FEP(1L) SRA Distribution FEP(1L)
5 Aug 1988
NAME
fep - general purpose front end processor
SYNOPSIS
fep [-emacs|-vi] UNIX-command
DESCRIPTION
Fep is a general purpose front end processor applicable to most UNIX
commands that features vi(1)- or emacs(1)-like line editing and a
command history mechanism like that of csh(1).
Choice of editing style is made by selecting either the emacs mode or
the vi mode (named for the editors they emulate), specified either by
command line option or by setting a variable interactively or in the
start-up file or environment EDITMODE (see editmode variable).
The default key bindings are shown below for both edit modes. These
can be customized using the fep-bind command.
Emacs Bindings
Here follow the default key bindings for the emacs mode. Each
function name should be self-explanatory. The function names are
defined as similarly to Gosling's emacs as possible.
^@ mark
^A beginning-of-line
^B backward-character
^D delete-next-character
^E end-of-line
^F forward-character
^I insert-tab
^J new-line
^K kill-to-end-of-line
^L clear-screen
^M new-line
^N next-history
^P previous-history
^T previous-history
^Y yank-from-kill-buffer
^^ toggle-transparency
^X-^B show-bindings
^X-^H show-history
^X-^C terminate
^X-^D send-eof
^X-^L repaint
^X-^V view-buffer
^X-( start-script
^X-) end-script
esc-b backward-word
esc-B backward-word
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esc-d delete-next-word
esc-D delete-next-word
esc-f forward-word
esc-F forward-word
esc-h delete-previous-word
esc-H delete-previous-word
esc-l list-file-name
esc-L list-file-name
esc-esc expand-file-name
esc-? help
esc-_ invoke-shell
esc-< search-reverse
esc-> search-forward
esc-p insert-previous-history
esc-n insert-next-history
esc-. insert-current-history
/* Bindings inherited from the tty driver */
erase delete-previous-character
kill delete-line
rprnt reprint
werase delete-previous-word
lnext literal-next
Vi bindings
The vi mode has two sub-modes, the command mode and the text insert
mode. The commands of vi are emulated as correctly as possible. Here
is a list of the default key bindings of the vi mode that differ from
normal vi commands. The tty driver control characters are also
inherited in this mode.
n search-reverse
N search-forward
^A expand-file-name
^L list-file-name
^N next-history
^P previous-history
^R reprint
^^ toggle-transparency
^X-^B show-bindings
^X-^C terminate
^X-^D send-eof
^X-^H show-history
^X-^L repaint
^X-^X expand-file-name
^X-^V view-buffer
^X-l list-file-name
^X-L list-file-name
^X-? help
^X-( start-script
^X-) end-script
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Built-in commands
Fep has some built-in commands that are not passed to the child
process but understood and processed by fep itself. These commands
can be issued from the terminal or from the start-up file.
fep-bind function-name key-binding
Change key bindings. For example, to bind the function list-
file-name to the string "^X-^X", type the following:
fep-bind list-file-name "\^X\^X"
fep-alias
fep-alias name
fep-alias name string
The first form prints all aliases. The second form prints the
alias for name. The last form set the alias for name to
string.
You can refer arguments in command line by !^, !$, !*; they
stand for first, last, all arguments correspondingly.
To specify multiple commands in one alias, command should be
separated by semicolon (;) character. For example, next
description will allow you to execute fep-cd then pass cd
command to shell when input ``cd'' command.
fep-alias cd 'fep-cd !$;cd !$'
Note: Fep built-in functions must be defined before normal
commands.
If you use fep without auto-tty-fix, following alias could be
usefull.
if $command == sh
fep-alias more "fep-command more"
fep-alias vi "fep-command vi"
endif
fep-unalias list
Remove alias for each name in list.
fep-set variable = value
Set a variable of fep to some value.
fep-unset variable
Unset a variable.
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fep-cd [ directory ]
fep-chdir [ directory ]
Change directory. It sometimes happens that a child process
has changed directory, but fep is still in the old directory.
