.\"	$OpenBSD: editline.7,v 1.2 2016/05/10 11:07:53 schwarze Exp $
.\"
.\" Copyright (c) 2016 Ingo Schwarze <schwarze@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: May 10 2016 $
.Dt EDITLINE 7
.Os
.Sh NAME
.Nm editline
.Nd line editing user interface
.Sh DESCRIPTION
When a program using the
.Xr editline 3
library prompts for an input string using the function
.Xr el_wgets 3 ,
it reads characters from the terminal.
Invalid input bytes that do not form characters are silently
discarded.
For each character read, one editor command is executed.
The mapping of input characters to editor commands depends on the
editing mode.
There are three editing modes:  vi insert mode, vi command mode,
and emacs mode.
The default is vi insert mode.
The program can switch the default to emacs mode by using the
.Xr el_set 3
or
.Xr el_parse 3
functions, and the user can switch to emacs mode either in the
.Xr editrc 5
configuration file or interactively with the
.Ic ed-command
editor command, in all three cases executing the
.Ic bind Fl e
builtin command.
.Pp
If trying to read from the terminal results in end of file or an
error, the library signals end of file to the program and does not
return a string.
.Ss Input character bindings
All default bindings described below can be overridden by individual
programs and can be changed with the
.Xr editrc 5
.Ic bind
builtin command.
.Pp
In the following tables,
.Sq Ctrl-
indicates a character with the bit 0x40 flipped, and
.Sq Meta-
indicates a character with the bit 0x80 set.
In vi insert mode and in emacs mode, all Meta-characters considered
printable by the current
.Xr locale 1
are bound to
.Ic ed-insert
instead of to the editor command listed below.
Consequently, in UTF-8 mode, most of the Meta-characters are not
directly accessible because their code points are occupied by
printable Unicode characters, and Meta-characters are usually input
using the
.Ic em-meta-next
editor command.
For example, to enter
.Sq Meta-B
in order to call the
.Ic ed-prev-word
editor command in emacs mode, call
.Ic em-meta-next
by pressing and releasing the escape key (or equivalently, Ctrl-[),
then press and release the
.Sq B
key.
If you have configured a Meta-key on your keyboard, for example
with
.Ql setxkbmap -option altwin:left_meta_win ,
the Ctrl-Meta-characters are directly accessible.
For example, to enter
.Sq Ctrl-Meta-H
in order to call the
.Ic ed-delete-prev-word
editor command in emacs mode, hold down the keys
.Sq Ctrl ,
.Sq Meta ,
and
.Sq H
at the same time.
Alternatively, press and release the escape key, then press and
release
.Sq Ctrl-H .
.Pp
In vi input mode, input characters are bound to the following editor
commands by default:
.Bl -column -offset indent "Ctrl-Z, TSTP" "ed-search-next-history"
.It Ctrl-D, EOF Ta Ic vi-list-or-eof
.It Ctrl-H, BS Ta Ic vi-delete-prev-char
.It Ctrl-J, LF Ta Ic ed-newline
.It Ctrl-M, CR Ta Ic ed-newline
.It Ctrl-Q Ta Ic ed-tty-start-output
.It Ctrl-S Ta Ic ed-tty-stop-output
.It Ctrl-U Ta Ic vi-kill-line-prev
.It Ctrl-V Ta Ic ed-quoted-insert
.It Ctrl-W Ta Ic ed-delete-prev-word
.It Ctrl-[, ESC Ta Ic vi-command-mode
.It Ctrl-\e, QUIT Ta Ic ed-tty-sigquit
.It Ctrl-?, DEL Ta Ic vi-delete-prev-char
.El
.Pp
All other input characters except the NUL character (Ctrl-@) are
bound to
.Ic ed-insert .
