      and its arguments to the window manager (specified in the $STY
      environment variable) who will use it to create the new window.  The
      above example would start the emacs editor (editing prog.c) and switch
      to its window. - Note that you cannot transport environment variables
      from the invoking shell to the application (emacs in this case),
      because it is forked from the parent screen process, not from the
      invoking shell.

      If "/etc/utmp" is writable by screen, an appropriate record will be
      written to this file for each window, and removed when the window is
      terminated.  This is useful for working with "talk", "script",
      "shutdown", "rsend", "sccs" and other similar programs that use the
      utmp file to determine who you are. As long as screen is active on
      your terminal, the terminal's own record is removed from the utmp
      file. See also "C-a L".



 GETTING STARTED
      Before you begin to use screen you'll need to make sure you have
      correctly selected your terminal type, just as you would for any other
      termcap/terminfo program.  (You can do this by using tset for
      example.)

      If you're impatient and want to get started without doing a lot more
      reading, you should remember this one command:  "C-a ?".  Typing these
      two characters will display a list of the available screen commands
      and their bindings. Each keystroke is discussed in the section
      "DEFAULT KEY BINDINGS". The manual section "CUSTOMIZATION" deals with
      the contents of your .screenrc.

      If your terminal is a "true" auto-margin terminal (it doesn't allow
      the last position on the screen to be updated without scrolling the
      screen) consider using a version of your terminal's termcap that has
      automatic margins turned off. This will ensure an accurate and optimal



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 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      update of the screen in all circumstances. Most terminals nowadays
      have "magic" margins (automatic margins plus usable last column). This
      is the VT100 style type and perfectly suited for screen.  If all
      you've got is a "true" auto-margin terminal screen will be content to
      use it, but updating a character put into the last position on the
      screen may not be possible until the screen scrolls or the character
      is moved into a safe position in some other way. This delay can be
      shortened by using a terminal with insert-character capability.



 COMMAND-LINE OPTIONS
      Screen has the following command-line options:

      -a   include all capabilities (with some minor exceptions) in each
           window's termcap, even if screen must redraw parts of the display
           in order to implement a function.

      -A   Adapt the sizes of all windows to the size of the current
           terminal.  By default, screen tries to restore its old window
           sizes when attaching to resizable terminals (those with "WS" in
           its description, e.g. suncmd or some xterm).

      -c file
           override the default configuration file from "$HOME/.screenrc" to
           file.

      -d|-D [pid.tty.host]
           does not start screen, but detaches the elsewhere running screen
           session. It has the same effect as typing "C-a d" from screen's
           controlling terminal. -D is the equivalent to the power detach
           key.  If no session can be detached, this option is ignored. In
           combination with the -r/-R option more powerful effects can be
           achieved:

      -d -r   Reattach a session and if necessary detach it first.

      -d -R   Reattach a session and if necessary detach or even create it
              first.

      -d -RR  Reattach a session and if necessary detach or create it. Use
              the first session if more than one session is available.

      -D -r   Reattach a session. If necessary detach and logout remotely
              first.

      -D -R   Attach here and now. In detail this means: If a session is
              running, then reattach. If necessary detach and logout
              remotely first.  If it was not running create it and notify
              the user. This is the author's favorite.




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                                  Jul 2017



      -D -RR  Attach here and now. Whatever that means, just do it.

           Note: It is always a good idea to check the status of your
           sessions by means of "screen -list".

      -e xy
           specifies the command character to be x and the character
           generating a literal command character to y (when typed after the
           command character).  The default is "C-a" and `a', which can be
           specified as "-e^Aa".  When creating a screen session, this
           option sets the default command character. In a multiuser session
           all users added will start off with this command character. But
           when attaching to an already running session, this option changes
           only the command character of the attaching user.  This option is
           equivalent to either the commands "defescape" or "escape"
           respectively.

      -f, -fn, and -fa
           turns flow-control on, off, or "automatic switching mode".  This
           can also be defined through the "defflow" .screenrc command.

      -h num
           Specifies the history scrollback buffer to be num lines high.

      -i   will cause the interrupt key (usually C-c) to interrupt the
           display immediately when flow-control is on.  See the "defflow"
           .screenrc command for details.  The use of this option is
           discouraged.

      -l and -ln
           turns login mode on or off (for /etc/utmp updating).  This can
           also be defined through the "deflogin" .screenrc command.

      -ls [match]
      -list [match]
           does not start screen, but prints a list of pid.tty.host strings
           identifying your screen sessions.  Sessions marked `detached' can
           be resumed with "screen -r". Those marked `attached' are running
           and have a controlling terminal. If the session runs in multiuser
           mode, it is marked `multi'. Sessions marked as `unreachable'
           either live on a different host or are `dead'.  An unreachable
           session is considered dead, when its name matches either the name
           of the local host, or the specified parameter, if any.  See the
           -r flag for a description how to construct matches.  Sessions
           marked as `dead' should be thoroughly checked and removed. Ask
           your system administrator if you are not sure. Remove sessions
           with the -wipe option.

      -L   tells screen to turn on automatic output logging for the windows.





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 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      -Logfile file
           By default logfile name is "screenlog.0". You can set new logfile
           name with the "-Logfile" option.

      -m   causes screen to ignore the $STY environment variable. With
           "screen -m" creation of a new session is enforced, regardless
           whether screen is called from within another screen session or
           not. This flag has a special meaning in connection with the `-d'
           option:

      -d -m   Start screen in "detached" mode. This creates a new session
              but doesn't attach to it. This is useful for system startup
              scripts.

      -D -m   This also starts screen in "detached" mode, but doesn't fork a
              new process. The command exits if the session terminates.

      -O   selects a more optimal output mode for your terminal rather than
           true VT100 emulation (only affects auto-margin terminals without
           `LP').  This can also be set in your .screenrc by specifying `OP'
           in a "termcap" command.

      -p number_or_name|-|=|+
           Preselect a window. This is useful when you want to reattach to a
           specific window or you want to send a command via the "-X" option
           to a specific window. As with screen's select command, "-"
           selects the blank window. As a special case for reattach, "="
           brings up the windowlist on the blank window, while a "+" will
           create a new window. The command will not be executed if the
           specified window could not be found.

      -q   Suppress printing of error messages. In combination with "-ls"
           the exit value is as follows: 9 indicates a directory without
           sessions. 10 indicates a directory with running but not
           attachable sessions. 11 (or more) indicates 1 (or more) usable
           sessions.  In combination with "-r" the exit value is as follows:
           10 indicates that there is no session to resume. 12 (or more)
           indicates that there are 2 (or more) sessions to resume and you
           should specify which one to choose. In all other cases "-q" has
           no effect.

      -Q   Some commands now can be queried from a remote session using this
           flag, e.g. "screen -Q windows". The commands will send the
           response to the stdout of the querying process. If there was an
           error in the command, then the querying process will exit with a
           non-zero status.

           The commands that can be queried now are:
            echo
            info
            lastmsg



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                                  Jul 2017



            number
            select
            time
            title
            windows

      -r [pid.tty.host]
      -r sessionowner/[pid.tty.host]
           resumes a detached screen session.  No other options (except
           combinations with -d/-D) may be specified, though an optional
           prefix of [pid.]tty.host may be needed to distinguish between
           multiple detached screen sessions.  The second form is used to
           connect to another user's screen session which runs in multiuser
           mode. This indicates that screen should look for sessions in
           another user's directory. This requires setuid-root.

      -R   resumes screen only when it's unambiguous which one to attach,
           usually when only one screen is detached. Otherwise lists
           available sessions.  -RR attempts to resume the first detached
           screen session it finds.  If successful, all other command-line
           options are ignored.  If no detached session exists, starts a new
           session using the specified options, just as if -R had not been
           specified. The option is set by default if screen is run as a
           login-shell (actually screen uses "-xRR" in that case).  For
           combinations with the -d/-D option see there.

      -s program
           sets the default shell to the program specified, instead of the
           value in the environment variable $SHELL (or "/bin/sh" if not
           defined).  This can also be defined through the "shell" .screenrc
           command.  See also there.

      -S sessionname
           When creating a new session, this option can be used to specify a
           meaningful name for the session. This name identifies the session
           for "screen -list" and "screen -r" actions. It substitutes the
           default [tty.host] suffix.

      -t name
           sets the title (a.k.a.) for the default shell or specified
           program.  See also the "shelltitle" .screenrc command.

      -T term
           Set the $TERM environment variable using the specified term as
           opposed to the default setting of screen.

      -U   Run screen in UTF-8 mode. This option tells screen that your
           terminal sends and understands UTF-8 encoded characters. It also
           sets the default encoding for new windows to `utf8'.





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 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      -v   Print version number.

      -wipe [match]
           does the same as "screen -ls", but removes destroyed sessions
           instead of marking them as `dead'.  An unreachable session is
           considered dead, when its name matches either the name of the
           local host, or the explicitly given parameter, if any.  See the
           -r flag for a description how to construct matches.

      -x   Attach to a not detached screen session. (Multi display mode).
           Screen refuses to attach from within itself. But when cascading
           multiple screens, loops are not detected; take care.

      -X   Send the specified command to a running screen session. You may
           use the -S option to specify the screen session if you have
           several screen sessions running. You can use the -d or -r option
           to tell screen to look only for attached or detached screen
           sessions. Note that this command doesn't work if the session is
           password protected.


      -4   Resolve hostnames only to IPv4 addresses.

      -6   Resolve hostnames only to IPv6 addresses.

 DEFAULT KEY BINDINGS
      As mentioned, each screen command consists of a "C-a" followed by one
      other character.  For your convenience, all commands that are bound to
      lower-case letters are also bound to their control character
      counterparts (with the exception of "C-a a"; see below), thus, "C-a c"
      as well as "C-a C-c" can be used to create a window. See section
      "CUSTOMIZATION" for a description of the command.

      The following table shows the default key bindings. The trailiing
      commas in boxes with multiple keystroke entries are separators, not
      part of the bindings.  allbox tab(;); lb l l.  C-a ';(select);T{
      Prompt for a window name or number to switch to.  T} C-a
      [dq];(windowlist -b);T{ Present a list of all windows for selection.
      T} C-a digit;(select 0-9);T{ Switch to window number 0 - 9 T} C-a
      -;(select -);T{ Switch to window number 0 - 9, or to the blank window.
      T} C-a tab;(focus);T{ Switch the input focus to the next region.  See
      also split, remove, only.  T} C-a C-a;(other);T{ Toggle to the window
      displayed previously.  Note that this binding defaults to the command
      character typed twice, unless overridden.  For instance, if you use
      the option "-e]x", this command becomes "]]".  T} C-a a  ;(meta);T{
      Send the command character (C-a) to window. See escape command.  T}
      C-a A;(title);T{ Allow the user to enter a name for the current
      window.  T} T{ C-a b,
      C-a C-b T};(break);T{ Send a break to window.  T} C-a B;(pow_break);T{
      Reopen the terminal line and send a break.  T} T{ C-a c,
      C-a C-c T};(screen);T{ Create a new window with a shell and switch to



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                                  Jul 2017



      that window.  T} C-a C;(clear);T{ Clear the screen.  T} T{ C-a d,
      C-a C-d T};(detach);T{ Detach screen from this terminal.  T} C-a D
      D;(pow_detach);T{ Detach and logout.  T} T{ C-a f,
      C-a C-f T};(flow);T{ Toggle flow on, off or auto.  T} C-a F;(fit);T{
      Resize the window to the current region size.  T} C-a C-g;(vbell);T{
      Toggles screen's visual bell mode.  T} C-a h;(hardcopy);T{ Write a
      hardcopy of the current window to the file "hardcopy.n".  T} C-a
      H;(log);T{ Begins/ends logging of the current window to the file
      "screenlog.n".  T} T{ C-a i,
      C-a C-i T};(info);T{ Show info about this window.  T} T{ C-a k,
      C-a C-k T};(kill);T{ Destroy current window.  T} T{ C-a l,
      C-a C-l T};(redisplay);T{ Fully refresh current window.  T} C-a
      L;(login);T{ Toggle this windows login slot. Available only if screen
      is configured to update the utmp database.  T{ C-a m,
      C-a C-m T};(lastmsg);T{ Repeat the last message displayed in the
      message line.  T} C-a M;(monitor);T{ Toggles monitoring of the current
      window.  T} T{ C-a space,
      C-a n,
      C-a C-n T};(next);T{ Switch to the next window.  T} C-a N;(number);T{
      Show the number (and title) of the current window.  T} T{ C-a
      backspace,
      C-a C-h,
      C-a p,
      C-a C-p T};(prev);T{ Switch to the previous window (opposite of C-a
      n).  T} T{ C-a q,
      C-a C-q T};(xon);T{ Send a control-q to the current window.  T} C-a
      Q;(only);T{ Delete all regions but the current one.  See also split,
      remove, focus.  T} T{ C-a r,
      C-a C-r T};(wrap);T{ Toggle the current window's line-wrap setting
      (turn the current window's automatic margins on and off).  T} T{ C-a
      s,
      C-a C-s; T};(xoff);T{ Send a control-s to the current window.  T} C-a
      S;(split);T{ Split the current region horizontally into two new ones.
      See also only, remove, focus.  T} T{ C-a t,
      C-a C-t T};(time);T{ Show system information.  T} C-a v;(version);T{
      Display the version and compilation date.  T} C-a C-v;(digraph);T{
      Enter digraph.  T} T{ C-a w,
      C-a C-w T};(windows);T{ Show a list of window.  T} C-a W;(width);T{
      Toggle 80/132 columns.  T} C-a x or C-a C-x;(lockscreen);T{ Lock this
      terminal.  T} C-a X ;(remove);T{ Kill the current region.  See also
      split, only, focus.  T} T{ C-a z,
      C-a C-z T};(suspend);T{ Suspend screen.  Your system must support
      BSD-style job-control.  T} C-a Z;(reset);T{ Reset the virtual terminal
      to its "power-on" values.  T} C-a .;(dumptermcap);T{ Write out a
      ".termcap" file.  T} C-a ?;(help);T{ Show key bindings.  T} C-a
      \;(quit);T{ Kill all windows and terminate screen.  T} C-a
      :;(colon);T{ Enter command line mode.  T} T{ C-a [,
      C-a C-[,
      C-a esc T};(copy);T{ Enter copy/scrollback mode.  T} T{ C-a C-],
      C-a ] T};(paste .);T{ Write the contents of the paste buffer to the
      stdin queue of the current window. T} T{ C-a {,



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      C-a } T};(history);T{ Copy and paste a previous (command) line.  T}
      C-a >;(writebuf);T{ Write paste buffer to a file.  T} C-a
      <;(readbuf);T{ Reads the screen-exchange file into the paste buffer.
      T} C-a =;(removebuf);T{ Removes the file used by C-a < and C-a >.  T}
      C-a ,;(license);T{ Shows where screen comes from, where it went to and
      why you can use it.  T} C-a _;(silence);T{ Start/stop monitoring the
      current window for inactivity.  T} C-a |;(split -v);T{ Split the
      current region vertically into two new ones.  T} C-a *;(displays);T{
      Show a listing of all currently attached displays.  T}


 CUSTOMIZATION
      The "socket directory" defaults either to $HOME/.screen or simply to
      /tmp/screens or preferably to /usr/local/screens chosen at compile-
      time. If screen is installed setuid-root, then the administrator
      should compile screen with an adequate (not NFS mounted) socket
      directory. If screen is not running setuid-root, the user can specify
      any mode 700 directory in the environment variable $SCREENDIR.

      When screen is invoked, it executes initialization commands from the
      files "/usr/local/etc/screenrc" and ".screenrc" in the user's home
      directory. These are the "programmer's defaults" that can be
      overridden in the following ways: for the global screenrc file screen
      searches for the environment variable $SYSSCREENRC (this override
      feature may be disabled at compile-time). The user specific screenrc
      file is searched in $SCREENRC, then $HOME/.screenrc.  The command line
      option -c takes precedence over the above user screenrc files.

      Commands in these files are used to set options, bind functions to
      keys, and to automatically establish one or more windows at the
      beginning of your screen session.  Commands are listed one per line,
      with empty lines being ignored.  A command's arguments are separated
      by tabs or spaces, and may be surrounded by single or double quotes.
      A `#' turns the rest of the line into a comment, except in quotes.
      Unintelligible lines are warned about and ignored.  Commands may
      contain references to environment variables. The syntax is the shell-
      like "$VAR " or "${VAR}". Note that this causes incompatibility with
      previous screen versions, as now the '$'-character has to be protected
      with '\' if no variable substitution shall be performed. A string in
      single-quotes is also protected from variable substitution.