In such a case, neither list-file-name nor expand-file-name
will function as expected. This command allows you to change
fep's current working directory (default = home directory).
fep-pwd
Print fep's current working directory.
fep-history [ number of line ]
Show the history of commands under fep.
fep-echo arguments
Only print the arguments. Variable names can be used prefixed
by the "$" character.
fep-source file
Read the specified file and execute it. The contents of the
file are not sent to sub-processes.
fep-save-history [ number of lines to save ] file
Save the current history buffer in the specified file.
fep-read-history [ file ]
Read in the command history from the specified file. The
default file is the value of the history-file variable. This
file name is understood as a path relative to the home
directory. If you want to specify the name relative to the
current directory instead, prefix the path by "./".
fep-command command
fep-! command
Execute command.
quit-fep
Kill the sub-process and exit.
fep-suspend
Suspend fep itself. In the unlikely possibility that fep
falls into a dead-lock in which the sub-processes have stopped
but fep is still running, use this command to escape from the
situation.
fep-read-from-file file
fep-< file
Read data from specified file and send them to sub-process.
The sub-process will read the data from the file as if they
are typed at the keyboard.
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fep-read-from-command command
fep-<! command
Send output of specified command to sub-process.
fep-start-script [ script-file ]
fep-script [ script-file ]
Start to send input and output to a script file. If script-
file is specified, it is used. If not the value of the
variable script-file will be used.
fep-stop-script
Stop scripting.
fep-show-bind
Print current binding information.
fep-repaint [ line ]
Repaint last output from command to screen. ``line''
specifies number of lines to repaint (default is screenful
maximum). See also ``auto-repaint'' and ``clear-repaint''
variables.
Control structures
fep-if expression
fep-elseif expression
fep-else
fep-endif
Only four control structures are supported but that seems
enough. Expression allows only the two operators "==" and
"!=". Variables can be referenced by prefixing with the "$"
character.
Note: The "fep-" prefix of the built-in functions and the above
operators can be abbreviated in commands that fep executes from a
file.
Comment
Lines starting with the character "#" are ignored by fep. If fep
encounters a comment in interaction, it is sent to the sub-process.
In reading from a file, comments will merely be ignored.
Variables
Fep uses some variables.
alarm-on-eof default: off
If this variable is set AND the function send-eof is not bound
to the eof character AND the variable ignore-eof is not set,
an alarm message will be displayed once the first time eof is
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encountered on an empty line.
auto-repaint default: off
If this variable is set, fep automatically repaints the screen
after restarting.
auto-tty-fix default: on
If this variable is set, fep looks at the tty mode of the
sub-command, and if the tty mode has changed, fep fixes the
tty mode of standard out and sets the transparency flag
according to the mode. If this variable is not set, the
automatic tty mode check is not done, so you have to change
the tty mode and transparency explicitly using the toggle-
transparency function.
buffer default: 5120
Specifies command output buffer size. High-watermark used in
buffer management mechanism will be set 4/5 of this count.
clear-repaint default: off
If this variable is set, fep clears the screen before
repainting.
command default: command-name
Fep set this variable to the command name of the sub-process
when it starts up.
crt default: terminal size
If set, more message is shown during printing the key bindings
on each number of line specified by this variable.
delimiters default: SPACE & TAB
The contents of this variable are treated as delimiting
characters for file name expantion and file name list.
editmode default: emacs
This variable defines the mode for command line editing. Key
bindings will be set for the appropriate defaults when this
variable is changed. Fep first looks at the environment
variable EDITMODE, then looks at any command line arguments,
and finally reads in the .feprc start-up file.
expand-tilde default: on
Fep expands "~" to the real home directory name by the
expand-file-name function when this variable is set.
history default: 100
Fep maintains a history file of the length specified by this
variable.
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history-file default: .fephistory
Contains the name of the history file for reading from and
writing to. If the file described by this variable exists,
fep will read the file into the history buffer on start up and
then save the current session's history when it exits.
ignore-empty-line default: on
If this variable is set, empty command lines are not saved in
the history file.
ignore-eof default: off
Fep never worries about the eof character if this variable is
set.
ignore-same-line default: on
If this variable is set, command lines identical to the
previous command line are not saved to the history file.
ignore-same-line default: on
If this variable is set, command lines which is shorter than
this value are not saved to the history file.
noalias default: off
If set, command aliasing won't be done.
prompt default: see below
Fep outputs a prompt after executing built-in functions. The
default string is set to the NULL string, but there are some
default prompt strings for some common commands such as sh,
dbx, lpc, mail, sendmail -bt and calc. However, since fep
doesn't care about what program is running, the same prompt is
still output when you are executing bc from sh.