.Pp
In vi command mode, input characters are bound to the following
editor commands by default:
.Bl -column -offset indent "Ctrl-Z, TSTP" "ed-search-next-history"
.It Ctrl-A Ta Ic ed-move-to-beg
.It Ctrl-C, INT Ta Ic ed-tty-sigint
.It Ctrl-E Ta Ic ed-move-to-end
.It Ctrl-H, BS Ta Ic ed-delete-prev-char
.It Ctrl-J, LF Ta Ic ed-newline
.It Ctrl-K Ta Ic ed-kill-line
.It Ctrl-L, FF Ta Ic ed-clear-screen
.It Ctrl-M, CR Ta Ic ed-newline
.It Ctrl-N Ta Ic ed-next-history
.It Ctrl-O Ta Ic ed-tty-flush-output
.It Ctrl-P Ta Ic ed-prev-history
.It Ctrl-Q Ta Ic ed-tty-start-output
.It Ctrl-R Ta Ic ed-redisplay
.It Ctrl-S Ta Ic ed-tty-stop-output
.It Ctrl-U Ta Ic vi-kill-line-prev
.It Ctrl-W Ta Ic ed-delete-prev-word
.It Ctrl-[, ESC Ta Ic em-meta-next
.It Ctrl-\e, QUIT Ta Ic ed-tty-sigquit
.It Space Ta Ic ed-next-char
.It # Ta Ic vi-comment-out
.It $ Ta Ic ed-move-to-end
.It % Ta Ic vi-match
.It + Ta Ic ed-next-history
.It \&, Ta Ic vi-repeat-prev-char
.It - Ta Ic ed-prev-history
.It \&. Ta Ic vi-redo
.It / Ta Ic vi-search-prev
.It 0 Ta Ic vi-zero
.It 1 to 9 Ta Ic ed-argument-digit
.It \&: Ta Ic ed-command
.It \&; Ta Ic vi-repeat-next-char
.It \&? Ta Ic vi-search-next
.It @ Ta Ic vi-alias
.It A Ta Ic vi-add-at-eol
.It B Ta Ic vi-prev-big-word
.It C Ta Ic vi-change-to-eol
.It D Ta Ic ed-kill-line
.It E Ta Ic vi-end-big-word
.It F Ta Ic vi-prev-char
.It G Ta Ic vi-to-history-line
.It I Ta Ic vi-insert-at-bol
.It J Ta Ic ed-search-next-history
.It K Ta Ic ed-search-prev-history
.It N Ta Ic vi-repeat-search-prev
.It O Ta Ic ed-sequence-lead-in
.It P Ta Ic vi-paste-prev
.It R Ta Ic vi-replace-mode
.It S Ta Ic vi-substitute-line
.It T Ta Ic vi-to-prev-char
.It U Ta Ic vi-undo-line
.It W Ta Ic vi-next-big-word
.It X Ta Ic ed-delete-prev-char
.It Y Ta Ic vi-yank-end
.It \&[ Ta Ic ed-sequence-lead-in
.It ^ Ta Ic ed-move-to-beg
.It _ Ta Ic vi-history-word
.It a Ta Ic vi-add
.It b Ta Ic vi-prev-word
.It c Ta Ic vi-change-meta
.It d Ta Ic vi-delete-meta
.It e Ta Ic vi-end-word
.It f Ta Ic vi-next-char
.It h Ta Ic ed-prev-char
.It i Ta Ic vi-insert
.It j Ta Ic ed-next-history
.It k Ta Ic ed-prev-history
.It l Ta Ic ed-next-char
.It n Ta Ic vi-repeat-search-next
.It p Ta Ic vi-paste-next
.It r Ta Ic vi-replace-char
.It s Ta Ic vi-substitute-char
.It t Ta Ic vi-to-next-char
.It u Ta Ic vi-undo
.It v Ta Ic vi-histedit
.It w Ta Ic vi-next-word
.It x Ta Ic ed-delete-next-char
.It y Ta Ic vi-yank
.It \&| Ta Ic vi-to-column
.It ~ Ta Ic vi-change-case
.It Ctrl-?, DEL Ta Ic ed-delete-prev-char
.It Meta-O Ta Ic ed-sequence-lead-in
.It Meta-[ Ta Ic ed-sequence-lead-in
.El
.Pp
In emacs mode, input characters are bound to the following editor
commands by default:
.Bl -column -offset indent "Ctrl-Z, TSTP" "ed-search-next-history"
.It 0 to 9 Ta Ic ed-digit
.It Ctrl-@, NUL Ta Ic em-set-mark
.It Ctrl-A Ta Ic ed-move-to-beg
.It Ctrl-B Ta Ic ed-prev-char
.It Ctrl-C, INT Ta Ic ed-tty-sigint