      Two configuration files are shipped as examples with your screen
      distribution: "etc/screenrc" and "etc/etcscreenrc". They contain a
      number of useful examples for various commands.

      Customization can also be done 'on-line'. To enter the command mode
      type `C-a :'. Note that commands starting with "def" change default
      values, while others change current settings.

      The following commands are available:




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      acladd usernames [crypted-pw]

      addacl usernames

      Enable users to fully access this screen session. Usernames can be one
      user or a comma separated list of users. This command enables to
      attach to the screen session and performs the equivalent of `aclchg
      usernames +rwx "#?"'.  executed. To add a user with restricted access,
      use the `aclchg' command below.  If an optional second parameter is
      supplied, it should be a crypted password for the named user(s).
      `Addacl' is a synonym to `acladd'.  Multi user mode only.

      aclchg usernames permbits list

      chacl usernames permbits list

      Change permissions for a comma separated list of users. Permission
      bits are represented as `r', `w' and `x'. Prefixing `+' grants the
      permission, `-' removes it. The third parameter is a comma separated
      list of commands and/or windows (specified either by number or title).
      The special list `#' refers to all windows, `?' to all commands. if
      usernames consists of a single `*', all known users are affected.

      A command can be executed when the user has the `x' bit for it.  The
      user can type input to a window when he has its `w' bit set and no
      other user obtains a writelock for this window. Other bits are
      currently ignored. To withdraw the writelock from another user in
      window 2: `aclchg username -w+w 2'.  To allow read-only access to the
      session: `aclchg username -w "#"'. As soon as a user's name is known
      to screen he can attach to the session and (per default) has full
      permissions for all command and windows. Execution permission for the
      acl commands, `at' and others should also be removed or the user may
      be able to regain write permission.  Rights of the special username
      nobody cannot be changed (see the "su" command).  `Chacl' is a synonym
      to `aclchg'.  Multi user mode only.

      acldel username

      Remove a user from screen's access control list. If currently
      attached, all the user's displays are detached from the session. He
      cannot attach again.  Multi user mode only.

      aclgrp username [groupname]

      Creates groups of users that share common access rights. The name of
      the group is the username of the group leader. Each member of the
      group inherits the permissions that are granted to the group leader.
      That means, if a user fails an access check, another check is made for
      the group leader.  A user is removed from all groups the special value
      "none" is used for groupname.  If the second parameter is omitted all
      groups the user is in are listed.



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                                  Jul 2017



      aclumask [[ users ] +bits | [ users ] -bits... ]

      umask [[ users ] +bits | [ users ] -bits... ]

      This specifies the access other users have to windows that will be
      created by the caller of the command.  Users may be no, one or a comma
      separated list of known usernames. If no users are specified, a list
      of all currently known users is assumed. Bits is any combination of
      access control bits allowed defined with the "aclchg" command. The
      special username "?" predefines the access that not yet known users
      will be granted to any window initially.  The special username "??"
      predefines the access that not yet known users are granted to any
      command. Rights of the special username nobody cannot be changed (see
      the "su" command).  `Umask' is a synonym to `aclumask'.

      activity message

      When any activity occurs in a background window that is being
      monitored, screen displays a notification in the message line.  The
      notification message can be re-defined by means of the "activity"
      command.  Each occurrence of `%' in message is replaced by the number
      of the window in which activity has occurred, and each occurrence of
      `^G' is replaced by the definition for bell in your termcap (usually
      an audible bell).  The default message is

                  'Activity in window %n'

      Note that monitoring is off for all windows by default, but can be
      altered by use of the "monitor" command (C-a M).

      allpartial on|off

      If set to on, only the current cursor line is refreshed on window
      change.  This affects all windows and is useful for slow terminal
      lines. The previous setting of full/partial refresh for each window is
      restored with "allpartial off".  This is a global flag that
      immediately takes effect on all windows overriding the "partial"
      settings. It does not change the default redraw behavior of newly
      created windows.

      altscreen on|off

      If set to on, "alternate screen" support is enabled in virtual
      terminals, just like in xterm.  Initial setting is `off'.

      at [identifier][#|*|%] command [args

      Execute a command at other displays or windows as if it had been
      entered there.  "At" changes the context (the `current window' or
      `current display' setting) of the command. If the first parameter
      describes a non-unique context, the command will be executed multiple



                                   - 11 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      times. If the first parameter is of the form `identifier*' then
      identifier is matched against user names.  The command is executed
      once for each display of the selected user(s). If the first parameter
      is of the form `identifier%' identifier is matched against displays.
      Displays are named after the ttys they attach. The prefix `/dev/' or
      `/dev/tty' may be omitted from the identifier.  If identifier has a
      `#' or nothing appended it is matched against window numbers and
      titles. Omitting an identifier in front of the `#', `*' or `%'-
      character selects all users, displays or windows because a prefix-
      match is performed. Note that on the affected display(s) a short
      message will describe what happened. Permission is checked for
      initiator of the "at" command, not for the owners of the affected
      display(s).  Note that the '#' character works as a comment introducer
      when it is preceded by whitespace. This can be escaped by prefixing a
      '\'. Permission is checked for the initiator of the "at" command, not
      for the owners of the affected display(s).

      Caveat: When matching against windows, the command is executed at
      least once per window. Commands that change the internal arrangement
      of windows (like "other") may be called again. In shared windows the
      command will be repeated for each attached display. Beware, when
      issuing toggle commands like "login"!  Some commands (e.g. "process")
      require that a display is associated with the target windows.  These
      commands may not work correctly under "at" looping over windows.

      attrcolor attrib [attribute/color-modifier]

      This command can be used to highlight attributes by changing the color
      of the text. If the attribute attrib is in use, the specified
      attribute/color modifier is also applied. If no modifier is given, the
      current one is deleted. See the "STRING ESCAPES" chapter for the
      syntax of the modifier. Screen understands two pseudo-attributes, "i"
      stands for high-intensity foreground color and "I" for high-intensity
      background color.

      Examples:

           attrcolor b "R"

      Change the color to bright red if bold text is to be printed.

           attrcolor u "-u b"

      Use blue text instead of underline.

           attrcolor b ".I"

      Use bright colors for bold text. Most terminal emulators do this
      already.





                                   - 12 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           attrcolor i "+b"

      Make bright colored text also bold.

      autodetach on|off

      Sets whether screen will automatically detach upon hangup, which saves
      all your running programs until they are resumed with a screen -r
      command.  When turned off, a hangup signal will terminate screen and
      all the processes it contains. Autodetach is on by default.

      autonuke on|off

      Sets whether a clear screen sequence should nuke all the output that
      has not been written to the terminal. See also "obuflimit".

      backtick id lifespan autorefresh cmd args_

      backtick id

      Program the backtick command with the numerical id id.  The output of
      such a command is used for substitution of the "%`" string escape. The
      specified lifespan is the number of seconds the output is considered
      valid. After this time, the command is run again if a corresponding
      string escape is encountered.  The autorefresh parameter triggers an
      automatic refresh for caption and hardstatus strings after the
      specified number of seconds. Only the last line of output is used for
      substitution.

      If both the lifespan and the autorefresh parameters are zero, the
      backtick program is expected to stay in the background and generate
      output once in a while.  In this case, the command is executed right
      away and screen stores the last line of output. If a new line gets
      printed screen will automatically refresh the hardstatus or the
      captions.

      The second form of the command deletes the backtick command with the
      numerical id id.

      bce [on|off]

      Change background-color-erase setting. If "bce" is set to on, all
      characters cleared by an erase/insert/scroll/clear operation will be
      displayed in the current background color. Otherwise the default
      background color is used.

      bell_msg [message]

      When a bell character is sent to a background window, screen displays
      a notification in the message line.  The notification message can be
      re-defined by this command.  Each occurrence of `%' in message is



                                   - 13 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      replaced by the number of the window to which a bell has been sent,
      and each occurrence of `^G' is replaced by the definition for bell in
      your termcap (usually an audible bell).  The default message is

                       'Bell in window %n'

      An empty message can be supplied to the "bell_msg" command to suppress
      output of a message line (bell_msg "").  Without parameter, the
      current message is shown.

      bind [class] key [

      Bind a command to a key.  By default, most of the commands provided by
      screen are bound to one or more keys as indicated in the "DEFAULT KEY
      BINDINGS" section, e.g. the command to create a new window is bound to
      "C-c" and "c".  The "bind" command can be used to redefine the key
      bindings and to define new bindings.  The key argument is either a
      single character, a two-character sequence of the form "^x" (meaning
      "C-x"), a backslash followed by an octal number (specifying the ASCII
      code of the character), or a backslash followed by a second character,
      such as "\^" or "\\".  The argument can also be quoted, if you like.
      If no further argument is given, any previously established binding
      for this key is removed.  The command argument can be any command
      listed in this section.

      If a command class is specified via the "-c" option, the key is bound
      for the specified class. Use the "command" command to activate a
      class. Command classes can be used to create multiple command keys or
      multi-character bindings.

      Some examples:

                  bind ' ' windows
                  bind ^k
                  bind k
                  bind K kill
                  bind ^f screen telnet foobar
                  bind \033 screen -ln -t root -h 1000 9 su

      would bind the space key to the command that displays a list of
      windows (so that the command usually invoked by "C-a C-w" would also
      be available as "C-a space"). The next three lines remove the default
      kill binding from "C-a C-k" and "C-a k". "C-a K" is then bound to the
      kill command. Then it binds "C-f" to the command "create a window with
      a TELNET connection to foobar", and bind "escape" to the command that
      creates an non-login window with a.k.a. "root" in slot #9, with a
      superuser shell and a scrollback buffer of 1000 lines.

                  bind -c demo1 0 select 10
                  bind -c demo1 1 select 11
                  bind -c demo1 2 select 12



                                   - 14 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



                  bindkey "^B" command -c demo1

      makes "C-b 0" select window 10, "C-b 1" window 11, etc.

                  bind -c demo2 0 select 10
                  bind -c demo2 1 select 11
                  bind -c demo2 2 select 12
                  bind - command -c demo2

      makes "C-a - 0" select window 10, "C-a - 1" window 11, etc.

      bindkey [-d] [-m] [

      This command manages screen's input translation tables. Every entry in
      one of the tables tells screen how to react if a certain sequence of
      characters is encountered. There are three tables: one that should
      contain actions programmed by the user, one for the default actions
      used for terminal emulation and one for screen's copy mode to do
      cursor movement. See section "INPUT TRANSLATION" for a list of default
      key bindings.

      If the -d option is given, bindkey modifies the default table, -m
      changes the copy mode table and with neither option the user table is
      selected.  The argument string is the sequence of characters to which
      an action is bound. This can either be a fixed string or a termcap
      keyboard capability name (selectable with the -k option).

      Some keys on a VT100 terminal can send a different string if
      application mode is turned on (e.g the cursor keys).  Such keys have
      two entries in the translation table. You can select the application
      mode entry by specifying the -a option.

      The -t option tells screen not to do inter-character timing. One
      cannot turn off the timing if a termcap capability is used.

      Cmd can be any of screen's commands with an arbitrary number of args.
      If cmd is omitted the key-binding is removed from the table.

      Here are some examples of keyboard bindings:

              bindkey -d
      Show all of the default key bindings. The application mode entries are
      marked with [A].

              bindkey -k k1 select 1
      Make the "F1" key switch to window one.

              bindkey -t foo stuff barfoo
      Make "foo" an abbreviation of the word "barfoo". Timeout is disabled
      so that users can type slowly.




                                   - 15 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



              bindkey "\024" mapdefault
      This key-binding makes "^T" an escape character for key-bindings. If
      you did the above "stuff barfoo" binding, you can enter the word "foo"
      by typing "^Tfoo". If you want to insert a "^T" you have to press the
      key twice (i.e., escape the escape binding).

              bindkey -k F1 command
      Make the F11 (not F1!) key an alternative screen escape (besides ^A).

      break[duration]

      Send a break signal for duration*0.25 seconds to this window.  For
      non-Posix systems the time interval may be rounded up to full seconds.
      Most useful if a character device is attached to the window rather
      than a shell process (See also chapter "WINDOW TYPES"). The maximum
      duration of a break signal is limited to 15 seconds.

      blanker

      Activate the screen blanker. First the screen is cleared. If no
      blanker program is defined, the cursor is turned off, otherwise, the
      program is started and it's output is written to the screen.  The
      screen blanker is killed with the first keypress, the read key is
      discarded.

      This command is normally used together with the "idle" command.

      blankerprg [program-args]

      Defines a blanker program. Disables the blanker program if an empty
      argument is given. Shows the currently set blanker program if no
      arguments are given.

      breaktype [tcsendbreak|TIOCSBRK|

      Choose one of the available methods of generating a break signal for
      terminal devices. This command should affect the current window only.
      But it still behaves identical to "defbreaktype". This will be changed
      in the future.  Calling "breaktype" with no parameter displays the
      break method for the current window.

      bufferfile [exchange-file]

      Change the filename used for reading and writing with the paste
      buffer.  If the optional argument to the "bufferfile" command is
      omitted, the default setting ("/tmp/screen-exchange") is reactivated.
      The following example will paste the system's password file into the
      screen window (using the paste buffer, where a copy remains):

                  C-a : bufferfile /etc/passwd
                  C-a < C-a ]



                                   - 16 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



                  C-a : bufferfile

      bumpleft

      Swaps window with previous one on window list.

      bumpright

      Swaps window with next one on window list.

      c1 [on|off]

      Change c1 code processing. "C1 on" tells screen to treat the input
      characters between 128 and 159 as control functions.  Such an 8-bit
      code is normally the same as ESC followed by the corresponding 7-bit
      code. The default setting is to process c1 codes and can be changed
      with the "defc1" command. Users with fonts that have usable characters
      in the c1 positions may want to turn this off.

      caption [ top | bottom ] always|splitonly[string]

      caption string [string]

      This command controls the display of the window captions. Normally a
      caption is only used if more than one window is shown on the display
      (split screen mode). But if the type is set to always screen shows a
      caption even if only one window is displayed. The default is
      splitonly.

      The second form changes the text used for the caption. You can use all
      escapes from the "STRING ESCAPES" chapter. Screen uses a default of
      `%3n %t'.

      You can mix both forms by providing a string as an additional
      argument.

      You can have the caption displayed either at the top or bottom of the
      window.  The default is bottom.

      charset set

      Change the current character set slot designation and charset mapping.
      The first four character of set are treated as charset designators
      while the fifth and sixth character must be in range '0' to '3' and
      set the GL/GR charset mapping. On every position a '.' may be used to
      indicate that the corresponding charset/mapping should not be changed
      (set is padded to six characters internally by appending '.' chars).
      New windows have "BBBB02" as default charset, unless a "encoding"
      command is active.
      The current setting can be viewed with the "info" command.




                                   - 17 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      chdir [directory]

      Change the current directory of screen to the specified directory or,
      if called without an argument, to your home directory (the value of
      the environment variable $HOME).  All windows that are created by
      means of the "screen" command from within ".screenrc" or by means of
      "C-a : screen " or "C-a c" use this as their default directory.
      Without a chdir command, this would be the directory from which screen
      was invoked.

      Hardcopy and log files are always written to the window's default
      directory, not the current directory of the process running in the
      window.  You can use this command multiple times in your .screenrc to
      start various windows in different default directories, but the last
      chdir value will affect all the windows you create interactively.

      cjkwidth [ on | off ]

      Treat ambiguous width characters as full/half width.

      clear

      Clears the current window and saves its image to the scrollback
      buffer.

      collapse

      Reorders window on window list, removing number gaps between them.

      colon [prefix]

      Allows you to enter ".screenrc" command lines. Useful for on-the-fly
      modification of key bindings, specific window creation and changing
      settings. Note that the "set" keyword no longer exists! Usually
      commands affect the current window rather than default settings for
      future windows. Change defaults with commands starting with 'def'.

      If you consider this as the `Ex command mode' of screen, you may
      regard "C-a esc" (copy mode) as its `Vi command mode'.

      command [-c class]

      This command has the same effect as typing the screen escape character
      (^A). It is probably only useful for key bindings.  If the "-c" option
      is given, select the specified command class.  See also "bind" and
      "bindkey".

      compacthist [on|off]

      This tells screen whether to suppress trailing blank lines when
      scrolling up text into the history buffer.



