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 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



 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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      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)
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      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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                                  Feb 2020



      -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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                                  Feb 2020



      -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 an 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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                                  Feb 2020



            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)
                                  Feb 2020



      -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 trailing
      commas in boxes with multiple keystroke entries are separators, not
      part of the bindings.  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,



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                                  Feb 2020



      C-a C-c T};(screen);T{ Create a new window with a shell and switch to
      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} _ 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



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      stdin queue of the current window. T} _ T{ C-a {,
      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.




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      The following commands are available:

      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



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      "none" is used for groupname.  If the second parameter is omitted all
      groups the user is in are listed.

      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





                                   - 11 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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
      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"




                                   - 12 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



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

           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]




                                   - 13 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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
      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.




                                   - 14 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



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



                                   - 15 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



              bindkey -t foo stuff barfoo

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

              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]





                                   - 16 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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 ]
                  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



                                   - 17 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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.

      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]





                                   - 18 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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.

      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:

      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.




                                   - 19 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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.

           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:




                                   - 20 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



           "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".

      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





                                   - 21 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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'.

      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



                                   - 22 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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

      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'.



                                   - 23 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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'.

      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





                                   - 24 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



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

      detach [-h]

      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:

      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".



                                   - 25 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



           (F) Number of the window

           (G) Name/title of window

           (H) Whether the window is shared

           (I) Window permissions. Made up of three characters.  allbox
           tab(:); csssss cs cs cs l l l l l l.  Window permissions
           indicators 1st character:2nd character:3rd character -:no
           read:-:no write:-:no execute r:read:w:write:x:execute ::W:own
           wlock:: lsssss l l l l l l.  Indicators of permissions suppressed
           by a foreign wlock R:read only:.:no write::

           "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

      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



                                   - 26 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



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




                                   - 27 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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 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;



                                   - 28 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



                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 [next|prev|up|down|left|right|top|bottom]

      Move the input focus to the next region. This is done in a cyclic way
      so that the top left region is selected after the bottom right one. If
      no option is given it defaults to `next'. The next region to be
      selected is determined by how the regions are layered.  Normally, the
      next region in the same layer would be selected.  However, if that
      next region contains one or more layers, the first region in the
      highest layer is selected first. If you are at the last region of the
      current layer, `next' will move the focus to the next region in the
      lower layer (if there is a lower layer).  `Prev' cycles in the
      opposite order. See "split" for more information about layers.

      The rest of the options (`up', `down', `left', `right', `top', and
      `bottom') are more indifferent to layers. The option `up' will move
      the focus upward to the region that is touching the upper left corner
      of the current region.  `Down' will move downward to the region that
      is touching the lower left corner of the current region. The option
      `left' will move the focus leftward to the region that is touching the
      upper left corner of the current region, while `right' will move
      rightward to the region that is touching the upper right corner of the
      current region. Moving left from a left most region or moving right
      from a right most region will result in no action.

      The option `top' will move the focus to the very first region in the
      upper list corner of the screen, and `bottom' will move to the region
      in the bottom right corner of the screen. Moving up from a top most



                                   - 29 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      region or moving down from a bottom most region will result in no
      action.

      Useful bindings are (h, j, k, and l as in vi)
          bind h focus left
          bind j focus down
          bind k focus up
          bind l focus right
          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 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



                                   - 30 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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'.

      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



                                   - 31 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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 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): allbox tab(@); l l.  +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'



                                   - 32 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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 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



                                   - 33 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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.

      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.



                                   - 34 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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 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



                                   - 35 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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.

      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]





                                   - 36 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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 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.





                                   - 37 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      monitor [on|off]

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



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 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      nonblock [on|off|numsecs

      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 attempts by another user



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                                  Feb 2020



      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.

      prev

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




                                   - 40 -      Formatted:  February 25, 2020






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                                  Feb 2020



      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 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 copy remains):

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

      redisplay




                                   - 41 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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
           [-h|-v|-b [[+|-] n[%] |=|max|min

      Resize the current region. The space will be removed from or added to
      the surrounding regions depending on the order of the splits.  The
      available options for resizing are `-h'(horizontal), `-v'(vertical),
      `-b'(both), `-l'(local to layer), and `-p'(perpendicular). Horizontal
      resizes will add or remove width to a region, vertical will add or
      remove height, and both will add or remove size from both dimensions.
      Local and perpendicular are similar to horizontal and vertical, but
      they take in account of how a region was split.  If a region's last
      split was horizontal, a local resize will work like a vertical resize.
      If a region's last split was vertical, a local resize will work like a
      horizontal resize. Perpendicular resizes work in opposite of local
      resizes. If no option is specified, local is the default.