.It Ctrl-D, EOF Ta Ic em-delete-or-list
.It Ctrl-E Ta Ic ed-move-to-end
.It Ctrl-F Ta Ic ed-next-char
.It Ctrl-H, BS Ta Ic em-delete-prev-char
.It Ctrl-J, LF Ta Ic ed-newline
.It Ctrl-K Ta Ic ed-kill-line
.It Ctrl-L, FF Ta Ic ed-clear-screen
.It Ctrl-M, CR Ta Ic ed-newline
.It Ctrl-N Ta Ic ed-next-history
.It Ctrl-O Ta Ic ed-tty-flush-output
.It Ctrl-P Ta Ic ed-prev-history
.It Ctrl-Q Ta Ic ed-tty-start-output
.It Ctrl-R Ta Ic ed-redisplay
.It Ctrl-S Ta Ic ed-tty-stop-output
.It Ctrl-T Ta Ic ed-transpose-chars
.It Ctrl-U Ta Ic ed-kill-line
.It Ctrl-V Ta Ic ed-quoted-insert
.It Ctrl-W Ta Ic em-kill-region
.It Ctrl-X Ta Ic ed-sequence-lead-in
.It Ctrl-Y Ta Ic em-yank
.It Ctrl-Z, TSTP Ta Ic ed-tty-sigtstp
.It Ctrl-[, ESC Ta Ic em-meta-next
.It Ctrl-\e, QUIT Ta Ic ed-tty-sigquit
.It Ctrl-] Ta Ic ed-tty-dsusp
.It Ctrl-?, DEL Ta Ic em-delete-prev-char
.It Ctrl-Meta-H Ta Ic ed-delete-prev-word
.It Ctrl-Meta-L Ta Ic ed-clear-screen
.It Ctrl-Meta-_ Ta Ic em-copy-prev-word
.It Meta-0 to 9 Ta Ic ed-argument-digit
.It Meta-B Ta Ic ed-prev-word
.It Meta-C Ta Ic em-capitol-case
.It Meta-D Ta Ic em-delete-next-word
.It Meta-F Ta Ic em-next-word
.It Meta-L Ta Ic em-lower-case
.It Meta-N Ta Ic ed-search-next-history
.It Meta-O Ta Ic ed-sequence-lead-in
.It Meta-P Ta Ic ed-search-prev-history
.It Meta-U Ta Ic em-upper-case
.It Meta-W Ta Ic em-copy-region
.It Meta-X Ta Ic ed-command
.It Meta-[ Ta Ic ed-sequence-lead-in
.It Meta-b Ta Ic ed-prev-word
.It Meta-c Ta Ic em-capitol-case
.It Meta-d Ta Ic em-delete-next-word
.It Meta-f Ta Ic em-next-word
.It Meta-l Ta Ic em-lower-case
.It Meta-n Ta Ic ed-search-next-history
.It Meta-p Ta Ic ed-search-prev-history
.It Meta-u Ta Ic em-upper-case
.It Meta-w Ta Ic em-copy-region
.It Meta-x Ta Ic ed-command
.It Ctrl-Meta-? Ta Ic ed-delete-prev-word
.El
.Pp
The remaining
.Xr ascii 7
characters in the range 0x20 to 0x7e are bound to
.Ic ed-insert .
.Pp
If standard output is not connected to a terminal device
or
.Xr el_set 3
was used to set
.Dv EL_EDITMODE
to 0, all input character bindings are disabled and all characters
typed are appended to the edit buffer.
In that case, the edit buffer is returned to the program after a
newline or carriage return character is typed, or after the first
character typed if
.Xr el_set 3
was used to set
.Dv EL_UNBUFFERED
to non-zero.
.Ss Editor commands
Most editor commands accept an optional argument.
The argument is entered by prefixing the editor command with one
or more of the editor commands
.Ic ed-argument-digit ,
.Ic ed-digit ,
.Ic em-universal-argument ,
or
.Ic vi-zero .
When an argument is not provided, it defaults to 1.
For most editor commands, the effect of an argument is to repeatedly
execute the command that number of times.
.Pp
When talking about a character string from a left character to a
right character, the left character is included in the string, while
the right character is not included.