                                   - 18 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      console [on|off]

      Grabs or un-grabs the machines console output to a window.  Note: Only
      the owner of /dev/console can grab the console output.  This command
      is only available if the machine supports the ioctl TIOCCONS.

      copy

      Enter copy/scrollback mode. This allows you to copy text from the
      current window and its history into the paste buffer. In this mode a
      vi-like `full screen editor' is active:
      The editor's movement keys are:

      allbox tab(@); l l.  T{ h, C-h,
      left arrow T}@move the cursor left.  T{ j, C-n,
      down arrow T}@move the cursor down.  T{ k, C-p,
      up arrow T}@move the cursor up.  T{ l ('el'),
      right arrow T}@move the cursor right.  0 (zero) C-a@move to the
      leftmost column.  + and -@positions one line up and down.  H, M and
      L@T{ move the cursor to the leftmost column of the top, center or
      bottom line of the window. T} |@moves to the specified absolute
      column.  g or home@moves to the beginning of the buffer.  G or end@T{
      moves to the specified absolute line (default: end of buffer).  T}
      %@jumps to the specified percentage of the buffer.  ^ or $@T{ move to
      the leftmost column, to the first or last non-whitespace character on
      the line.  T} w, b, and e@move the cursor word by word.  B, E@move the
      cursor WORD by WORD (as in vi).  f/F, t/T@T{ move the cursor
      forward/backward to the next occurence of the target. (eg, '3fy' will
      move the cursor to the 3rd 'y' to the right.) T} ; and ,@T{ Repeat the
      last f/F/t/T command in the same/opposite direction.  T} C-e and C-
      y@T{ scroll the display up/down by one line while preserving the
      cursor position.  T} C-u and C-d@T{ scroll the display up/down by the
      specified amount of lines while preserving the cursor position.
      (Default: half screen-full). T} C-b and C-f@scroll the display up/down
      a full screen.


      Note: Emacs style movement keys can be customized by a .screenrc
      command.  (E.g. markkeys "h=^B:l=^F:$=^E") There is no simple method
      for a full emacs-style keymap, as this involves multi-character codes.

      Some keys are defined to do mark and replace operations.

      The copy range is specified by setting two marks. The text between
      these marks will be highlighted. Press:

           space or enter to set the first or second mark respectively. If
           mousetrack is set to `on', marks can also be set using left mouse
           click.





                                   - 19 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           Y and y used to mark one whole line or to mark from start of
           line.

           W marks exactly one word.

      Any of these commands can be prefixed with a repeat count number by
      pressing digits

           0..9 which is taken as a repeat count.

      Example: "C-a C-[ H 10 j 5 Y" will copy lines 11 to 15 into the paste
      buffer.

      The folllowing search keys are defined:

           / Vi-like search forward.

           ? Vi-like search backward.

           C-a s Emacs style incremental search forward.

           C-r Emacs style reverse i-search.

           n Find next search pattern.

           N Find previous search pattern.


      There are however some keys that act differently than in vi.  Vi does
      not allow one to yank rectangular blocks of text, but screen does.
      Press: c or C to set the left or right margin respectively. If no
      repeat count is given, both default to the current cursor position.

      Example: Try this on a rather full text screen:

           "C-a [ M 20 l SPACE c 10 l 5 j C SPACE".

      This moves one to the middle line of the screen, moves in 20 columns
      left, marks the beginning of the paste buffer, sets the left column,
      moves 5 columns down, sets the right column, and then marks the end of
      the paste buffer. Now try:

           "C-a [ M 20 l SPACE 10 l 5 j SPACE"

      and notice the difference in the amount of text copied.

      J joins lines. It toggles between 4 modes: lines separated by a
      newline character (012), lines glued seamless, lines separated by a
      single whitespace and comma separated lines. Note that you can prepend
      the newline character with a carriage return character, by issuing a
      "crlf on".



                                   - 20 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      v or V is for all the vi users with ":set numbers" - it toggles the
      left margin between column 9 and 1. Press

      a before the final space key to toggle in append mode. Thus the
      contents of the paste buffer will not be overwritten, but is appended
      to.

      A toggles in append mode and sets a (second) mark.

      > sets the (second) mark and writes the contents of the paste buffer
      to the screen-exchange file (/tmp/screen-exchange per default) once
      copy-mode is finished.

      This example demonstrates how to dump the whole scrollback buffer to
      that file: "C-A [ g SPACE G $ >".

      C-g gives information about the current line and column.

      x or o exchanges the first mark and the current cursor position. You
      can use this to adjust an already placed mark.

      C-l ('el') will redraw the screen.

      @ does nothing. Does not even exit copy mode.

      All keys not described here exit copy mode.

      copy_reg [key]

      No longer exists, use "readreg" instead.

      crlf [on|off]

      This affects the copying of text regions with the `C-a [' command. If
      it is set to `on', lines will be separated by the two character
      sequence `CR' - `LF'. Otherwise (default) only `LF' is used.  When no
      parameter is given, the state is toggled.

      debug on|off

      Turns runtime debugging on or off. If screen has been compiled with
      option -DDEBUG debugging available and is turned on per default. Note
      that this command only affects debugging output from the main "SCREEN"
      process correctly. Debug output from attacher processes can only be
      turned off once and forever.

      defc1 on|off

      Same as the c1 command except that the default setting for new windows
      is changed. Initial setting is `on'.




                                   - 21 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      defautonuke on|off

      Same as the autonuke command except that the default setting for new
      displays is changed. Initial setting is `off'.  Note that you can use
      the special `AN' terminal capability if you want to have a dependency
      on the terminal type.

      defbce on|off

      Same as the bce command except that the default setting for new
      windows is changed. Initial setting is `off'.

      defbreaktype [tcsendbreak|TIOCSBRK|

      Choose one of the available methods of generating a break signal for
      terminal devices. The preferred methods are tcsendbreak and TIOCSBRK.
      The third, TCSBRK, blocks the complete screen session for the duration
      of the break, but it may be the only way to generate long breaks.
      Tcsendbreak and TIOCSBRK may or may not produce long breaks with
      spikes (e.g. 4 per second). This is not only system-dependent, this
      also differs between serial board drivers.  Calling "defbreaktype"
      with no parameter displays the current setting.

      defcharset [set]

      Like the charset command except that the default setting for new
      windows is changed. Shows current default if called without argument.

      defdynamictitle on|off

      Set default behaviour for new windows regarding if screen should
      change window title when seeing proper escape sequence. See also
      "TITLES (naming windows)" section.

      defescape xy

      Set the default command characters. This is equivalent to the "escape"
      except that it is useful multiuser sessions only. In a multiuser
      session "escape" changes the command character of the calling user,
      where "defescape" changes the default command characters for users
      that will be added later.

      defflow on|off|auto

      Same as the flow command except that the default setting for new
      windows is changed. Initial setting is `auto'.  Specifying "defflow
      auto interrupt" is the same as the command-line options -fa and -i.

      defgr on|off





                                   - 22 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      Same as the gr command except that the default setting for new windows
      is changed. Initial setting is `off'.

      defhstatus [status]

      The hardstatus line that all new windows will get is set to status.
      This command is useful to make the hardstatus of every window display
      the window number or title or the like.  Status may contain the same
      directives as in the window messages, but the directive escape
      character is '^E' (octal 005) instead of '%'.  This was done to make a
      misinterpretation of program generated hardstatus lines impossible.
      If the parameter status is omitted, the current default string is
      displayed.  Per default the hardstatus line of new windows is empty.

      defencoding enc

      Same as the encoding command except that the default setting for new
      windows is changed. Initial setting is the encoding taken from the
      terminal.

      deflog on|off

      Same as the log command except that the default setting for new
      windows is changed. Initial setting is `off'.

      deflogin on|off

      Same as the login command except that the default setting for new
      windows is changed. This is initialized with `on' as distributed (see
      config.h.in).

      defmode mode

      The mode of each newly allocated pseudo-tty is set to mode.  Mode is
      an octal number.  When no "defmode" command is given, mode 0622 is
      used.

      defmonitor on|off

      Same as the monitor command except that the default setting for new
      windows is changed. Initial setting is `off'.

      defmousetrack on|off

      Same as the mousetrack command except that the default setting for new
      windows is changed. Initial setting is `off'.

      defnonblock on|off|numsecs

      Same as the nonblock command except that the default setting for
      displays is changed. Initial setting is `off'.



                                   - 23 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      defobuflimit limit

      Same as the obuflimit command except that the default setting for new
      displays is changed. Initial setting is 256 bytes.  Note that you can
      use the special 'OL' terminal capability if you want to have a
      dependency on the terminal type.

      defscrollback num

      Same as the scrollback command except that the default setting for new
      windows is changed. Initial setting is 100.

      defshell command

      Synonym to the shell .screenrc command. See there.

      defsilence on|off

      Same as the silence command except that the default setting for new
      windows is changed. Initial setting is `off'.

      defslowpaste msec

      Same as the slowpaste command except that the default setting for new
      windows is changed. Initial setting is 0 milliseconds, meaning `off'.

      defutf8 on|off

      Same as the utf8 command except that the default setting for new
      windows is changed. Initial setting is `on' if screen was started with
      "-U", otherwise `off'.

      defwrap on|off

      Same as the wrap command except that the default setting for new
      windows is changed. Initially line-wrap is on and can be toggled with
      the "wrap" command ("C-a r") or by means of "C-a : wrap on|off".

      defwritelock on|off|auto

      Same as the writelock command except that the default setting for new
      windows is changed. Initially writelocks will off.

      defzombie [keys]

      Synonym to the zombie command. Both currently change the default.  See
      there.

      detach [-h]





                                   - 24 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      Detach the screen session (disconnect it from the terminal and put it
      into the background).  This returns you to the shell where you invoked
      screen.  A detached screen can be resumed by invoking screen with the
      -r option (see also section "COMMAND-LINE OPTIONS"). The -h option
      tells screen to immediately close the connection to the terminal
      ("hangup").

      dinfo

      Show what screen thinks about your terminal. Useful if you want to
      know why features like color or the alternate charset don't work.

      displays

      Shows a tabular listing of all currently connected user front-ends
      (displays).  This is most useful for multiuser sessions.  The
      following keys can be used in displays list:

      allbox tab(@); l l.  k, C-p, or up@Move up one line.  j, C-n, or
      down@Move down one line.  C-a or home@Move to the first line.  C-e or
      end@Move to the last line.  C-u or C-d@Move one half page up or down.
      C-b or C-f@Move one full page up or down.  mouseclick@T{ Move to the
      selected line. Available when "mousetrack" is set to on.  T}
      space@Refresh the list d@Detach that display D@Power detach that
      display C-g, enter, or escape@Exit the list

      The following is an example of what "displays" could look like:
           xterm 80x42 jnweiger@/dev/ttyp4     0(m11)   &rWx
           facit 80x24 mlschroe@/dev/ttyhf nb 11(tcsh)   rwx
           xterm 80x42 jnhollma@/dev/ttyp5     0(m11)   &R.x
            (A)   (B)     (C)     (D)     (E) (F)(G)   (H)(I)

      The legend is as follows:

           (A) The terminal type known by screen for this display.

      (B) Displays geometry as width x height.

      (C) Username who is logged in at the display.

      (D) Device name of the display or the attached device

      (E) Display is in blocking or nonblocking mode.  The available modes
      are "nb", "NB", "Z<", "Z>", and "BL".

      (F) Number of the window

      (G) Name/title of window

      (H) Whether the window is shared




                                   - 25 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      (I) Window permissions. Made up of three characters:

                 (1st character)
                    - : no read
                    r : read
                    R : read only due to foreign wlock
                 (2nd character)
                    - : no write
                    . : write suppressed by foreign wlock
                    w : write
                    W : own wlock
                 (3rd character)
                    - : no execute
                    x : execute
                "Displays" needs a region size of at least 10 characters
                wide and 5 characters high in order to display.

           digraph [preset[unicode-value]]

           This command prompts the user for a digraph sequence. The next
           two characters typed are looked up in a builtin table and the
           resulting character is inserted in the input stream. For example,
           if the user enters 'a"', an a-umlaut will be inserted. If the
           first character entered is a 0 (zero), screen will treat the
           following characters (up to three) as an octal number instead.
           The optional argument preset is treated as user input, thus one
           can create an "umlaut" key.  For example the command "bindkey ^K
           digraph '"'" enables the user to generate an a-umlaut by typing
           CTRL-K a.  When a non-zero unicode-value is specified, a new
           digraph is created with the specified preset. The digraph is
           unset if a zero value is provided for the unicode-value.

           dumptermcap

           Write the termcap entry for the virtual terminal optimized for
           the currently active window to the file ".termcap" in the user's
           "$HOME/.screen" directory (or wherever screen stores its sockets.
           See the "FILES" section below).  This termcap entry is identical
           to the value of the environment variable $TERMCAP that is set up
           by screen for each window. For terminfo based systems you will
           need to run a converter like captoinfo and then compile the entry
           with tic.

           dynamictitle on|off

           Change behaviour for windows regarding if screen should change
           window title when seeing proper escape sequence. See also "TITLES
           (naming windows)" section.

           echo [-n] message




                                   - 26 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           The echo command may be used to annoy screen users with a
           'message of the day'. Typically installed in a global
           /local/etc/screenrc. The option "-n" may be used to suppress the
           line feed.  See also "sleep".  Echo is also useful for online
           checking of environment variables.

           encoding enc [enc]

           Tell screen how to interpret the input/output. The first argument
           sets the encoding of the current window. Each window can emulate
           a different encoding. The optional second parameter overwrites
           the encoding of the connected terminal. It should never be needed
           as screen uses the locale setting to detect the encoding.  There
           is also a way to select a terminal encoding depending on the
           terminal type by using the "KJ" termcap entry.

           Supported encodings are eucJP, SJIS, eucKR, eucCN, Big5, GBK,
           KOI8-R, KOI8-U, CP1251, UTF-8, ISO8859-2, ISO8859-3, ISO8859-4,
           ISO8859-5, ISO8859-6, ISO8859-7, ISO8859-8, ISO8859-9, ISO8859-
           10, ISO8859-15, jis.

           See also "defencoding", which changes the default setting of a
           new window.

           escape xy

           Set the command character to x and the character generating a
           literal command character (by triggering the "meta" command) to y
           (similar to the -e option).  Each argument is either a single
           character, a two-character sequence of the form "^x" (meaning
           "C-x"), a backslash followed by an octal number (specifying the
           ASCII code of the character), or a backslash followed by a second
           character, such as "\^" or "\\".  The default is "^Aa".

           eval command1[command2 ]

           Parses and executes each argument as separate command.

           exec [[fdpat]newcommand [

           Run a unix subprocess (specified by an executable path newcommand
           and its optional arguments) in the current window. The flow of
           data between newcommands stdin/stdout/stderr, the process
           originally started in the window (let us call it "application-
           process") and screen itself (window) is controlled by the file
           descriptor pattern fdpat.  This pattern is basically a three
           character sequence representing stdin, stdout and stderr of
           newcommand. A dot (.) connects the file descriptor to screen.  An
           exclamation mark (!) causes the file descriptor to be connected
           to the application-process. A colon (:) combines both.  User
           input will go to newcommand unless newcommand receives the



                                   - 27 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           application-process' output (fdpats first character is `!' or
           `:') or a pipe symbol (|) is added (as a fourth character) to the
           end of fdpat.

           Invoking `exec' without arguments shows name and arguments of the
           currently running subprocess in this window. Only one subprocess
           a time can be running in each window.

           When a subprocess is running the `kill' command will affect it
           instead of the windows process.

           Refer to the postscript file `doc/fdpat.ps' for a confusing
           illustration of all 21 possible combinations. Each drawing shows
           the digits 2,1,0 representing the three file descriptors of
           newcommand. The box marked `W' is the usual pty that has the
           application-process on its slave side.  The box marked `P' is the
           secondary pty that now has screen at its master side.

           Abbreviations: Whitespace between the word `exec' and fdpat and
           the command can be omitted. Trailing dots and a fdpat consisting
           only of dots can be omitted. A simple `|' is synonymous for the
           pattern `!..|'; the word exec can be omitted here and can always
           be replaced by `!'.

           Examples:

                exec  /bin/sh

                exec /bin/sh

                !/bin/sh

                     Creates another shell in the same window, while the
                     original shell is still running. Output of both shells
                     is displayed and user input is sent to the new /bin/sh.

                exec !.. stty 19200

                exec ! stty 19200

                !!stty 19200

                     Set the speed of the window's tty. If your stty command
                     operates on stdout, then add another `!'.

                exec !..| less

                |less

                     This adds a pager to the window output. The special
                     character `|' is needed to give the user control over



                                   - 28 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



                     the pager although it gets its input from the window's
                     process. This works, because less listens on stderr (a
                     behavior that screen would not expect without the `|')
                     when its stdin is not a tty. Less versions newer than
                     177 fail miserably here; good old pg still works.

