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ledit

NAME

ledit - line editor, version 2.00

SYNOPSIS

ledit [-h file] [-x] [-t] [-l length] [-a | -u] [command options]

DESCRIPTION

The command ledit allows to edit lines one by one when running an interactive command. When typing a line, some keys with control or meta are interpreted: it is possible to insert characters in the middle of the line, go to the beginning or the end of the line, get a previous line, search for a line with a pattern, etc.

OPTIONS

The options are:

-h file

Save the lines typed (history) in file. The default is to have them only in memory (so, they are lost at the end of the program).

-x

Extend the history file (given in option "-h") if it already exists. The default is to truncate the history file.

-t

Display the sequences generated by the keys (for debugging).

-v

Print ledit version and exit.

-l length

Tells that length is the maximum line length displayed. If the line edited is longer than this length, the line scrolls horizontally, while editing. The default value is 70.

-a

Ascii encoding: characters whose code is greater than 128 are displayed with a backslash followed by their code.

-u

Unicode encoding: the terminal must have been set in unicode mode. See commands unicode_start and unicode_stop.

command options

Runs the command command and its possible options. This must be the last option of ledit. The default value is "cat".

KEYS BINDINGS

When ledit starts, some default key bindings are defined. The can be completed with a "leditrc" file. See the section LEDITRC.

In the following lines, the caret sign "^" means "control" and the sequence "M-" means "meta" (either with the "meta" prefix, or by pressing the "escape" key before). Examples:

^a

press the "control" key, then press "a", then release "a", then release "control".

M-a

press the "meta" key, then press "a", then release "a", then release "meta", or: press and release the "escape" key, then press and release "a" (the manipulation with "meta" may not work in some systems: in this case, use the manipulation with "escape").

The editing commands are:

       ^a   : beginning of line
       ^e   : end of line
       ^f   : forward char
       ^b   : backward char
       M-f  : forward word
       M-b  : backard word
       ^p   : previous line in history
       ^n   : next line in history
       M-<  : first line in history
       M->  : last line in history
       ^r   : reverse search in history (see below)
       ^d   : delete char (or EOF if the line is empty)
       ^h   : (or backspace) backward delete char
       ^t   : transpose chars
       M-c  : capitalize word
       M-u  : upcase word
       M-l  : downcase word
       M-d  : kill word
       M-^h : (or M-del or M-backspace) backward kill word
       ^q   : insert next char
       M-/  : expand abbreviation
       ^k   : cut until end of line
       ^y   : paste
       ^u   : line discard
       ^l   : redraw current line
       ^g   : abort prefix
       ^c   : interrupt
       ^z   : suspend
       ^\   : quit
       return : send line
       ^x     : send line and show next history line
       other  : insert char
 

The arrow keys can be used, providing your keyword returns standard key sequences:

       up arrow    : previous line in history
       down arrow  : next line in history
       right arrow : forward char
       left arrow  : backward char
 

Other keys:

       home        : beginning of line
       end         : end of line
       delete      : delete char
       page up     : previous line in history
       page down   : next line in history
       shift home  : beginning of history
       shift end   : end of history
 

REVERSE SEARCH

The reverse search in incremental, i.e. ledit backward searchs in the history a line holding the characters typed. If you type "a", its search the first line before the current line holding an "a" and displays it. If you then type a "b", its search a line holding "ab", and so on. If you type ^h (or backspace), it returns to the previous line found. To cancel the search, type ^g. To find another line before holding the same string, type ^r. To stop the editing and display the current line found, type "escape" (other commands of the normal editing, different from ^h, ^g, and ^r stop the editing too).

Summary of reverse search commands:

       ^g  : abort search
       ^r  : search previous same pattern
       ^h  : (or backspace) search without the last char
       del : search without the last char
       any other command : stop search and show the line found
 

LEDITRC

If the environment variable LEDITRC is set, it contains the name of the leditrc file. Otherwise it is the file named ".leditrc" in user's home directory. When starting, ledit reads this file, if it exists, to modify or complete the default bindings. If this file is changed while reading lines, it is read again to take the new file into account.

Bindings lines are the ones which start with a string defining the key sequence and follow with a colon and a binding. A binding is either a string or a command. The other lines are ignored For example,the line:

     "\C-a": beginning-of-line
 

binds the sequence "control-a" to the command "beginning-of-line".

The key sequence may contain the specific meta-sequences:

     \C-   followed by a key: "control" of this key
     \M-   followed by a key: "meta" of this key
     \e    the "escape" key
     \nnn  where nnn is one, two, or three octal digits, or:
     \xnn  where nn is one or two hexadecimal digits:
             the binary representation of a byte
     \a    bell = \C-g
     \b    backspace = \C-h
     \d    delete = \277
     \f    form feed = \C-l
     \n    newline = \C-j
     \r    carriage return = \C-m
     \t    tabulation = \C-i
     \v    vertical tabulation = \C-k
 

The commands are:

   abort: do nothing
   accept-line: send the current line
   backward-char: move the cursor to the previous character
   backward-delete-char: delete the previous character
   backward-kill-word: delete the previous word
   backward-word: move the cursor before the previous word
   beginning-of-history: display the first line of the history
   beginning-of-line: move the cursor at the beginning of the line
   capitalize-word: uppercase the first char and lowercase the rest
   delete-char: delete the character under the cursor
   delete-char-or-end-of-file: same but eof if no character in the line
   downcase-word: lowercase whole word
   end-of-history: display the last line of the history
   end-of-line: move the cursor to the end of the line
   expand-abbrev: try to complete the word by looking at the history
   forward-char: move the cursor after the next word
   forward-word: move the cursor to the next character
   interrupt: interrupt command (send control-C)
   kill-line: delete from the cursor to the end and save in buffer
   kill-word: delete the next word
   next-history: display the next line of the history
   operate-and-get-next: send line and display the next history line
   previous-history: display the previous line of the history
   quit: quit ledit
   quoted-insert: insert the next character as it is
   redraw-current-line: redisplay the current line
   reverse-search-history: backward search in the history
   suspend: suspend ledit (send control-Z)
   transpose-chars: exchange the last two characters
   unix-line-discard: kill current line
   upcase-word: uppercase whole word
   yank: insert kill buffer
 

KNOWN BUGS

If ledit has been launched in a shell script, the suspend command kills it and its command... Use "exec ledit comm" instead of "ledit comm".
The suspend command stops ledit but not the called program. Do not do this if the called program is not waiting on standard input.
In some systems (e.g. alpha), pasting two many characters works bad and may block the terminal. Probably a kernel problem. No solution.

SEE ALSO

unicode_start(1), unicode_stop(1).

AUTHOR

Daniel de Rauglaudre, at INRIA, france.
daniel.de_rauglaudre@inria.fr