      The amount of lines to add or remove can be expressed a couple of
      different ways. By specifying a number n by itself will resize the
      region by that absolute amount. You can specify a relative amount by



                                   - 42 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      prefixing a plus `+' or minus `-' to the amount, such as adding +n
      lines or removing -n lines. Resizing can also be expressed as an
      absolute or relative percentage by postfixing a percent sign `%'.
      Using zero `0' is a synonym for `min' and using an underscore `_' is a
      synonym for `max'.

      Some examples are:

      resize +N
           increase current region by N

      resize -N
           decrease current region by N

      resize  N
           set current region to N

      resize 20%
           set current region to 20% of original size

      resize +20%
           increase current region by 20%

      resize -b =
           make all windows equally

      resize  max
           maximize current region

      resize  min
           minimize current region

      Without any arguments, screen will prompt for how you would like to
      resize the current region.

      See "focusminsize" if you want to restrict the minimun size a region
      can have.

      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



                                   - 43 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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".

      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.



                                   - 44 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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.

      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



                                   - 45 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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

      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 in the new region. The default is to create a horizontal
      split, putting the new regions on the top and bottom of each other.
      Using `-v' will create a vertical split, causing the new regions to
      appear side by side of each other.  Use the "remove" or the "only"
      command to delete regions.  Use "focus" to toggle between regions.

      When a region is split opposite of how it was previously split (that
      is, vertical then horizontal or horizontal then vertical), a new layer
      is created. The layer is used to group together the regions that are
      split the same. Normally, as a user, you should not see nor have to
      worry about layers, but they will affect how some commands ("focus"
      and "resize") behave.

      With this current implementation of screen, scrolling data will appear
      much slower in a vertically split region than one that is not. This



                                   - 46 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      should be taken into consideration if you need to use system commands
      such as "cat" or "tail -f".

      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 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.



                                   - 47 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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 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 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




                                   - 48 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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 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.

      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



                                   - 49 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      bind commands after this, use 'screen -X'.

      unsetenv var

      Unset an environment variable.

      utf8 [on|off[

      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




                                   - 50 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



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

      width [-w|-d] [

      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":

      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.




                                   - 51 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      windows [ string ]

      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

      xon




                                   - 52 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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]]

      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 probably be called defzombie, but it isn't.

      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.

      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.





                                   - 53 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



 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
         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.



                                   - 54 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



         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
         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.





                                   - 55 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



           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

      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




                                   - 56 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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
           '...'.

      {    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



                                   - 57 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      prefixed with 'L' to generate long names, 'w' and 'W' also show the
      window flags if 'L' is given.

      An attribute/color modifier 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

      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 ".".



                                   - 58 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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
      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.



                                   - 59 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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 by
      this escape sequence can be controlled by defdynamictitle and
      dynamictitle commands.

      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.




                                   - 60 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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
                  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)



                                   - 61 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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:

      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



                                   - 62 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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 latter is 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
      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



                                   - 63 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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

      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)





                                   - 64 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



                                 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

      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





                                   - 65 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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

      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





                                   - 66 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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

                                 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



                                   - 67 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



                                 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

                                 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



                                   - 68 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



                                                            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

      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



                                   - 69 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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
      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'.



                                   - 70 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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).

      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).





                                   - 71 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



 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
      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',



                                   - 72 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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.
      <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.





                                   - 73 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



 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. Since 2015 maintained and developed by
      Amadeusz Slawinski <amade@asmblr.net> and Alexander Naumov
      <alexander_naumov@opensuse.org>.

 COPYLEFT
      Copyright (c) 2018-2020
           Alexander Naumov <alexander_naumov@opensuse.org>
           Amadeusz Slawinski <amade@asmblr.net>
      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.
      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
      Maarten ter Huurne <maarten@treewalker.org>,
      Jussi Kukkonen <jussi.kukkonen@intel.com>,
      Eric S. Raymond <esr@thyrsus.com>,
      Thomas Renninger <treen@suse.com>,
      Axel Beckert <abe@deuxchevaux.org>,
      Ken Beal <kbeal@amber.ssd.csd.harris.com>,



                                   - 74 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



      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.

      +  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



                                   - 75 -      Formatted:  February 25, 2020






 SCREEN(1)                                                         SCREEN(1)
                                  Feb 2020



         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:  February 25, 2020