                !:sed -n s/.*Error.*/\007/p

                     Sends window output to both, the user and the sed
                     command. The sed inserts an additional bell character
                     (oct. 007) to the window output seen by screen.  This
                     will cause "Bell in window x" messages, whenever the
                     string "Error" appears in the window.

           fit

           Change the window size to the size of the current region. This
           command is needed because screen doesn't adapt the window size
           automatically if the window is displayed more than once.

           flow [on|off|auto]

           Sets the flow-control mode for this window.  Without parameters
           it cycles the current window's flow-control setting from
           "automatic" to "on" to "off".  See the discussion on "FLOW-
           CONTROL" later on in this document for full details and note,
           that this is subject to change in future releases.  Default is
           set by `defflow'.

           focus [up|down|

           Move the input focus to the next region. This is done in a cyclic
           way so that the top region is selected after the bottom one. If
           no subcommand is given it defaults to `down'. `up' cycles in the
           opposite order, `top' and `bottom' go to the top and bottom
           region respectively. Useful bindings are (j and k as in vi)
               bind j focus down
               bind k focus up
               bind t focus top
               bind b focus bottom
           Note that k is traditionally bound to the kill command.

           focusminsize [ ( width|max|_ ) ( height|max|_ ) ]

           This forces any currently selected region to be automatically
           resized at least a certain width and height. All other
           surrounding regions will be resized in order to accommodate.
           This constraint follows everytime the "focus" command is used.
           The "resize" command can be used to increase either dimension of
           a region, but never below what is set with "focusminsize". The
           underscore `_' is a synonym for max. Setting a width and height



                                   - 29 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           of `0 0' (zero zero) will undo any constraints and allow for
           manual resizing.  Without any parameters, the minimum width and
           height is shown.

           gr [on|off]

           Turn GR charset switching on/off. Whenever screen sees an input
           character with the 8th bit set, it will use the charset stored in
           the GR slot and print the character with the 8th bit stripped.
           The default (see also "defgr") is not to process GR switching
           because otherwise the ISO88591 charset would not work.

           group [grouptitle]

           Change or show the group the current window belongs to. Windows
           can be moved around between different groups by specifying the
           name of the destination group. Without specifying a group, the
           title of the current group is displayed.

           hardcopy [-h] [file]

           Writes out the currently displayed image to the file file, or, if
           no filename is specified, to hardcopy.n in the default directory,
           where n is the number of the current window. This either appends
           or overwrites the file if it exists. See below.  If the option -h
           is specified, dump also the contents of the scrollback buffer.

           hardcopy_append on|off

           If set to "on", screen will append to the "hardcopy.n" files
           created by the command "C-a h", otherwise these files are
           overwritten each time.  Default is `off'.

           hardcopydir directory

           Defines a directory where hardcopy files will be placed. If
           unset, hardcopys are dumped in screen's current working
           directory.

           hardstatus [on|off]

           hardstatus [always]firstline|lastline|message|

           hardstatus string[string]

           This command configures the use and emulation of the terminal's
           hardstatus line. The first form toggles whether screen will use
           the hardware status line to display messages. If the flag is set
           to `off', these messages are overlaid in reverse video mode at
           the display line. The default setting is `on'.




                                   - 30 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           The second form tells screen what to do if the terminal doesn't
           have a hardstatus line (i.e. the termcap/terminfo capabilities
           "hs", "ts", "fs" and "ds" are not set).  When
           "firstline/lastline" is used, screen will reserve the first/last
           line of the display for the hardstatus. "message" uses screen's
           message mechanism and "ignore" tells screen never to display the
           hardstatus.  If you prepend the word "always" to the type (e.g.,
           "alwayslastline"), screen will use the type even if the terminal
           supports a hardstatus.

           The third form specifies the contents of the hardstatus line.
           '%h' is used as default string, i.e., the stored hardstatus of
           the current window (settable via "ESC]0;<string>^G" or
           "ESC_<string>ESC\") is displayed.  You can customize this to any
           string you like including the escapes from the "STRING ESCAPES"
           chapter. If you leave out the argument string, the current string
           is displayed.

           You can mix the second and third form by providing the string as
           additional argument.

           height [-w|-d] [

           Set the display height to a specified number of lines. When no
           argument is given it toggles between 24 and 42 lines display. You
           can also specify a width if you want to change both values.  The
           -w option tells screen to leave the display size unchanged and
           just set the window size, -d vice versa.

           help[class]

           Not really a online help, but displays a help screen showing you
           all the key bindings.  The first pages list all the internal
           commands followed by their current bindings.  Subsequent pages
           will display the custom commands, one command per key.  Press
           space when you're done reading each page, or return to exit
           early.  All other characters are ignored. If the "-c" option is
           given, display all bound commands for the specified command
           class.  See also "DEFAULT KEY BINDINGS" section.

           history

           Usually users work with a shell that allows easy access to
           previous commands.  For example csh has the command "!!" to
           repeat the last command executed. Screen allows you to have a
           primitive way of re-calling "the command that started ": You
           just type the first letter of that command, then hit `C-a {' and
           screen tries to find a previous line that matches with the
           `prompt character' to the left of the cursor. This line is pasted
           into this window's input queue.  Thus you have a crude command
           history (made up by the visible window and its scrollback



                                   - 31 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           buffer).

           hstatus status

           Change the window's hardstatus line to the string status.

           idle [timeout[cmd-args]]

           Sets a command that is run after the specified number of seconds
           inactivity is reached. This command will normally be the
           "blanker" command to create a screen blanker, but it can be any
           screen command.  If no command is specified, only the timeout is
           set. A timeout of zero (or the special timeout off) disables the
           timer.  If no arguments are given, the current settings are
           displayed.

           ignorecase [on|off]

           Tell screen to ignore the case of characters in searches. Default
           is `off'. Without any options, the state of ignorecase is
           toggled.

           info

           Uses the message line to display some information about the
           current window: the cursor position in the form "(column,row)"
           starting with "(1,1)", the terminal width and height plus the
           size of the scrollback buffer in lines, like in "(80,24)+50", the
           current state of window XON/XOFF flow control is shown like this
           (See also section FLOW CONTROL):

             +flow     automatic flow control, currently on.
             -flow     automatic flow control, currently off.
             +(+)flow  flow control enabled. Agrees with automatic control.
             -(+)flow  flow control disabled. Disagrees with automatic control.
             +(-)flow  flow control enabled. Disagrees with automatic control.
             -(-)flow  flow control disabled. Agrees with automatic control.

           The current line wrap setting (`+wrap' indicates enabled, `-wrap'
           not) is also shown. The flags `ins', `org', `app', `log', `mon'
           or `nored' are displayed when the window is in insert mode,
           origin mode, application-keypad mode, has output logging,
           activity monitoring or partial redraw enabled.

           The currently active character set (G0, G1, G2, or G3) and in
           square brackets the terminal character sets that are currently
           designated as G0 through G3 is shown. If the window is in UTF-8
           mode, the string "UTF-8" is shown instead.

           Additional modes depending on the type of the window are
           displayed at the end of the status line (See also chapter "WINDOW



                                   - 32 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           TYPES").

           If the state machine of the terminal emulator is in a non-default
           state, the info line is started with a string identifying the
           current state.

           For system information use the "time" command.

           ins_reg [key]

           No longer exists, use "paste" instead.

           kill

           Kill current window.

           If there is an `exec' command running then it is killed.
           Otherwise the process (shell) running in the window receives a
           HANGUP condition, the window structure is removed and screen
           (your display) switches to another window.  When the last window
           is destroyed, screen exits.  After a kill screen switches to the
           previously displayed window.

           Note: Emacs users should keep this command in mind, when killing
           a line.  It is recommended not to use "C-a" as the screen escape
           key or to rebind kill to "C-a K".

           lastmsg

           Redisplay the last contents of the message/status line.  Useful
           if you're typing when a message appears, because  the message
           goes away when you press a key (unless your terminal has a
           hardware status line).  Refer to the commands "msgwait" and
           "msgminwait" for fine tuning.

           layout new [title]

           Create a new layout. The screen will change to one whole region
           and be switched to the blank window. From here, you build the
           regions and the windows they show as you desire. The new layout
           will be numbered with the smallest available integer, starting
           with zero. You can optionally give a title to your new layout.
           Otherwise, it will have a default title of "layout". You can
           always change the title later by using the command layout title.

           layout remove [n|title]

           Remove, or in other words, delete the specified layout. Either
           the number or the title can be specified. Without either
           specification, screen will remove the current layout.




                                   - 33 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           Removing a layout does not affect your set windows or regions.

           layout next

           Switch to the next layout available

           layout prev

           Switch to the previous layout available

           layout select [n|title]

           Select the desired layout. Either the number or the title can be
           specified. Without either specification, screen will prompt and
           ask which screen is desired. To see which layouts are available,
           use the layout show command.

           layout show

           List on the message line the number(s) and title(s) of the
           available layout(s). The current layout is flagged.

           layout title [title]

           Change or display the title of the current layout. A string given
           will be used to name the layout. Without any options, the current
           title and number is displayed on the message line.

           layout number [n]

           Change or display the number of the current layout. An integer
           given will be used to number the layout. Without any options, the
           current number and title is displayed on the message line.

           layout attach [title|:last]

           Change or display which layout to reattach back to. The default
           is :last, which tells screen to reattach back to the last used
           layout just before detachment. By supplying a title, You can
           instruct screen to reattach to a particular layout regardless
           which one was used at the time of detachment. Without any
           options, the layout to reattach to will be shown in the message
           line.

           layout save [n|title]

           Remember the current arrangement of regions. When used, screen
           will remember the arrangement of vertically and horizontally
           split regions. This arrangement is restored when a screen session
           is reattached or switched back from a different layout. If the
           session ends or the screen process dies, the layout arrangements



                                   - 34 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           are lost. The layout dump command should help in this siutation.
           If a number or title is supplied, screen will remember the
           arrangement of that particular layout. Without any options,
           screen will remember the current layout.

           Saving your regions can be done automatically by using the layout
           autosave command.

           layout autosave [on|off]

           Change or display the status of automatcally saving layouts. The
           default is on, meaning when screen is detached or changed to a
           different layout, the arrangement of regions and windows will be
           remembered at the time of change and restored upon return.  If
           autosave is set to off, that arrangement will only be restored to
           either to the last manual save, using layout save, or to when the
           layout was first created, to a single region with a single
           window. Without either an on or off, the current status is
           displayed on the message line.

           layout dump [filename]

           Write to a file the order of splits made in the current layout.
           This is useful to recreate the order of your regions used in your
           current layout. Only the current layout is recorded. While the
           order of the regions are recorded, the sizes of those regions and
           which windows correspond to which regions are not. If no filename
           is specified, the default is layout-dump, saved in the directory
           that the screen process was started in. If the file already
           exists, layout dump will append to that file. As an example:

                       C-a : layout dump /home/user/.screenrc

           will save or append the layout to the user's .screenrc file.

           license

           Display the disclaimer page. This is done whenever screen is
           started without options, which should be often enough. See also
           the "startup_message" command.

           lockscreen

           Lock this display.  Call a screenlock program (/local/bin/lck or
           /usr/bin/lock or a builtin if no other is available). Screen does
           not accept any command keys until this program terminates.
           Meanwhile processes in the windows may continue, as the windows
           are in the `detached' state. The screenlock program may be
           changed through the environment variable $LOCKPRG (which must be
           set in the shell from which screen is started) and is executed
           with the user's uid and gid.



                                   - 35 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           Warning: When you leave other shells unlocked and you have no
           password set on screen, the lock is void: One could easily re-
           attach from an unlocked shell. This feature should rather be
           called `lockterminal'.

           log [on|off]

           Start/stop writing output of the current window to a file
           "screenlog.n" in the window's default directory, where n is the
           number of the current window. This filename can be changed with
           the `logfile' command. If no parameter is given, the state of
           logging is toggled. The session log is appended to the previous
           contents of the file if it already exists. The current contents
           and the contents of the scrollback history are not included in
           the session log.  Default is `off'.

           logfile filename

           logfile flush secs

           Defines the name the log files will get. The default is
           "screenlog.%n". The second form changes the number of seconds
           screen will wait before flushing the logfile buffer to the file-
           system. The default value is 10 seconds.

           login [on|off]

           Adds or removes the entry in the utmp database file for the
           current window.  This controls if the window is `logged in'.
           When no parameter is given, the login state of the window is
           toggled.  Additionally to that toggle, it is convenient having a
           `log in' and a `log out' key. E.g. `bind I login on' and `bind O
           login off' will map these keys to be C-a I and C-a O.  The
           default setting (in config.h.in) should be "on" for a screen that
           runs under suid-root.  Use the "deflogin" command to change the
           default login state for new windows. Both commands are only
           present when screen has been compiled with utmp support.

           logtstamp [on|off]

           logtstamp after [secs]

           logtstamp string
           [string]

           This command controls logfile time-stamp mechanism of screen. If
           time-stamps are turned "on", screen adds a string containing the
           current time to the logfile after two minutes of inactivity.
           When output continues and more than another two minutes have
           passed, a second time-stamp is added to document the restart of
           the output. You can change this timeout with the second form of



                                   - 36 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           the command. The third form is used for customizing the time-
           stamp string (`-- %n:%t -- time-stamp -- %M/%d/%y %c:%s --\n' by
           default).

           mapdefault

           Tell screen that the next input character should only be looked
           up in the default bindkey table. See also "bindkey".

           mapnotnext

           Like mapdefault, but don't even look in the default bindkey
           table.

           maptimeout [timeout]

           Set the inter-character timer for input sequence detection to a
           timeout of timeout ms. The default timeout is 300ms. Maptimeout
           with no arguments shows the current setting.  See also "bindkey".

           markkeys string

           This is a method of changing the keymap used for copy/history
           mode.  The string is made up of oldchar=newchar pairs which are
           separated by `:'. Example: The string "B=^B:F=^F" will change the
           keys `C-b' and `C-f' to the vi style binding (scroll up/down fill
           page).  This happens to be the default binding for `B' and `F'.
           The command "markkeys h=^B:l=^F:$=^E" would set the mode for an
           emacs-style binding.  If your terminal sends characters, that
           cause you to abort copy mode, then this command may help by
           binding these characters to do nothing.  The no-op character is
           `@' and is used like this: "markkeys @=L=H" if you do not want to
           use the `H' or `L' commands any longer.  As shown in this
           example, multiple keys can be assigned to one function in a
           single statement.

           maxwin num

           Set the maximum window number screen will create. Doesn't affect
           already existing windows. The number can be increased only when
           there are no existing windows.

           meta

           Insert the command character (C-a) in the current window's input
           stream.

           monitor [on|off]

           Toggles activity monitoring of windows.  When monitoring is
           turned on and an affected window is switched into the background,



                                   - 37 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           you will receive the activity notification message in the status
           line at the first sign of output and the window will also be
           marked with an `@' in the window-status display.  Monitoring is
           initially off for all windows.

           mousetrack [on|off]

           This command determines whether screen will watch for mouse
           clicks. When this command is enabled, regions that have been
           split in various ways can be selected by pointing to them with a
           mouse and left-clicking them. Without specifying on or off, the
           current state is displayed. The default state is determined by
           the "defmousetrack" command.

           msgminwait sec

           Defines the time screen delays a new message when one message is
           currently displayed. The default is 1 second.

           msgwait sec

           Defines the time a message is displayed if screen is not
           disturbed by other activity. The default is 5 seconds.

           multiuser on|off

           Switch between singleuser and multiuser mode. Standard screen
           operation is singleuser. In multiuser mode the commands `acladd',
           `aclchg', `aclgrp' and `acldel' can be used to enable (and
           disable) other users accessing this screen session.

           nethack on|off

           Changes the kind of error messages used by screen.  When you are
           familiar with the game "nethack", you may enjoy the nethack-style
           messages which will often blur the facts a little, but are much
           funnier to read. Anyway, standard messages often tend to be
           unclear as well.
           This option is only available if screen was compiled with the
           NETHACK flag defined. The default setting is then determined by
           the presence of the environment variable $NETHACKOPTIONS and the
           file ~/.nethackrc - if either one is present, the default is on.

           next

           Switch to the next window.  This command can be used repeatedly
           to cycle through the list of windows.

           nonblock
                [on|off|numsecs




                                   - 38 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           Tell screen how to deal with user interfaces (displays) that
           cease to accept output. This can happen if a user presses ^S or a
           TCP/modem connection gets cut but no hangup is received. If
           nonblock is off (this is the default) screen waits until the
           display restarts to accept the output. If nonblock is on, screen
           waits until the timeout is reached (on is treated as 1s). If the
           display still doesn't receive characters, screen will consider it
           "blocked" and stop sending characters to it. If at some time it
           restarts to accept characters, screen will unblock the display
           and redisplay the updated window contents.

           number [[+|-]n]