.Pp
If an editor command causes an error, the input character is discarded,
no action occurs, and the terminal bell is rung.
In case of a non-fatal error, the terminal bell is also rung,
but the editor command takes effect anyway.
.Pp
In the following list, the default key bindings are listed after
each editor command.
.Bl -tag -width 4n
.It Ic ed-argument-digit Pq vi command: 1 to 9; emacs: Meta-0 to Meta-9
If in argument input mode, append the input digit to the argument
being read.
Otherwise, switch to argument input mode and use the input digit
as the most significant digit of the argument.
It is an error if the input character is not a digit or if the
existing argument is already greater than a million.
.It Ic ed-clear-screen Pq vi command: Ctrl-L; emacs: Ctrl-L, Ctrl-Meta-L
Clear the screen and display the edit buffer at the top.
Ignore any argument.
.It Ic ed-command Pq vi command: So \&: Sc ; emacs: Meta-X, Meta-x
Read a line from the terminal bypassing the normal line editing
functionality and execute that line as an
.Xr editrc 5
builtin command.
If in vi command mode, also switch back to vi insert mode.
Ignore any argument.
.It Ic ed-delete-next-char Pq vi command: x
Delete the character at the cursor position.
With an argument, delete that number of characters.
In emacs mode, it is an error if the cursor is at the end of the
edit buffer.
In vi mode, the last character in the edit buffer is deleted in
that case, and it is an error if the buffer is empty.
.It Ic ed-delete-prev-char Pq vi command: X, Ctrl-H, BS, Ctrl-?, DEL
Delete the character to the left of the cursor position.
With an argument, delete that number of characters.
It is an error if the cursor is at the beginning of the edit buffer.
.It Ic ed-delete-prev-word Pq vi: Ctrl-W; emacs: Ctrl-Meta-H, Ctrl-Meta-?
Move to the left to the closest beginning of a word, delete the
string from that position to the cursor, and save it to the cut
buffer.
With an argument, delete that number of words.
It is an error if the cursor is at the beginning of the edit buffer.
.It Ic ed-digit Pq emacs: 0 to 9
If in argument input mode, append the input digit to the argument
being read.
Otherwise, call
.Ic ed-insert .
It is an error if the input character is not a digit or if the
existing argument is already greater than a million.
.It Ic ed-end-of-file Pq not bound by default
Discard the edit buffer and indicate end of file to the program.
Ignore any argument.
.It Ic ed-ignore Pq various
Discard the input character and do nothing.
.It Ic ed-insert Pq vi input: almost all; emacs: printable characters
In insert mode, insert the input character left of the cursor
position.
In replace mode, overwrite the character at the cursor and move the
cursor to the right by one character position.
Accept an argument to do this repeatedly.
It is an error if the input character is the NUL character (Ctrl-@).
Failure to enlarge the edit buffer also results in an error.
.It Ic ed-kill-line Pq vi command: D, Ctrl-K; emacs: Ctrl-K, Ctrl-U
Delete the string from the cursor position to the end of the line
and save it to the cut buffer.
Ignore any argument.
.It Ic ed-move-to-beg Pq vi command: ^, Ctrl-A; emacs: Ctrl-A
In vi mode, move the cursor to the first non-space character in the
edit buffer.
In emacs mode, move the cursor to the beginning of the edit buffer.
Ignore any argument.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
.It Ic ed-move-to-end Pq vi command: $, Ctrl-E; emacs: Ctrl-E
Move the cursor to the end of the edit buffer.
Ignore any argument.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
.It Ic ed-newline Pq all modes: Ctrl-J, LF, Ctrl-M, CR
Append a newline character to the edit buffer and return the edit
buffer to the program.
Ignore any argument.
.It Ic ed-next-char Pq vi command: Space, l; emacs: Ctrl-F
Move the cursor one character position to the right.
With an argument, move by that number of characters.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if the cursor is already at the end of the edit
buffer.
.It Ic ed-next-history Pq vi command: j, +, Ctrl-N; emacs: Ctrl-N
Replace the edit buffer with the next history line.
That line is older than the current line.
With an argument, go forward by that number of history lines.
It is a non-fatal error to advance by more lines than are available.
.It Ic ed-next-line Pq not bound by default
Move the cursor down one line.