You can change the value of prompt and other variables in the
start-up file as follows:
if $command == sh
set prompt = "$ "
endif
savehist default: off
If savehist is set fep saves the number of history entries
specified by value of this variable in the file named in the
variable history-file on terminating.
script-file default: fepscript
This variable is used by the fep-start-script command and by
the start-script function.
shell default: /bin/sh
Describe the command name to be invoked by invoke-shell.
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showhist default: terminal size
This variable specifies the number of history lines to be
displayed by the show-history function.
tty-fix-bell default: off
If this variable is set, fep rings the bell when the tty mode
is changed.
Start-Up File
Fep executes the file ".feprc" in the home directory of the user if it
is found there when starting up. It looks for arguments on the
command line first, and only then reads the ".feprc" file, so the file
has higher priority.
Functions
abort Abort function
backward-Word Backward word (non-space)
backward-character Backward character
backward-word Backward word (alpha-numeric)
beginning-of-line Jump to beginning of line
clear-screen Clear screen
delete-line Delete whole line
delete-next-Word Delete next word (non-space)
delete-next-character Delete next character
delete-next-word Delete next word (alpha-numeric)
delete-previous-Word Delete previous word (non-space)
delete-previous-character Delete previous character
delete-previous-word Delete previous word (alpha-numeric)
delete-to-kill-buffer Delete resion to buffer
end-of-line Jump to end of line
end-script End script
expand-file-name Expand file name
fix-transparency Check tty and change transparency mode
forward-Word Forward word (non-space)
forward-character Forward character
forward-to-end-of-Word Forward to end of word (non-space)
forward-to-end-of-word Forward to end of word (alpha-numeric)
forward-word Forward word (alpha-numeric)
help Show help
ignore Ignore
insert-and-flush Insert the character and flush buffer
insert-tab Insert tab
invoke-shell Invoke shell process
kill-to-end-of-line Delete current position to eol
kill-to-top-of-line Delete tol to current position
list-file-name List file name
literal-next Treat next character as literal
mark Mark position
new-line Insert newline
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next-history Get next history
previous-history Get previous history
insert-next-history Insert next history
insert-previous-history Insert previous history
insert-current-history Insert current history
repaint Repaint screen
reprint Reprint line
search-forward Search forward last !history
search-reverse Search backward last !history
self-insert Insert the character
send-eof Send eof
show-bindings Show binding table
show-history Show history
start-script Start script
suspend Suspend fep
terminate Terminate fep
toggle-transparency Change transparency mode
vi-c Vi c? commands
vi-d Vi d? commands
vi-edit Vi edit commands
vi-ins-edit Vi insert mode
vi-motion Vi cursor motion commands
vi-new-line Vi new line
vi-num Vi prefix number
view-buffer View buffer
yank-from-kill-buffer Yank from kill buffer
Probably only the function name "toggle-transparency" is hard to
understand. This function is provided for entering non-line-oriented
tools from a line-oriented tool using fep. Assume a situation where
you are using sh(1) with fep, and then invoke vi(1). Since fep
intercepts all input for editing, vi cannot work correctly. You can
escape from this annoying situation using the "toggle-transparency"
function which is bound to the Control-^ key by default. Of course,
it is also necessary to return to the normal mode after exiting vi.
Note, however, that this tty mode fix can also be done automatically.
If the auto-tty-fix variable is set, fep looks at the tty mode of the
sub-command and fixes the tty mode of standard input accordingly.
OTHERS
Fep can handle SHIFT-JIS kanji code if compiled with the -DKANJI flag.
SEE ALSO
newcsh(1)
COPYRIGHT
Copyright (c) 1987, 1988 by Software Research Associates, Inc.
Distribution without fee is allowed as long as all copyright notices
are included.
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FEP(1L) SRA Distribution FEP(1L)
5 Aug 1988
AUTHOR
K. Utashiro
Software Research Associates, Inc., Japan.
UUCP: kddlab!srava.sra.junet!utashiro
ARPA: utashiro%sra.junet@uunet.uu.net
JUNET: utashiro@sra.junet
FILES
~/.feprc, ./.feprc start-up file
~/.fephistory default history file
./fepscript default script file
BUGS
While working on the program the author sometimes lost his mind,
whereupon so did the program.
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