           Change the current window's number. If the given number n is
           already used by another window, both windows exchange their
           numbers. If no argument is specified, the current window number
           (and title) is shown. Using `+' or `-' will change the window's
           number by the relative amount specified.

           obuflimit [limit]

           If the output buffer contains more bytes than the specified
           limit, no more data will be read from the windows. The default
           value is 256. If you have a fast display (like xterm), you can
           set it to some higher value. If no argument is specified, the
           current setting is displayed.

           only

           Kill all regions but the current one.

           other

           Switch to the window displayed previously. If this window does no
           longer exist, other has the same effect as next.

           partial on|off

           Defines whether the display should be refreshed (as with
           redisplay) after switching to the current window. This command
           only affects the current window.  To immediately affect all
           windows use the allpartial command.  Default is `off', of course.
           This default is fixed, as there is currently no defpartial
           command.

           password [crypted_pw]

           Present a crypted password in your ".screenrc" file and screen
           will ask for it, whenever someone attempts to resume a detached.
           This is useful if you have privileged programs running under
           screen and you want to protect your session from reattach



                                   - 39 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           attempts by another user masquerading as your uid (i.e. any
           superuser.) If no crypted password is specified, screen prompts
           twice for typing a password and places its encryption in the
           paste buffer.  Default is `none', this disables password
           checking.

           paste [registers [dest_reg]]

           Write the (concatenated) contents of the specified registers to
           the stdin queue of the current window. The register '.' is
           treated as the paste buffer. If no parameter is given the user is
           prompted for a single register to paste.  The paste buffer can be
           filled with the copy, history and readbuf commands. Other
           registers can be filled with the register, readreg and paste
           commands.  If paste is called with a second argument, the
           contents of the specified registers is pasted into the named
           destination register rather than the window. If '.' is used as
           the second argument, the displays paste buffer is the
           destination.  Note, that "paste" uses a wide variety of
           resources: Whenever a second argument is specified no current
           window is needed. When the source specification only contains
           registers (not the paste buffer) then there need not be a current
           display (terminal attached), as the registers are a global
           resource. The paste buffer exists once for every user.

           pastefont [on|off]

           Tell screen to include font information in the paste buffer. The
           default is not to do so. This command is especially useful for
           multi character fonts like kanji.

           pow_break

           Reopen the window's terminal line and send a break condition. See
           `break'.

           pow_detach

           Power detach. Mainly the same as detach, but also sends a HANGUP
           signal to the parent process of screen.  CAUTION: This will
           result in a logout, when screen was started from your login-
           shell.

           pow_detach_msg [message]

           The message specified here is output whenever a `Power detach'
           was performed. It may be used as a replacement for a logout
           message or to reset baud rate, etc. Without parameter, the
           current message is shown.





                                   - 40 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           prev

           Switch to the window with the next lower number.  This command
           can be used repeatedly to cycle through the list of windows.

           printcmd [cmd]

           If cmd is not an empty string, screen will not use the terminal
           capabilities "po/pf" if it detects an ansi print sequence ESC [ 5
           i, but pipe the output into cmd.  This should normally be a
           command like "lpr" or "'cat > /tmp/scrprint'".  printcmd without
           a command displays the current setting.  The ansi sequence ESC \
           ends printing and closes the pipe.

           Warning: Be careful with this command! If other user have write
           access to your terminal, they will be able to fire off print
           commands.

           process [key]

           Stuff the contents of the specified register into screen's input
           queue. If no argument is given you are prompted for a register
           name. The text is parsed as if it had been typed in from the
           user's keyboard. This command can be used to bind multiple
           actions to a single key.

           quit

           Kill all windows and terminate screen.  Note that on VT100-style
           terminals the keys C-4 and C-\ are identical.  This makes the
           default bindings dangerous: Be careful not to type C-a C-4 when
           selecting window no. 4.  Use the empty bind command (as in "bind
           '^\'") to remove a key binding.

           readbuf [encoding] [filename]

           Reads the contents of the specified file into the paste buffer.
           You can tell screen the encoding of the file via the -e option.
           If no file is specified, the screen-exchange filename is used.
           See also "bufferfile" command.

           readreg [encoding] [register [

           Does one of two things, dependent on number of arguments: with
           zero or one arguments it it duplicates the paste buffer contents
           into the register specified or entered at the prompt. With two
           arguments it reads the contents of the named file into the
           register, just as readbuf reads the screen-exchange file into the
           paste buffer.  You can tell screen the encoding of the file via
           the -e option.  The following example will paste the system's
           password file into the screen window (using register p, where a



                                   - 41 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           copy remains):

                       C-a : readreg p /etc/passwd
           C-a : paste p

           redisplay

           Redisplay the current window. Needed to get a full redisplay when
           in partial redraw mode.

           register [-eencoding]key-string

           Save the specified string to the register key.  The encoding of
           the string can be specified via the -e option.  See also the
           "paste" command.

           remove

           Kill the current region. This is a no-op if there is only one
           region.

           removebuf

           Unlinks the screen-exchange file used by the commands "writebuf"
           and "readbuf".

           rendition bell | monitor | silence |

           Change the way screen renders the titles of windows that have
           monitor or bell flags set in caption or hardstatus or windowlist.
           See the "STRING ESCAPES" chapter for the syntax of the modifiers.
           The default for monitor is currently "=b " (bold, active colors),
           for bell "=ub " (underline, bold and active colors), and "=u "
           for silence.

           reset

           Reset the virtual terminal to its "power-on" values. Useful when
           strange settings (like scroll regions or graphics character set)
           are left over from an application.

           resize

           Resize the current region. The space will be removed from or
           added to the region below or if there's not enough space from the
           region above.

                resize +N
                     increase current region height by N





                                   - 42 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



                resize -N
                     decrease current region height by N

                resize  N
                     set current region height to N

                resize  =
                     make all windows equally high

                resize  max
                     maximize current region height

                resize  min
                     minimize current region height

           screen [-opts] [n] [cmd [args]|//group]

           Establish a new window.  The flow-control options (-f, -fn and
           -fa), title (a.k.a.) option (-t), login options (-l and -ln) ,
           terminal type option (-T <term>), the all-capability-flag (-a)
           and scrollback option (-h <num>) may be specified with each
           command.  The option (-M) turns monitoring on for this window.
           The option (-L) turns output logging on for this window.  If an
           optional number n in the range 0..MAXWIN-1 is given, the window
           number n is assigned to the newly created window (or, if this
           number is already in-use, the next available number).  If a
           command is specified after "screen", this command (with the given
           arguments) is started in the window; otherwise, a shell is
           created.  If //group is supplied, a container-type window is
           created in which other windows may be created inside it.

           Thus, if your ".screenrc" contains the lines

                       # example for .screenrc:
                       screen 1
                       screen -fn -t foobar -L 2 telnet foobar

           screen creates a shell window (in window #1) and a window with a
           TELNET connection to the machine foobar (with no flow-control
           using the title "foobar" in window #2) and will write a logfile
           ("screenlog.2") of the telnet session.  Note, that unlike
           previous versions of screen no additional default window is
           created when "screen" commands are included in your ".screenrc"
           file. When the initialization is completed, screen switches to
           the last window specified in your .screenrc file or, if none,
           opens a default window #0.

           Screen has built in some functionality of "cu" and "telnet".  See
           also chapter "WINDOW TYPES".





                                   - 43 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           scrollback num

           Set the size of the scrollback buffer for the current windows to
           num lines. The default scrollback is 100 lines.  See also the
           "defscrollback" command and use "info" to view the current
           setting. To access and use the contents in the scrollback buffer,
           use the "copy" command.

           select [WindowID]

           Switch to the window identified by WindowID.  This can be a
           prefix of a window title (alphanumeric window name) or a window
           number.  The parameter is optional and if omitted, you get
           prompted for an identifier. When a new window is established, the
           first available number is assigned to this window.  Thus, the
           first window can be activated by "select 0".  The number of
           windows is limited at compile-time by the MAXWIN configuration
           parameter (which defaults to 40).  There are two special
           WindowIDs, "-" selects the internal blank window and "." selects
           the current window. The latter is useful if used with screen's
           "-X" option.

           sessionname [name]

           Rename the current session. Note, that for "screen -list" the
           name shows up with the process-id prepended. If the argument
           "name" is omitted, the name of this session is displayed.
           Caution: The $STY environment variables will still reflect the
           old name in pre-existing shells. This may result in confusion.
           Use of this command is generally discouraged. Use the "-S"
           command-line option if you want to name a new session.  The
           default is constructed from the tty and host names.

           setenv [var [string]]

           Set the environment variable var to value string.  If only var is
           specified, the user will be prompted to enter a value.  If no
           parameters are specified, the user will be prompted for both
           variable and value. The environment is inherited by all
           subsequently forked shells.

           setsid [on|off]

           Normally screen uses different sessions and process groups for
           the windows. If setsid is turned off, this is not done anymore
           and all windows will be in the same process group as the screen
           backend process. This also breaks job-control, so be careful.
           The default is on, of course. This command is probably useful
           only in rare circumstances.





                                   - 44 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           shell command

           Set the command to be used to create a new shell.  This overrides
           the value of the environment variable $SHELL.  This is useful if
           you'd like to run a tty-enhancer which is expecting to execute
           the program specified in $SHELL. If the command begins with a '-'
           character, the shell will be started as a login-shell. Typical
           shells do only minimal initialization when not started as a
           login-shell.  E.g. Bash will not read your "~/.bashrc" unless it
           is a login-shell.

           shelltitle title

           Set the title for all shells created during startup or by the C-A
           C-c command.  For details about what a title is, see the
           discussion entitled "TITLES (naming windows)".

           silence [on|off|sec]

           Toggles silence monitoring of windows.  When silence is turned on
           and an affected window is switched into the background, you will
           receive the silence notification message in the status line after
           a specified period of inactivity (silence). The default timeout
           can be changed with the `silencewait' command or by specifying a
           number of seconds instead of `on' or `off'.  Silence is initially
           off for all windows.

           silencewait sec

           Define the time that all windows monitored for silence should
           wait before displaying a message. Default 30 seconds.

           sleep num

           This command will pause the execution of a .screenrc file for num
           seconds.  Keyboard activity will end the sleep.  It may be used
           to give users a chance to read the messages output by "echo".

           slowpaste msec

           Define the speed at which text is inserted into the current
           window by the paste ("C-a ]") command. If the slowpaste value is
           nonzero text is written character by character.  screen will make
           a pause of msec milliseconds after each single character write to
           allow the application to process its input. Only use slowpaste if
           your underlying system exposes flow control problems while
           pasting large amounts of text.

           sort





                                   - 45 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           Sort the windows in alphabetical order of the window tiles.

           source file

           Read and execute commands from file file. Source commands may be
           nested to a maximum recursion level of ten. If file is not an
           absolute path and screen is already processing a source command,
           the parent directory of the running source command file is used
           to search for the new command file before screen's current
           directory.

           Note that termcap/terminfo/termcapinfo commands only work at
           startup and reattach time, so they must be reached via the
           default screenrc files to have an effect.

           sorendition [attr[color]]

           This command is deprecated. See "rendition so" instead.

           split[-v]

           Split the current region into two new ones. All regions on the
           display are resized to make room for the new region. The blank
           window is displayed on the new region. Splits are made
           horizontally unless -v is used. Use the "remove" or the "only"
           command to delete regions. Use "focus" to toggle between regions.

           startup_message on|off

           Select whether you want to see the copyright notice during
           startup.  Default is `on', as you probably noticed.

           status [top|up|
                [left|right]

           The status window by default is in bottom-left corner. This
           command can move status messages to any corner of the screen. top
           is the same as up, down is the same as bottom.

           stuff [string]

           Stuff the string string in the input buffer of the current
           window.  This is like the "paste" command but with much less
           overhead.  Without a parameter, screen will prompt for a string
           to stuff.  You cannot paste large buffers with the "stuff"
           command. It is most useful for key bindings. See also "bindkey".

           su [username [password [

           Substitute the user of a display. The command prompts for all
           parameters that are omitted. If passwords are specified as



                                   - 46 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           parameters, they have to be specified un-crypted. The first
           password is matched against the systems passwd database, the
           second password is matched against the screen password as set
           with the commands "acladd" or "password".  "Su" may be useful for
           the screen administrator to test multiuser setups.  When the
           identification fails, the user has access to the commands
           available for user nobody.  These are "detach", "license",
           "version", "help" and "displays".

           suspend

           Suspend screen.  The windows are in the `detached' state, while
           screen is suspended. This feature relies on the shell being able
           to do job control.

           term term

           In each window's environment screen opens, the $TERM variable is
           set to "screen" by default. But when no description for "screen"
           is installed in the local termcap or terminfo data base, you set
           $TERM to - say - "vt100". This won't do much harm, as screen is
           VT100/ANSI compatible.  The use of the "term" command is
           discouraged for non-default purpose.  That is, one may want to
           specify special $TERM settings (e.g. vt100) for the next "screen
           rlogin othermachine" command. Use the command "screen -T vt100
           rlogin othermachine" rather than setting and resetting the
           default.

           termcap term terminal-tweaks[window-tweaks]

           terminfo term terminal-tweaks[window-tweaks]

           termcapinfo term terminal-tweaks[window-tweaks]

           Use this command to modify your terminal's termcap entry without
           going through all the hassles involved in creating a custom
           termcap entry.  Plus, you can optionally customize the termcap
           generated for the windows.  You have to place these commands in
           one of the screenrc startup files, as they are meaningless once
           the terminal emulator is booted.

           If your system works uses the terminfo database rather than
           termcap, screen will understand the `terminfo' command, which has
           the same effects as the `termcap' command.  Two separate commands
           are provided, as there are subtle syntactic differences, e.g.
           when parameter interpolation (using `%') is required. Note that
           termcap names of the capabilities have to be used with the
           `terminfo' command.

           In many cases, where the arguments are valid in both terminfo and
           termcap syntax, you can use the command `termcapinfo', which is



                                   - 47 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           just a shorthand for a pair of `termcap' and `terminfo' commands
           with identical arguments.

           The first argument specifies which terminal(s) should be affected
           by this definition.  You can specify multiple terminal names by
           separating them with `|'s.  Use `*' to match all terminals and
           `vt*' to match all terminals that begin with "vt".

           Each tweak argument contains one or more termcap defines
           (separated by `:'s) to be inserted at the start of the
           appropriate termcap entry, enhancing it or overriding existing
           values.  The first tweak modifies your terminal's termcap, and
           contains definitions that your terminal uses to perform certain
           functions.  Specify a null string to leave this unchanged (e.g.
           '').  The second (optional) tweak modifies all the window
           termcaps, and should contain definitions that screen understands
           (see the "VIRTUAL TERMINAL" section).

           Some examples:

                termcap xterm*  LP:hs@

           Informs screen that all terminals that begin with `xterm' have
           firm auto-margins that allow the last position on the screen to
           be updated (LP), but they don't really have a status line (no
           'hs' - append `@' to turn entries off).  Note that we assume `LP'
           for all terminal names that start with "vt", but only if you
           don't specify a termcap command for that terminal.
                termcap vt*  LP

           termcap vt102|vt220  Z0=\E[?3h:Z1=\E[?3l

           Specifies the firm-margined `LP' capability for all terminals
           that begin with `vt', and the second line will also add the
           escape-sequences to switch into (Z0) and back out of (Z1) 132-
           character-per-line mode if this is a VT102 or VT220.  (You must
           specify Z0 and Z1 in your termcap to use the width-changing
           commands.)

                termcap vt100  ""  l0=PF1:l1=PF2:l2=PF3:l3=PF4

           This leaves your vt100 termcap alone and adds the function key
           labels to each window's termcap entry.

                termcap h19|z19  am@:im=\E@:ei=\EO  dc=\E[P

           Takes a h19 or z19 termcap and turns off auto-margins (am@) and
           enables the insert mode (im) and end-insert (ei) capabilities
           (the `@' in the `im' string is after the `=', so it is part of
           the string).  Having the `im' and `ei' definitions put into your
           terminal's termcap will cause screen to automatically advertise



                                   - 48 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           the character-insert capability in each window's termcap.  Each
           window will also get the delete-character capability (dc) added
           to its termcap, which screen will translate into a line-update
           for the terminal (we're pretending it doesn't support character
           deletion).

           If you would like to fully specify each window's termcap entry,
           you should instead set the $SCREENCAP variable prior to running
           screen.  See the discussion on the "VIRTUAL TERMINAL" in this
           manual, and the termcap(5) man page for more information on
           termcap definitions.

           time [string]

           Uses the message line to display the time of day, the host name,
           and the load averages over 1, 5, and 15 minutes (if this is
           available on your system).  For window specific information, use
           "info".