With an argument, move down by that number of lines.
It is an error if the edit buffer does not contain enough newline
characters to the right of the cursor position.
.It Ic ed-prev-char Pq vi command: h; emacs: Ctrl-B
Move the cursor one character position to the left.
With an argument, move by that number of characters.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if the cursor is already at the beginning of the
edit buffer.
.It Ic ed-prev-history Pq vi command: k, -, Ctrl-P; emacs: Ctrl-P
Replace the edit buffer with the previous history line.
That line is newer than the current line.
With an argument, go back by that number of lines.
It is a non-fatal error to back up by more lines than are available.
.It Ic ed-prev-line Pq not bound by default
Move the cursor up one line.
With an argument, move up by that number of lines.
It is an error if the edit buffer does not contain enough newline
characters to the left of the cursor position.
.It Ic ed-prev-word Pq emacs: Meta-B, Meta-b
Move the cursor to the left to the closest beginning of a word.
With an argument, repeat that number of times.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if the cursor is already at the beginning of the
edit buffer.
.It Ic ed-quoted-insert Pq vi insert, emacs: Ctrl-V
Read one character from the terminal bypassing the normal line
editing functionality and call
.Ic ed-insert
on it.
If trying to read the character returns end of file or an error,
call
.Ic ed-end-of-file
instead.
.It Ic ed-redisplay Pq vi command, emacs: Ctrl-R
Redisplay everything.
Ignore any argument.
.It Ic ed-search-next-history Pq vi command: J; emacs: Meta-N, Meta-n
Replace the edit buffer with the next matching history entry.
.It Ic ed-search-prev-history Pq vi command: K; emacs: Meta-P, Meta-p
Replace the edit buffer with the previous matching history entry.
.It Ic ed-sequence-lead-in Pq vi cmd: O, \&[; emacs: Ctrl-X;\
 both: Meta-O, Meta-[
Call a macro.
See the section about
.Sx Macros
below for details.
.It Ic ed-start-over Pq not bound by default
Discard the contents of the edit buffer and start from scratch.
Ignore any argument.
.It Ic ed-transpose-chars Pq emacs: Ctrl-T
Exchange the character at the cursor position with the one to the
left of it and move the cursor to the character to the right of the
two exchanged characters.
Ignore any argument.
It is an error if the cursor is at the beginning of the edit buffer
or if the edit buffer contains less than two characters.
.It Ic ed-unassigned Pq all characters not listed
This editor command always results in an error.
.It Ic em-capitol-case Pq emacs: Meta-C, Meta-c
Capitalize the string from the cursor to the end of the current
word.
That is, if it contains at least one alphabetic character, convert
the first alphabetic character to upper case, and convert all
characters to the right of it to lower case.
In any case, move the cursor to the next character after the end
of the current word.
.It Ic em-copy-prev-word Pq emacs: Ctrl-Meta-_
Copy the string from the beginning of the current word to the cursor
and insert it to the left of the cursor.
Move the cursor to the character after the inserted string.
It is an error if the cursor is at the beginning of the edit buffer.
.It Ic em-copy-region Pq emacs: Meta-W, Meta-w
Copy the string from the cursor to the mark to the cut buffer.
It is an error if the mark is not set.
.It Ic em-delete-next-word Pq emacs: Meta-D, Meta-d
Delete the string from the cursor to the end of the current word
and save it to the cut buffer.
It is an error if the cursor is at the end of the edit buffer.
.It Ic em-delete-or-list Pq emacs: Ctrl-D, EOF
If the cursor is not at the end of the line, delete the character
at the cursor.
If the edit buffer is empty, indicate end of file to the program.
It is an error if the cursor is at the end of the edit buffer and
the edit buffer is not empty.
.It Ic em-delete-prev-char Pq emacs: Ctrl-H, BS, Ctrl-?, DEL
Delete the character to the left of the cursor.
It is an error if the cursor is at the beginning of the edit buffer.
.It Ic em-exchange-mark Pq not bound by default
Exchange the cursor and the mark.
.It Ic em-gosmacs-transpose Pq not bound by default
Exchange the two characters to the left of the cursor.
It is an error if the cursor is on the first or second character
of the edit buffer.