           If a string is specified, it changes the format of the time
           report like it is described in the "STRING ESCAPES" chapter.
           Screen uses a default of "%c:%s %M %d %H%? %l%?".

           title [windowtitle]

           Set the name of the current window to windowtitle. If no name is
           specified, screen prompts for one. This command was known as
           `aka' in previous releases.

           truecolor [on|off]

           Enables truecolor support. Currently autodetection of truecolor
           support cannot be done reliably, as such it's left to user to
           enable. Default is off.  Known terminals that may support it are:
           iTerm2, Konsole, st.  Xterm includes support for truecolor
           escapes but converts them back to indexed 256 color space.

           unbindall

           Unbind all the bindings. This can be useful when screen is used
           solely for its detaching abilities, such as when letting a
           console application run as a daemon. If, for some reason, it is
           necessary to bind commands after this, use 'screen -X'.

           unsetenv var

           Unset an environment variable.

           utf8 [on|off[





                                   - 49 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           Change the encoding used in the current window. If utf8 is
           enabled, the strings sent to the window will be UTF-8 encoded and
           vice versa. Omitting the parameter toggles the setting. If a
           second parameter is given, the display's encoding is also changed
           (this should rather be done with screen's "-U" option).  See also
           "defutf8", which changes the default setting of a new window.

           vbell [on|off]

           Sets the visual bell setting for this window. Omitting the
           parameter toggles the setting. If vbell is switched on, but your
           terminal does not support a visual bell, a `vbell-message' is
           displayed in the status line when the bell character (^G) is
           received.  Visual bell support of a terminal is defined by the
           termcap variable `vb' (terminfo: 'flash').

           Per default, vbell is off, thus the audible bell is used. See
           also `bell_msg'.

           vbell_msg [message]

           Sets the visual bell message. message is printed to the status
           line if the window receives a bell character (^G), vbell is set
           to "on", but the terminal does not support a visual bell.  The
           default message is "Wuff, Wuff!!".  Without a parameter, the
           current message is shown.

           vbellwait sec

           Define a delay in seconds after each display of screen's visual
           bell message. The default is 1 second.

           verbose [on|off]

           If verbose is switched on, the command name is echoed, whenever a
           window is created (or resurrected from zombie state). Default is
           off.  Without a parameter, the current setting is shown.

           version

           Print the current version and the compile date in the status
           line.

           wall message

           Write a message to all displays. The message will appear in the
           terminal's status line.

           width [-w|-d] [





                                   - 50 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           Toggle the window width between 80 and 132 columns or set it to
           cols columns if an argument is specified. This requires a capable
           terminal and the termcap entries "Z0" and "Z1".  See the
           "termcap" command for more information. You can also specify a
           new height if you want to change both values.  The -w option
           tells screen to leave the display size unchanged and just set the
           window size, -d vice versa.

           windowlist [-b] [-m] [

           windowlist string [string]

           windowlist title [title]

           Display all windows in a table for visual window selection.  If
           screen was in a window group, screen will back out of the group
           and then display the windows in that group.  If the -b option is
           given, screen will switch to the blank window before presenting
           the list, so that the current window is also selectable.  The -m
           option changes the order of the windows, instead of sorting by
           window numbers screen uses its internal most-recently-used list.
           The -g option will show the windows inside any groups in that
           level and downwards.

           The following keys are used to navigate in "windowlist":

           allbox tab(@); l l.  k, C-p, or up@Move up one line.  j, C-n, or
           down@Move down one line.  C-g or escape@Exit windowlist.  C-a or
           home@Move to the first line.  C-e or end@Move to the last line.
           C-u or C-d@Move one half page up or down.  C-b or C-f@Move one
           full page up or down.  0..9@Using the number keys, move to the
           selected line.  mouseclick@T{ Move to the selected line.
           Available when "mousetrack" is set to "on" T} /@Search.  n@Repeat
           search in the forward direction.  N@Repeat search in the backward
           direction.  m@Toggle MRU.  g@Toggle group nesting.  a@All window
           view.  C-h or backspace@Back out the group.  ,@Switch numbers
           with the previous window.  K@Kill that window.  space or
           enter@Select that window.

           The table format can be changed with the string and title option,
           the title is displayed as table heading, while the lines are made
           by using the string setting. The default setting is "Num
           Name%=Flags" for the title and "%3n %t%=%f" for the lines.  See
           the "STRING ESCAPES" chapter for more codes (e.g. color
           settings).

           "Windowlist" needs a region size of at least 10 characters wide
           and 6 characters high in order to display.

           windows [ string ]




                                   - 51 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           Uses the message line to display a list of all the windows.  Each
           window is listed by number with the name of process that has been
           started in the window (or its title); the current window is
           marked with a `*'; the previous window is marked with a `-'; all
           the windows that are "logged in" are marked with a `$'; a
           background window that has received a bell is marked with a `!';
           a background window that is being monitored and has had activity
           occur is marked with an `@'; a window which has output logging
           turned on is marked with `(L)'; windows occupied by other users
           are marked with `&'; windows in the zombie state are marked with
           `Z'.  If this list is too long to fit on the terminal's status
           line only the portion around the current window is displayed.
           The optional string parameter follows the "STRING ESCAPES"
           format.  If string parameter is passed, the output size is
           unlimited.  The default command without any parameter is limited
           to a size of 1024 bytes.

           wrap [on|off]

           Sets the line-wrap setting for the current window.  When line-
           wrap is on, the second consecutive printable character output at
           the last column of a line will wrap to the start of the following
           line.  As an added feature, backspace (^H) will also wrap through
           the left margin to the previous line.  Default is `on'. Without
           any options, the state of wrap is toggled.

           writebuf [-e encoding

           Writes the contents of the paste buffer to the specified file, or
           the public accessible screen-exchange file if no filename is
           given. This is thought of as a primitive means of communication
           between screen users on the same host. If an encoding is
           specified the paste buffer is recoded on the fly to match the
           encoding.  The filename can be set with the bufferfile command
           and defaults to "/tmp/screen-exchange".

           writelock [on|off|auto]

           In addition to access control lists, not all users may be able to
           write to the same window at once. Per default, writelock is in
           `auto' mode and grants exclusive input permission to the user who
           is the first to switch to the particular window. When he leaves
           the window, other users may obtain the writelock (automatically).
           The writelock of the current window is disabled by the command
           "writelock off". If the user issues the command "writelock on" he
           keeps the exclusive write permission while switching to other
           windows.

           xoff





                                   - 52 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           xon

           Insert a CTRL-s / CTRL-q character to the stdin queue of the
           current window.

           zmodem [off|auto|catch|pass]

           zmodem sendcmd [string]

           zmodem recvcmd [string]

           Define zmodem support for screen. Screen understands two
           different modes when it detects a zmodem request: "pass" and
           "catch".  If the mode is set to "pass", screen will relay all
           data to the attacher until the end of the transmission is
           reached.  In "catch" mode screen acts as a zmodem endpoint and
           starts the corresponding rz/sz commands. If the mode is set to
           "auto", screen will use "catch" if the window is a tty (e.g. a
           serial line), otherwise it will use "pass".

           You can define the templates screen uses in "catch" mode via the
           second and the third form.

           Note also that this is an experimental feature.

           zombie [keys[onerror]]

           defzombie [keys]

           Per default screen windows are removed from the window list as
           soon as the windows process (e.g. shell) exits. When a string of
           two keys is specified to the zombie command, `dead' windows will
           remain in the list.  The kill command may be used to remove such
           a window. Pressing the first key in the dead window has the same
           effect. When pressing the second key, screen will attempt to
           resurrect the window. The process that was initially running in
           the window will be launched again. Calling zombie without
           parameters will clear the zombie setting, thus making windows
           disappear when their process exits.

           As the zombie-setting is manipulated globally for all windows,
           this command should only be called defzombie. Until we need this
           as a per window setting, the commands zombie and defzombie are
           synonymous.

           Optionally you can put the word "onerror" after the keys. This
           will cause screen to monitor exit status of the process running
           in the window. If it exits normally ('0'), the window disappears.
           Any other exit value causes the window to become a zombie.





                                   - 53 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



           zombie_timeout[seconds]

           Per default screen windows are removed from the window list as
           soon as the windows process (e.g. shell) exits. If zombie keys
           are defined (compare with above zombie command), it is possible
           to also set a timeout when screen tries to automatically
           reconnect a dead screen window.


 THE MESSAGE LINE
      Screen displays informational messages and other diagnostics in a
      message line.  While this line is distributed to appear at the bottom
      of the screen, it can be defined to appear at the top of the screen
      during compilation.  If your terminal has a status line defined in its
      termcap, screen will use this for displaying its messages, otherwise a
      line of the current screen will be temporarily overwritten and output
      will be momentarily interrupted. The message line is automatically
      removed after a few seconds delay, but it can also be removed early
      (on terminals without a status line) by beginning to type.

      The message line facility can be used by an application running in the
      current window by means of the ANSI Privacy message control sequence.
      For instance, from within the shell, try something like:

           echo '<esc>^Hello world from window '$WINDOW'<esc>\\'

      where '<esc>' is an escape, '^' is a literal up-arrow, and '\\' turns
      into a single backslash.


 WINDOW TYPES
      Screen provides three different window types. New windows are created
      with screen's screen command (see also the entry in chapter
      "CUSTOMIZATION"). The first parameter to the screen command defines
      which type of window is created. The different window types are all
      special cases of the normal type. They have been added in order to
      allow screen to be used efficiently as a console multiplexer with 100
      or more windows.


      +  The normal window contains a shell (default, if no parameter is
         given) or any other system command that could be executed from a
         shell (e.g. slogin, etc)


      +  If a tty (character special device) name (e.g. "/dev/ttya") is
         specified as the first parameter, then the window is directly
         connected to this device. This window type is similar to "screen cu
         -l /dev/ttya".  Read and write access is required on the device
         node, an exclusive open is attempted on the node to mark the
         connection line as busy.  An optional parameter is allowed



                                   - 54 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



         consisting of a comma separated list of flags in the notation used
         by stty(1):

         <baud_rate>
              Usually 300, 1200, 9600 or 19200. This affects transmission as
              well as receive speed.

         cs8 or cs7
              Specify the transmission of eight (or seven) bits per byte.

         ixon or -ixon
              Enables (or disables) software flow-control (CTRL-S/CTRL-Q)
              for sending data.

         ixoff or -ixoff
              Enables (or disables) software flow-control for receiving
              data.

         istrip or -istrip
              Clear (or keep) the eight bit in each received byte.

         You may want to specify as many of these options as applicable.
         Unspecified options cause the terminal driver to make up the
         parameter values of the connection.  These values are system
         dependent and may be in defaults or values saved from a previous
         connection.

         For tty windows, the info command shows some of the modem control
         lines in the status line. These may include `RTS', `CTS', 'DTR',
         `DSR', `CD' and more.  This depends on the available ioctl()'s and
         system header files as well as the on the physical capabilities of
         the serial board. Signals that are logical low (inactive) have
         their name preceded by an exclamation mark (!), otherwise the
         signal is logical high (active).  Signals not supported by the
         hardware but available to the ioctl() interface are usually shown
         low.

         When the CLOCAL status bit is true, the whole set of modem signals
         is placed inside curly braces ({ and }).  When the CRTSCTS or
         TIOCSOFTCAR bit is set, the signals `CTS' or `CD' are shown in
         parenthesis, respectively.

         For tty windows, the command break causes the Data transmission
         line (TxD) to go low for a specified period of time. This is
         expected to be interpreted as break signal on the other side.  No
         data is sent and no modem control line is changed when a break is
         issued.


      +  If the first parameter is "//telnet", the second parameter is
         expected to be a host name, and an optional third parameter may



                                   - 55 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



         specify a TCP port number (default decimal 23).  Screen will
         connect to a server listening on the remote host and use the telnet
         protocol to communicate with that server.

      For telnet windows, the command info shows details about the
      connection in square brackets ([ and ]) at the end of the status line.

           b    BINARY. The connection is in binary mode.

           e    ECHO. Local echo is disabled.

           c    SGA. The connection is in `character mode' (default: `line
                mode').

           t    TTYPE. The terminal type has been requested by the remote
                host.  Screen sends the name "screen" unless instructed
                otherwise (see also the command `term').

           w    NAWS. The remote site is notified about window size changes.

           f    LFLOW. The remote host will send flow control information.
                (Ignored at the moment.)

           Additional flags for debugging are x, t and n (XDISPLOC, TSPEED
           and NEWENV).

           For telnet windows, the command break sends the telnet code IAC
           BREAK (decimal 243) to the remote host.


           This window type is only available if screen was compiled with
           the ENABLE_TELNET option defined.



 STRING ESCAPES
      Screen provides an escape mechanism to insert information like the
      current time into messages or file names. The escape character is '%'
      with one exception: inside of a window's hardstatus '^%' ('^E') is
      used instead.

      Here is the full list of supported escapes:

      %    the escape character itself

      E    sets %? to true if the escape character has been pressed.

      f    flags of the window, see "windows" for meanings of the various
           flags





                                   - 56 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      F    sets %? to true if the window has the focus

      h    hardstatus of the window

      H    hostname of the system

      n    window number

      P    sets %? to true if the current region is in copy/paste mode

      S    session name

      s    window size

      t    window title

      u    all other users on this window

      w    all window numbers and names. With '-' qualifier: up to the
           current window; with '+' qualifier: starting with the window
           after the current one.

      W    all window numbers and names except the current one

      x    the executed command including arguments running in this windows

      X    the executed command without arguments running in this windows

      ?    the part to the next '%?' is displayed only if a '%' escape
           inside the part expands to a non-empty string

      :    else part of '%?'

      =    pad the string to the display's width (like TeX's hfill). If a
           number is specified, pad to the percentage of the window's width.
           A '0' qualifier tells screen to treat the number as absolute
           position.  You can specify to pad relative to the last absolute
           pad position by adding a '+' qualifier or to pad relative to the
           right margin by using '-'. The padding truncates the string if
           the specified position lies before the current position. Add the
           'L' qualifier to change this.

      <    same as '%=' but just do truncation, do not fill with spaces

      >    mark the current text position for the next truncation. When
           screen needs to do truncation, it tries to do it in a way that
           the marked position gets moved to the specified percentage of the
           output area. (The area starts from the last absolute pad position
           and ends with the position specified by the truncation operator.)
           The 'L' qualifier tells screen to mark the truncated parts with
           ''.



                                   - 57 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      {    attribute/color modifier string terminated by the next "}"

      `    Substitute with the output of a 'backtick' command. The length
           qualifier is misused to identify one of the commands.

      The 'c' and 'C' escape may be qualified with a '0' to make screen use
      zero instead of space as fill character. The '0' qualifier also makes
      the '=' escape use absolute positions. The 'n' and '=' escapes
      understand a length qualifier (e.g. '%3n'), 'D' and 'M' can be
      prefixed with 'L' to generate long names, 'w' and 'W' also show the
      window flags if 'L' is given.

      An attribute/color modifier is is used to change the attributes or the
      color settings. Its format is "[attribute modifier] [color
      description]". The attribute modifier must be prefixed by a change
      type indicator if it can be confused with a color description. The
      following change types are known:

      +    add the specified set to the current attributes

      -    remove the set from the current attributes

      !    invert the set in the current attributes

      =    change the current attributes to the specified set

      The attribute set can either be specified as a hexadecimal number or a
      combination of the following letters:

      d    dim
      u    underline
      b    bold
      r    reverse
      s    standout
      B    blinking

      Colors are coded either as a hexadecimal number or two letters
      specifying the desired background and foreground color (in that
      order). The following colors are known:

      k    black
      r    red
      g    green
      y    yellow
      b    blue
      m    magenta
      c    cyan
      w    white
      d    default color
      .    leave color unchanged




                                   - 58 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      The capitalized versions of the letter specify bright colors. You can
      also use the pseudo-color 'i' to set just the brightness and leave the
      color unchanged.
      A one digit/letter color description is treated as foreground or
      background color dependent on the current attributes: if reverse mode
      is set, the background color is changed instead of the foreground
      color.  If you don't like this, prefix the color with a ".". If you
      want the same behavior for two-letter color descriptions, also prefix
      them with a ".".
      As a special case, "%{-}" restores the attributes and colors that were
      set before the last change was made (i.e., pops one level of the
      color-change stack).

      Examples:

           set color to bright green

           use bold red

           clear all attributes, write in default color on yellow
           background.

      %-Lw%{= BW}%50>%n%f* %t%{-}%+Lw%<
           The available windows centered at the current window and
           truncated to the available width. The current window is displayed
           white on blue.  This can be used with "hardstatus
           alwayslastline".

      %?%F%{.R.}%?%3n %t%? [%h]%?
           The window number and title and the window's hardstatus, if one
           is set.  Also use a red background if this is the active focus.
           Useful for "caption string".

 FLOW-CONTROL
      Each window has a flow-control setting that determines how screen
      deals with the XON and XOFF characters (and perhaps the interrupt
      character).  When flow-control is turned off, screen ignores the XON
      and XOFF characters, which allows the user to send them to the current
      program by simply typing them (useful for the emacs editor, for
      instance).  The trade-off is that it will take longer for output from
      a "normal" program to pause in response to an XOFF.  With flow-control
      turned on, XON and XOFF characters are used to immediately pause the
      output of the current window.  You can still send these characters to
      the current program, but you must use the appropriate two-character
      screen commands (typically "C-a q" (xon) and "C-a s" (xoff)).  The
      xon/xoff commands are also useful for typing C-s and C-q past a
      terminal that intercepts these characters.

      Each window has an initial flow-control value set with either the -f
      option or the "defflow" .screenrc command. Per default the windows are
      set to automatic flow-switching.  It can then be toggled between the



                                   - 59 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      three states 'fixed on', 'fixed off' and 'automatic' interactively
      with the "flow" command bound to "C-a f".

      The automatic flow-switching mode deals with flow control using the
      TIOCPKT mode (like "rlogin" does). If the tty driver does not support
      TIOCPKT, screen tries to find out the right mode based on the current
      setting of the application keypad - when it is enabled, flow-control
      is turned off and visa versa.  Of course, you can still manipulate
      flow-control manually when needed.

      If you're running with flow-control enabled and find that pressing the
      interrupt key (usually C-c) does not interrupt the display until
      another 6-8 lines have scrolled by, try running screen with the
      "interrupt" option (add the "interrupt" flag to the "flow" command in
      your .screenrc, or use the -i command-line option).  This causes the
      output that screen has accumulated from the interrupted program to be
      flushed.  One disadvantage is that the virtual terminal's memory
      contains the non-flushed version of the output, which in rare cases
      can cause minor inaccuracies in the output.  For example, if you
      switch screens and return, or update the screen with "C-a l" you would
      see the version of the output you would have gotten without
      "interrupt" being on.  Also, you might need to turn off flow-control
      (or use auto-flow mode to turn it off automatically) when running a
      program that expects you to type the interrupt character as input, as
      it is possible to interrupt the output of the virtual terminal to your
      physical terminal when flow-control is enabled.  If this happens, a
      simple refresh of the screen with "C-a l" will restore it.  Give each
      mode a try, and use whichever mode you find more comfortable.



 TITLES (naming windows)
      You can customize each window's name in the window display (viewed
      with the "windows" command (C-a w)) by setting it with one of the
      title commands.  Normally the name displayed is the actual command
      name of the program created in the window.  However, it is sometimes
      useful to distinguish various programs of the same name or to change
      the name on-the-fly to reflect the current state of the window.

      The default name for all shell windows can be set with the
      "shelltitle" command in the .screenrc file, while all other windows
      are created with a "screen" command and thus can have their name set
      with the -t option.  Interactively, there is the title-string escape-
      sequence (<esc>kname<esc>\) and the "title" command (C-a A).  The
      former can be output from an application to control the window's name
      under software control, and the latter will prompt for a name when
      typed.  You can also bind pre-defined names to keys with the "title"
      command to set things quickly without prompting. Changing title bythis
      escape sequence can be controlled by defdynamictitle and dynamictitle
      commands.




                                   - 60 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      Finally, screen has a shell-specific heuristic that is enabled by
      setting the window's name to "search|name" and arranging to have a
      null title escape-sequence output as a part of your prompt.  The
      search portion specifies an end-of-prompt search string, while the
      name portion specifies the default shell name for the window.  If the
      name ends in a `:' screen will add what it believes to be the current
      command running in the window to the end of the window's shell name
      (e.g. "name:cmd").  Otherwise the current command name supersedes the
      shell name while it is running.

      Here's how it works:  you must modify your shell prompt to output a
      null title-escape-sequence (<esc>k<esc>\) as a part of your prompt.
      The last part of your prompt must be the same as the string you
      specified for the search portion of the title.  Once this is set up,
      screen will use the title-escape-sequence to clear the previous
      command name and get ready for the next command.  Then, when a newline
      is received from the shell, a search is made for the end of the
      prompt.  If found, it will grab the first word after the matched
      string and use it as the command name.  If the command name begins
      with either '!', '%', or '^' screen will use the first word on the
      following line (if found) in preference to the just-found name.  This
      helps csh users get better command names when using job control or
      history recall commands.

      Here's some .screenrc examples:

           screen -t top 2 nice top

      Adding this line to your .screenrc would start a nice-d version of the
      "top" command in window 2 named "top" rather than "nice".

                  shelltitle '> |csh'
                  screen 1

      These commands would start a shell with the given shelltitle.  The
      title specified is an auto-title that would expect the prompt and the
      typed command to look something like the following:

           /usr/joe/src/dir> trn

      (it looks after the '> ' for the command name).  The window status
      would show the name "trn" while the command was running, and revert to
      "csh" upon completion.

           bind R screen -t '% |root:' su

      Having this command in your .screenrc would bind the key sequence "C-a
      R" to the "su" command and give it an auto-title name of "root:".  For
      this auto-title to work, the screen could look something like this:

                  % !em



                                   - 61 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



                  emacs file.c

      Here the user typed the csh history command "!em" which ran the
      previously entered "emacs" command.  The window status would show
      "root:emacs" during the execution of the command, and revert to simply
      "root:" at its completion.

                  bind o title
                  bind E title ""
                  bind u title (unknown)

      The first binding doesn't have any arguments, so it would prompt you
      for a title. when you type "C-a o".  The second binding would clear an
      auto-title's current setting (C-a E).  The third binding would set the
      current window's title to "(unknown)" (C-a u).

      One thing to keep in mind when adding a null title-escape-sequence to
      your prompt is that some shells (like the csh) count all the non-
      control characters as part of the prompt's length.  If these invisible
      characters aren't a multiple of 8 then backspacing over a tab will
      result in an incorrect display.  One way to get around this is to use
      a prompt like this:

           set prompt='^[[0000m^[k^[\% '

      The escape-sequence "<esc>[0000m" not only normalizes the character
      attributes, but all the zeros round the length of the invisible
      characters up to 8.  Bash users will probably want to echo the escape
      sequence in the PROMPT_COMMAND:

           PROMPT_COMMAND='printf "\033k\033\134"'

      (I used "\134" to output a `\' because of a bug in bash v1.04).



 THE VIRTUAL TERMINAL
      Each window in a screen session emulates a VT100 terminal, with some
      extra functions added. The VT100 emulator is hard-coded, no other
      terminal types can be emulated.
      Usually screen tries to emulate as much of the VT100/ANSI standard as
      possible. But if your terminal lacks certain capabilities, the
      emulation may not be complete. In these cases screen has to tell the
      applications that some of the features are missing. This is no problem
      on machines using termcap, because screen can use the $TERMCAP
      variable to customize the standard screen termcap.

      But if you do a rlogin on another machine or your machine supports
      only terminfo this method fails. Because of this, screen offers a way
      to deal with these cases. Here is how it works:




                                   - 62 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      When screen tries to figure out a terminal name for itself, it first
      looks for an entry named "screen.<term>", where <term> is the contents
      of your $TERM variable.  If no such entry exists, screen tries
      "screen" (or "screen-w" if the terminal is wide (132 cols or more)).
      If even this entry cannot be found, "vt100" is used as a substitute.

      The idea is that if you have a terminal which doesn't support an
      important feature (e.g. delete char or clear to EOS) you can build a
      new termcap/terminfo entry for screen (named "screen.<dumbterm>") in
      which this capability has been disabled. If this entry is installed on
      your machines you are able to do a rlogin and still keep the correct
      termcap/terminfo entry.  The terminal name is put in the $TERM
      variable of all new windows.  Screen also sets the $TERMCAP variable
      reflecting the capabilities of the virtual terminal emulated. Notice
      that, however, on machines using the terminfo database this variable
      has no effect.  Furthermore, the variable $WINDOW is set to the window
      number of each window.

      The actual set of capabilities supported by the virtual terminal
      depends on the capabilities supported by the physical terminal.  If,
      for instance, the physical terminal does not support underscore mode,
      screen does not put the `us' and `ue' capabilities into the window's
      $TERMCAP variable, accordingly.  However, a minimum number of
      capabilities must be supported by a terminal in order to run screen;
      namely scrolling, clear screen, and direct cursor addressing (in
      addition, screen does not run on hardcopy terminals or on terminals
      that over-strike).

      Also, you can customize the $TERMCAP value used by screen by using the
      "termcap" .screenrc command, or by defining the variable $SCREENCAP
      prior to startup.  When the is latter defined, its value will be
      copied verbatim into each window's $TERMCAP variable.  This can either
      be the full terminal definition, or a filename where the terminal
      "screen" (and/or "screen-w") is defined.

      Note that screen honors the "terminfo" .screenrc command if the system
      uses the terminfo database rather than termcap.

      When the boolean `G0' capability is present in the termcap entry for
      the terminal on which screen has been called, the terminal emulation
      of screen supports multiple character sets.  This allows an
      application to make use of, for instance, the VT100 graphics character
      set or national character sets.  The following control functions from
      ISO 2022 are supported: lock shift G0 (SI), lock shift G1 (SO), lock
      shift G2, lock shift G3, single shift G2, and single shift G3.  When a
      virtual terminal is created or reset, the ASCII character set is
      designated as G0 through G3.  When the `G0' capability is present,
      screen evaluates the capabilities `S0', `E0', and `C0' if present.
      `S0' is the sequence the terminal uses to enable and start the
      graphics character set rather than SI. `E0' is the corresponding
      replacement for SO. `C0' gives a character by character translation



                                   - 63 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      string that is used during semi-graphics mode. This string is built
      like the `acsc' terminfo capability.

      When the `po' and `pf' capabilities are present in the terminal's
      termcap entry, applications running in a screen window can send output
      to the printer port of the terminal.  This allows a user to have an
      application in one window sending output to a printer connected to the
      terminal, while all other windows are still active (the printer port
      is enabled and disabled again for each chunk of output).  As a side-
      effect, programs running in different windows can send output to the
      printer simultaneously.  Data sent to the printer is not displayed in
      the window.  The info command displays a line starting `PRIN' while
      the printer is active.

      Screen maintains a hardstatus line for every window. If a window gets
      selected, the display's hardstatus will be updated to match the
      window's hardstatus line. If the display has no hardstatus the line
      will be displayed as a standard screen message.  The hardstatus line
      can be changed with the ANSI Application Program Command (APC):
      "ESC_<string>ESC\". As a convenience for xterm users the sequence
      "ESC]0..2;<string>^G" is also accepted.

      Some capabilities are only put into the $TERMCAP variable of the
      virtual terminal if they can be efficiently implemented by the
      physical terminal.  For instance, `dl' (delete line) is only put into
      the $TERMCAP variable if the terminal supports either delete line
      itself or scrolling regions. Note that this may provoke confusion,
      when the session is reattached on a different terminal, as the value
      of $TERMCAP cannot be modified by parent processes.

      The "alternate screen" capability is not enabled by default.  Set the
      altscreen .screenrc command to enable it.

      The following is a list of control sequences recognized by screen.
      "(V)" and "(A)" indicate VT100-specific and ANSI- or ISO-specific
      functions, respectively.

      ESC E                      Next Line

      ESC D                      Index

      ESC M                      Reverse Index

      ESC H                      Horizontal Tab Set

      ESC Z                      Send VT100 Identification String

      ESC 7                 (V)  Save Cursor and Attributes

      ESC 8                 (V)  Restore Cursor and Attributes




                                   - 64 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      ESC [s                (A)  Save Cursor and Attributes

      ESC [u                (A)  Restore Cursor and Attributes

      ESC c                      Reset to Initial State

      ESC g                      Visual Bell

      ESC Pn p                   Cursor Visibility (97801)

                                 Pn = 6                     Invisible

                                 Pn = 7                     Visible

      ESC =                 (V)  Application Keypad Mode

      ESC >                 (V)  Numeric Keypad Mode

      ESC # 8               (V)  Fill Screen with E's

      ESC \                 (A)  String Terminator

      ESC ^                 (A)  Privacy Message String (Message Line)

      ESC !                      Global Message String (Message Line)

      ESC k                      A.k.a. Definition String

      ESC P                 (A)  Device Control String.  Outputs a string
                                 directly to the host terminal without
                                 interpretation.

      ESC _                 (A)  Application Program Command (Hardstatus)

      ESC ] 0 ; string ^G   (A)  Operating System Command (Hardstatus, xterm
                                 title hack)

      ESC ] 83 ; cmd ^G     (A)  Execute screen command. This only works if
                                 multi-user support is compiled into screen.
                                 The pseudo-user ":window:" is used to check
                                 the access control list. Use "addacl
                                 :window: -rwx #?" to create a user with no
                                 rights and allow only the needed commands.

      Control-N             (A)  Lock Shift G1 (SO)

      Control-O             (A)  Lock Shift G0 (SI)

      ESC n                 (A)  Lock Shift G2





                                   - 65 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      ESC o                 (A)  Lock Shift G3

      ESC N                 (A)  Single Shift G2

      ESC O                 (A)  Single Shift G3

      ESC ( Pcs             (A)  Designate character set as G0

      ESC ) Pcs             (A)  Designate character set as G1

      ESC * Pcs             (A)  Designate character set as G2

      ESC + Pcs             (A)  Designate character set as G3

      ESC [ Pn ; Pn H            Direct Cursor Addressing

      ESC [ Pn ; Pn f            same as above

      ESC [ Pn J                 Erase in Display

                                 Pn = None or 0             From Cursor to
                                                            End of Screen

                                 Pn = 1                     From Beginning
                                                            of Screen to
                                                            Cursor

                                 Pn = 2                     Entire Screen

      ESC [ Pn K                 Erase in Line

                                 Pn = None or 0             From Cursor to
                                                            End of Line

                                 Pn = 1                     From Beginning
                                                            of Line to
                                                            Cursor

                                 Pn = 2                     Entire Line

      ESC [ Pn X                 Erase character

      ESC [ Pn A                 Cursor Up

      ESC [ Pn B                 Cursor Down

      ESC [ Pn C                 Cursor Right

      ESC [ Pn D                 Cursor Left





                                   - 66 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      ESC [ Pn E                 Cursor next line

      ESC [ Pn F                 Cursor previous line

      ESC [ Pn G                 Cursor horizontal position

      ESC [ Pn `                 same as above

      ESC [ Pn d                 Cursor vertical position

      ESC [ Ps ;; Ps m        Select Graphic Rendition

                                 Ps = None or 0             Default
                                                            Rendition

                                 Ps = 1                     Bold

                                 Ps = 2                (A)  Faint

                                 Ps = 3                (A)  Standout Mode
                                                            (ANSI:
                                                            Italicized)

                                 Ps = 4                     Underlined

                                 Ps = 5                     Blinking

                                 Ps = 7                     Negative Image

                                 Ps = 22               (A)  Normal Intensity

                                 Ps = 23               (A)  Standout Mode
                                                            off (ANSI:
                                                            Italicized off)

                                 Ps = 24               (A)  Not Underlined

                                 Ps = 25               (A)  Not Blinking

                                 Ps = 27               (A)  Positive Image

                                 Ps = 30               (A)  Foreground Black

                                 Ps = 31               (A)  Foreground Red

                                 Ps = 32               (A)  Foreground Green

                                 Ps = 33               (A)  Foreground
                                                            Yellow





                                   - 67 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



                                 Ps = 34               (A)  Foreground Blue

                                 Ps = 35               (A)  Foreground
                                                            Magenta

                                 Ps = 36               (A)  Foreground Cyan

                                 Ps = 37               (A)  Foreground White

                                 Ps = 39               (A)  Foreground
                                                            Default

                                 Ps = 40               (A)  Background Black

                                 Ps =

                                 Ps = 49               (A)  Background
                                                            Default

      ESC [ Pn g                 Tab Clear

                                 Pn = None or 0             Clear Tab at
                                                            Current Position

                                 Pn = 3                     Clear All Tabs

      ESC [ Pn ; Pn r       (V)  Set Scrolling Region

      ESC [ Pn I            (A)  Horizontal Tab

      ESC [ Pn Z            (A)  Backward Tab

      ESC [ Pn L            (A)  Insert Line

      ESC [ Pn M            (A)  Delete Line

      ESC [ Pn @            (A)  Insert Character

      ESC [ Pn P            (A)  Delete Character

      ESC [ Pn S                 Scroll Scrolling Region Up

      ESC [ Pn T                 Scroll Scrolling Region Down

      ESC [ Pn ^                 same as above

      ESC [ Ps ;; Ps h        Set Mode

      ESC [ Ps ;; Ps l        Reset Mode





                                   - 68 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



                                 Ps = 4                (A)  Insert Mode

                                 Ps = 20               (A)  Automatic
                                                            Linefeed Mode

                                 Ps = 34                    Normal Cursor
                                                            Visibility

                                 Ps = ?1               (V)  Application
                                                            Cursor Keys

                                 Ps = ?3               (V)  Change Terminal
                                                            Width to 132
                                                            columns

                                 Ps = ?5               (V)  Reverse Video

                                 Ps = ?6               (V)  Origin Mode

                                 Ps = ?7               (V)  Wrap Mode

                                 Ps = ?9                    X10 mouse
                                                            tracking

                                 Ps = ?25              (V)  Visible Cursor

                                 Ps = ?47                   Alternate Screen
                                                            (old xterm code)

                                 Ps = ?1000            (V)  VT200 mouse
                                                            tracking

                                 Ps = ?1047                 Alternate Screen
                                                            (new xterm code)

                                 Ps = ?1049                 Alternate Screen
                                                            (new xterm code)

      ESC [ 5 i             (A)  Start relay to printer (ANSI Media Copy)

      ESC [ 4 i             (A)  Stop relay to printer (ANSI Media Copy)

      ESC [ 8 ; Ph ; Pw t        Resize the window to `Ph' lines and `Pw'
                                 columns (SunView special)

      ESC [ c                    Send VT100 Identification String

      ESC [ x                    Send Terminal Parameter Report

      ESC [ > c                  Send VT220 Secondary Device Attributes
                                 String



                                   - 69 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      ESC [ 6 n                  Send Cursor Position Report



 INPUT TRANSLATION
      In order to do a full VT100 emulation screen has to detect that a
      sequence of characters in the input stream was generated by a keypress
      on the user's keyboard and insert the VT100 style escape sequence.
      Screen has a very flexible way of doing this by making it possible to
      map arbitrary commands on arbitrary sequences of characters. For
      standard VT100 emulation the command will always insert a string in
      the input buffer of the window (see also command stuff in the command
      table).  Because the sequences generated by a keypress can change
      after a reattach from a different terminal type, it is possible to
      bind commands to the termcap name of the keys.  Screen will insert the
      correct binding after each reattach. See the bindkey command for
      further details on the syntax and examples.