.It Ic em-inc-search-next Pq not bound by default
Emacs incremental next search.
.It Ic em-inc-search-prev Pq not bound by default
Emacs incremental reverse search.
.It Ic em-kill-line Pq not bound by default
Delete the entire contents of the edit buffer and save it to the
cut buffer.
.It Ic em-kill-region Pq emacs: Ctrl-W
Delete the string from the cursor to the mark and save it to the
cut buffer.
It is an error if the mark is not set.
.It Ic em-lower-case Pq emacs: Meta-L, Meta-l
Convert the characters from the cursor to the end of the current
word to lower case.
.It Ic em-meta-next Pq vi command, emacs: Ctrl-[, ESC
Set the bit 0x80 on the next character typed.
Unless the resulting code point is printable, holding down the
.Sq Meta-
key while typing that character is a simpler way to achieve the
same effect.
.It Ic em-next-word Pq Meta-F, Meta-f
Move the cursor to the end of the current word.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if the cursor is already at the end of the edit
buffer.
.It Ic em-set-mark Pq emacs: Ctrl-Q, NUL
Set the mark at the current cursor position.
.It Ic em-toggle-overwrite Pq not bound by default
Switch from insert to overwrite mode or vice versa.
.It Ic em-universal-argument Pq not bound by default
If in argument input mode, multiply the argument by 4.
Otherwise, switch to argument input mode and set the argument to 4.
It is an error if the existing argument is already greater than a
million.
.It Ic em-upper-case Pq emacs: Meta-U, Meta-u
Convert the characters from the cursor to the end of the current
word to upper case.
.It Ic em-yank Pq emacs: Ctrl-Y
Paste the cut buffer to the left of the cursor.
.It Ic vi-add Pq vi command: a
Switch to vi insert mode.
Unless the cursor is already at the end of the edit buffer, move
it one character position to the right.
.It Ic vi-add-at-eol Pq vi command: A
Switch to vi insert mode and move the cursor to the end of the edit
buffer.
.It Ic vi-alias Pq vi command: @
If an alias function was defined by calling the
.Xr el_set 3
or
.Xr el_wset 3
function with the argument
.Dv EL_ALIAS_TEXT ,
read one character from the terminal bypassing the normal line
editing functionality, call the alias function passing the argument that was specified with
.Dv EL_ALIAS_TEXT
as the first argument and the character read, with an underscore
prepended, as the second argument, and pass the string returned
from the alias function to
.Xr el_wpush 3 .
It is an error if no alias function is defined or if trying to read
the character results in end of file or an error.
.It Ic vi-change-case Pq vi command: ~
Change the case of the character at the cursor and move the cursor
one character position to the right.
It is an error if the cursor is already at the end of the edit
buffer.
.It Ic vi-change-meta Pq vi command: c
Delete the string from the cursor to the position specified by the
following movement command and save a copy of it to the cut buffer.
When given twice in a row, instead delete the whole contents of the
edit buffer and save a copy of it to the cut buffer.
In either case, switch to vi insert mode after that.
.It Ic vi-change-to-eol Pq vi command: C
Delete the string from the cursor position to the end of the line
and save it to the cut buffer, then switch to vi insert mode.
.It Ic vi-command-mode Pq vi insert: Ctrl-[, ESC
Discard pending actions and arguments and switch to vi command mode.
Unless the cursor is already at the beginning of the edit buffer,
move it to the left by one character position.
.It Ic vi-comment-out Pq vi command: #
Insert a
.Sq #
character at the beginning of the edit buffer and return the edit
buffer to the program.
.It Ic vi-delete-meta Pq vi command: d
Delete the string from the cursor to the position specified by the
following movement command and save a copy of it to the cut buffer.
When given twice in a row, instead delete the whole contents of the
edit buffer and save a copy of it to the cut buffer.
.It Ic vi-delete-prev-char Pq vi insert: Ctrl-H, BS, Ctrl-?, DEL
Delete the character to the left of the cursor.
It is an error if the cursor is already at the beginning of the
edit buffer.
.It Ic vi-end-big-word Pq vi command: E
Move the cursor to the end of the current space delimited word.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if the cursor is already at the end of the edit
buffer.
.It Ic vi-end-word Pq vi command: e
Move the cursor to the end of the current word.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if the cursor is already at the end of the edit
buffer.