      Here is the table of the default key bindings. The fourth is what
      command is executed if the keyboard is switched into application mode.

      allbox; l l l l.  Key name              Termcap nameCommandApp mode
      Cursor up             ku\033[A\033OA Cursor
      down           kd\033[B\033OB Cursor right          kr\033[C\033OC
      Cursor left           kl\033[D\033OD Function key 0        k0\033[10~
      Function key 1        k1\033OP Function key 2        k2\033OQ Function
      key 3        k3\033OR Function key 4        k4\033OS Function key
      5        k5\033[15~ Function key 6        k6\033[17~ Function key
      7        k7\033[18~ Function key 8        k8\033[19~ Function key
      9        k9\033[20~ Function key 10       k;\033[21~ Function key
      11       F1\033[23~ Function key 12       F2\033[24~
      Home                  kh\033[1~ End                   kH\033[4~
      Insert                kI\033[2~ Delete                kD\033[3~ Page
      up               kP\033[5~ Page down             kN\033[6~ Keypad
      0              f00\033Op Keypad 1              f11\033Oq Keypad
      2              f22\033Or Keypad 3              f33\033Os Keypad
      4              f44\033Ot Keypad 5              f55\033Ou Keypad
      6              f66\033Ov Keypad 7              f77\033Ow Keypad
      8              f88\033Ox Keypad 9              f99\033Oy Keypad
      +              f++\033Ok Keypad -              f--\033Om Keypad
      *              f**\033Oj Keypad /              f//\033Oo Keypad
      =              fq=\033OX Keypad .              f..\033On Keypad
      ,              f,,\033Ol Keypad enter          fe\015\033OM


 SPECIAL TERMINAL CAPABILITIES
      The following table describes all terminal capabilities that are
      recognized by screen and are not in the termcap(5) manual.  You can
      place these capabilities in your termcap entries (in `/etc/termcap')
      or use them with the commands `termcap', `terminfo' and `termcapinfo'
      in your screenrc files. It is often not possible to place these



                                   - 70 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      capabilities in the terminfo database.

      LP   (bool)  Terminal has VT100 style margins (`magic margins'). Note
                   that this capability is obsolete because screen uses the
                   standard 'xn' instead.

      Z0   (str)   Change width to 132 columns.

      Z1   (str)   Change width to 80 columns.

      WS   (str)   Resize display. This capability has the desired width and
                   height as arguments. SunView(tm) example: '\E[8;%d;%dt'.

      NF   (bool)  Terminal doesn't need flow control. Send ^S and ^Q direct
                   to the application. Same as 'flow off'. The opposite of
                   this capability is 'nx'.

      G0   (bool)  Terminal can deal with ISO 2022 font selection sequences.

      S0   (str)   Switch charset 'G0' to the specified charset. Default is
                   '\E(%.'.

      E0   (str)   Switch charset 'G0' back to standard charset. Default is
                   '\E(B'.

      C0   (str)   Use the string as a conversion table for font '0'. See
                   the 'ac' capability for more details.

      CS   (str)   Switch cursor-keys to application mode.

      CE   (str)   Switch cursor-keys back to normal mode.

      AN   (bool)  Turn on autonuke. See the 'autonuke' command for more
                   details.

      OL   (num)   Set the output buffer limit. See the 'obuflimit' command
                   for more details.

      KJ   (str)   Set the encoding of the terminal. See the 'encoding'
                   command for valid encodings.

      AF   (str)   Change character foreground color in an ANSI conform way.
                   This capability will almost always be set to '\E[3%dm'
                   ('\E[3%p1%dm' on terminfo machines).

      AB   (str)   Same as 'AF', but change background color.

      AX   (bool)  Does understand ANSI set default fg/bg color (\E[39m /
                   \E[49m).





                                   - 71 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      XC   (str)   Describe a translation of characters to strings depending
                   on the current font. More details follow in the next
                   section.

      XT   (bool)  Terminal understands special xterm sequences (OSC, mouse
                   tracking).

      C8   (bool)  Terminal needs bold to display high-intensity colors
                   (e.g. Eterm).

      TF   (bool)  Add missing capabilities to the termcap/info entry. (Set
                   by default).


 CHARACTER TRANSLATION
      Screen has a powerful mechanism to translate characters to arbitrary
      strings depending on the current font and terminal type.  Use this
      feature if you want to work with a common standard character set (say
      ISO8851-latin1) even on terminals that scatter the more unusual
      characters over several national language font pages.

      Syntax:
          XC=<charset-mapping>{,,<charset-mapping>}
          <charset-mapping> := <designator><template>{,<mapping>}
          <mapping> := <char-to-be-mapped><template-arg>

      The things in braces may be repeated any number of times.

      A <charset-mapping> tells screen how to map characters in font
      <designator> ('B': Ascii, 'A': UK, 'K': German, etc.) to strings.
      Every <mapping> describes to what string a single character will be
      translated. A template mechanism is used, as most of the time the
      codes have a lot in common (for example strings to switch to and from
      another charset). Each occurrence of '%' in <template> gets
      substituted with the <template-arg> specified together with the
      character. If your strings are not similar at all, then use '%' as a
      template and place the full string in <template-arg>. A quoting
      mechanism was added to make it possible to use a real '%'. The '\'
      character quotes the special characters '\', '%', and ','.

      Here is an example:

          termcap hp700 'XC=B\E(K%\E(B,\304[,\326\\\\,\334]'

      This tells screen how to translate ISOlatin1 (charset 'B') upper case
      umlaut characters on a hp700 terminal that has a German charset.
      '\304' gets translated to '\E(K[\E(B' and so on.  Note that this line
      gets parsed *three* times before the internal lookup table is built,
      therefore a lot of quoting is needed to create a single '\'.

      Another extension was added to allow more emulation: If a mapping



                                   - 72 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      translates the unquoted '%' char, it will be sent to the terminal
      whenever screen switches to the corresponding <designator>. In this
      special case the template is assumed to be just '%' because the
      charset switch sequence and the character mappings normally haven't
      much in common.

      This example shows one use of the extension:

          termcap xterm 'XC=K%,%\E(B,[\304,\\\\\326,]\334'

      Here, a part of the German ('K') charset is emulated on an xterm.  If
      screen has to change to the 'K' charset, '\E(B' will be sent to the
      terminal, i.e. the ASCII charset is used instead. The template is just
      '%', so the mapping is straightforward: '[' to '\304', '\' to '\326',
      and ']' to '\334'.


 ENVIRONMENT
      COLUMNS        Number of columns on the terminal (overrides termcap
                     entry).
      HOME           Directory in which to look for .screenrc.
      LINES          Number of lines on the terminal (overrides termcap
                     entry).
      LOCKPRG        Screen lock program.
      NETHACKOPTIONS Turns on nethack option.
      PATH           Used for locating programs to run.
      SCREENCAP      For customizing a terminal's TERMCAP value.
      SCREENDIR      Alternate socket directory.
      SCREENRC       Alternate user screenrc file.
      SHELL          Default shell program for opening windows (default
                     "/bin/sh").  See also "shell" .screenrc command.
      STY            Alternate socket name.
      SYSSCREENRC    Alternate system screenrc file.
      TERM           Terminal name.
      TERMCAP        Terminal description.
      WINDOW         Window number of a window (at creation time).

 FILES
      /screen-4.?.??/etc/screenrc
      /screen-4.?.??/etc/etcscreenrc Examples in the screen distribution
                                        package for private and global
                                        initialization files.
      $SYSSCREENRC
      /usr/local/etc/screenrc           screen initialization commands
      $SCREENRC
      $HOME/.screenrc                   Read in after
                                        /usr/local/etc/screenrc
      $SCREENDIR/S-<login>
      /local/screens/S-<login>          Socket directories (default)
      /usr/tmp/screens/S-<login>        Alternate socket directories.




                                   - 73 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      <socket directory>/.termcap       Written by the "termcap" output
                                        function
      /usr/tmp/screens/screen-exchange  or
      /tmp/screen-exchange              screen `interprocess communication
                                        buffer'
      hardcopy.[0-9]                    Screen images created by the
                                        hardcopy function
      screenlog.[0-9]                   Output log files created by the log
                                        function
      /usr/lib/terminfo/?/*             or
      /etc/termcap                      Terminal capability databases
      /etc/utmp                         Login records
      $LOCKPRG                          Program that locks a terminal.


 SEE ALSO
      termcap(5), utmp(5), vi(1), captoinfo(1), tic(1)


 AUTHORS
      Originally created by Oliver Laumann. For a long time maintained and
      developed by Juergen Weigert, Michael Schroeder, Micah Cowan and
      Sadrul Habib Chowdhury. This latest version was produced by Amadeusz
      Slawinski <amade@asmblr.net> and Alexander Naumov
      <alexander_naumov@opensuse.org>.

 COPYLEFT
      Copyright (c) 2015-2017
           Juergen Weigert <jnweiger@immd4.informatik.uni-erlangen.de>
           Alexander Naumov <alexander_naumov@opensuse.org>
           Amadeusz Slawinski <amade@asmblr.net>
      Copyright (c) 2010-2015
           Juergen Weigert <jnweiger@immd4.informatik.uni-erlangen.de>
           Sadrul Habib Chowdhury <sadrul@users.sourceforge.net>
      Copyright (c) 2008, 2009
           Juergen Weigert <jnweiger@immd4.informatik.uni-erlangen.de>
           Michael Schroeder <mlschroe@immd4.informatik.uni-erlangen.de>
           Micah Cowan <micah@cowan.name>
           Sadrul Habib Chowdhury <sadrul@users.sourceforge.net>
      Copyright (C) 1993-2003
           Juergen Weigert <jnweiger@immd4.informatik.uni-erlangen.de>
           Michael Schroeder <mlschroe@immd4.informatik.uni-erlangen.de>
      Copyright (C) 1987 Oliver Laumann
      This program is free software; you can redistribute it and/or modify
      it under the terms of the GNU General Public License as published by
      the Free Software Foundation; either version 3, or (at your option)
      any later version.
      This program is distributed in the hope that it will be useful, but
      WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      General Public License for more details.



                                   - 74 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      You should have received a copy of the GNU General Public License
      along with this program (see the file COPYING); if not, write to the
      Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
      MA  02111-1307, USA

 CONTRIBUTORS
      Eric S. Raymond <esr@thyrsus.com>,
      Thomas Renninger <treen@suse.com>,
      Axel Beckert <abe@deuxchevaux.org>,
      Ken Beal <kbeal@amber.ssd.csd.harris.com>,
      Rudolf Koenig <rfkoenig@immd4.informatik.uni-erlangen.de>,
      Toerless Eckert <eckert@immd4.informatik.uni-erlangen.de>,
      Wayne Davison <davison@borland.com>,
      Patrick Wolfe <pat@kai.com, kailand!pat>,
      Bart Schaefer <schaefer@cse.ogi.edu>,
      Nathan Glasser <nathan@brokaw.lcs.mit.edu>,
      Larry W. Virden <lvirden@cas.org>,
      Howard Chu <hyc@hanauma.jpl.nasa.gov>,
      Tim MacKenzie <tym@dibbler.cs.monash.edu.au>,
      Markku Jarvinen <mta@{cc,cs,ee}.tut.fi>,
      Marc Boucher <marc@CAM.ORG>,
      Doug Siebert <dsiebert@isca.uiowa.edu>,
      Ken Stillson <stillson@tsfsrv.mitre.org>,
      Ian Frechett <frechett@spot.Colorado.EDU>,
      Brian Koehmstedt <bpk@gnu.ai.mit.edu>,
      Don Smith <djs6015@ultb.isc.rit.edu>,
      Frank van der Linden <vdlinden@fwi.uva.nl>,
      Martin Schweikert <schweik@cpp.ob.open.de>,
      David Vrona <dave@sashimi.lcu.com>,
      E. Tye McQueen <tye%spillman.UUCP@uunet.uu.net>,
      Matthew Green <mrg@eterna.com.au>,
      Christopher Williams <cgw@pobox.com>,
      Matt Mosley <mattm@access.digex.net>,
      Gregory Neil Shapiro <gshapiro@wpi.WPI.EDU>,
      Johannes Zellner <johannes@zellner.org>,
      Pablo Averbuj <pablo@averbuj.com>.

 AVAILABILITY
      The latest official release of screen available via anonymous ftp from
      ftp.gnu.org/gnu/screen/ or any other GNU distribution site. The home
      site of screen is savannah.gnu.org/projects/screen/. If you want to
      help, send a note to screen-devel@gnu.org.

 BUGS
      +  `dm' (delete mode) and `xs' are not handled correctly (they are
         ignored). `xn' is treated as a magic-margin indicator.

      +  Screen has no clue about double-high or double-wide characters. But
         this is the only area where vttest is allowed to fail.





                                   - 75 -      Formatted:  November 22, 2017






 SCREEN(1)                                                         SCREEN(1)
                                  Jul 2017



      +  It is not possible to change the environment variable $TERMCAP when
         reattaching under a different terminal type.

      +  The support of terminfo based systems is very limited. Adding extra
         capabilities to $TERMCAP may not have any effects.

      +  Screen does not make use of hardware tabs.

      +  Screen must be installed as set-uid with owner root on most systems
         in order to be able to correctly change the owner of the tty device
         file for each window.  Special permission may also be required to
         write the file "/etc/utmp".

      +  Entries in "/etc/utmp" are not removed when screen is killed with
         SIGKILL.  This will cause some programs (like "w" or "rwho") to
         advertise that a user is logged on who really isn't.

      +  Screen may give a strange warning when your tty has no utmp entry.

      +  When the modem line was hung up, screen may not automatically
         detach (or quit) unless the device driver is configured to send a
         HANGUP signal. To detach a screen session use the -D or -d command
         line option.

      +  If a password is set, the command line options -d and -D still
         detach a session without asking.

      +  Both "breaktype" and "defbreaktype" change the break generating
         method used by all terminal devices. The first should change a
         window specific setting, where the latter should change only the
         default for new windows.

      +  When attaching to a multiuser session, the user's .screenrc file is
         not sourced. Each user's personal settings have to be included in
         the .screenrc file from which the session is booted, or have to be
         changed manually.

      +  A weird imagination is most useful to gain full advantage of all
         the features.

      +  Send bug-reports, fixes, enhancements, t-shirts, money, beer &
         pizza to screen-devel@gnu.org.












                                   - 76 -      Formatted:  November 22, 2017