.It Ic vi-history-word Pq vi command: _
Insert the first word from the most recent history entry after the
cursor, move the cursor after to the character after the inserted
word, and switch to vi insert mode.
It is an error if there is no history entry or the most recent
history entry is empty.
.It Ic vi-insert Pq vi command: i
Enter insert mode.
.It Ic vi-insert-at-bol Pq vi command: I
Move the cursor to the beginning of the edit buffer and switch to
vi insert mode.
.It Ic vi-kill-line-prev Pq vi: Ctrl-U
Delete the string from the beginning of the edit buffer to the
cursor and save it to the cut buffer.
.It Ic vi-list-or-eof Pq vi insert: Ctrl-D, EOF
If the edit buffer is empty, indicate end of file to the program.
It is an error if the edit buffer is not empty.
.It Ic vi-match Pq vi command: %
Consider opening and closing parentheses, braces, and brackets as
delimiters.
If the cursor is not at a delimiter, move it to the right until it
gets to one, then move it to the matching delimiter.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if there is no delimiter at the cursor or in the
string to the right of the cursor, or if the first such delimiter
has no matching delimiter.
.It Ic vi-next-big-word Pq vi command: W
Move the cursor to the right to the beginning of the next space
delimited word.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if the cursor is already at the end of the edit
buffer or on its last character.
.It Ic vi-next-char Pq vi command: f
Read one character from the terminal bypassing the normal line
editing functionality and move the cursor to the right to the next
instance of that character in the edit buffer.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
If trying to read the character results in end of file or an error,
call
.Ic ed-end-of-file
instead.
It is an error if the character is not found searching to the right
in the edit buffer.
.It Ic vi-next-word Pq vi command: w
Move the cursor to the right to the beginning of the next word.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if the cursor is already at the end of the edit
buffer or on its last character.
.It Ic vi-paste-next Pq vi command: p
Insert a copy of the cut buffer to the right of the cursor.
It is an error if the cut buffer is empty.
.It Ic vi-paste-prev Pq vi command: P
Insert a copy of the cut buffer to the left of the cursor.
It is an error if the cut buffer is empty.
.It Ic vi-prev-big-word Pq vi command: B
Move the cursor to the left to the next beginning of a space delimited
word.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if the cursor is already at the beginning of the
edit buffer.
.It Ic vi-prev-char Pq vi command: F
Read one character from the terminal bypassing the normal line
editing functionality and move the cursor to the left to the next
instance of that character in the edit buffer.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
If trying to read the character results in end of file or an error,
call
.Ic ed-end-of-file
instead.
It is an error if the character is not found searching to the left
in the edit buffer.
.It Ic vi-prev-word Pq vi command: b
Move the cursor to the left to the next beginning of a word.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
It is an error if the cursor is already at the beginning of the
edit buffer.
.It Ic vi-redo Pq vi command: Sq \&.
Redo the last non-motion command.
.It Ic vi-repeat-next-char Pq vi command: Sq \&;
Repeat the most recent character search in the same search direction.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
.It Ic vi-repeat-prev-char Pq vi command: Sq \&,
Repeat the most recent character search in the opposite search
direction.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
.It Ic vi-repeat-search-next Pq vi command: n
Repeat the most recent history search in the same search direction.
.It Ic vi-repeat-search-prev Pq vi command: N
Repeat the most recent history search in the opposite search
direction.
.It Ic vi-replace-char Pq vi command: r
Switch to vi replace mode, and automatically switch back to vi
command mode after the next character typed.
See
.Ic ed-insert
for a description of replace mode.
It is an error if the cursor is at the end of the edit buffer.
.It Ic vi-replace-mode Pq vi command: R
Switch to vi replace mode.
This is a variant of vi insert mode; see
.Ic ed-insert
for the difference.
.It Ic vi-search-next Pq vi command: \&?
Replace the edit buffer with the next matching history entry.
.It Ic vi-search-prev Pq vi command: /
Replace the edit buffer with the previous matching history entry.
.It Ic vi-substitute-char Pq vi command: s
Delete the character at the cursor and switch to vi insert mode.
.It Ic vi-substitute-line Pq vi command: S
Delete the entire contents of the edit buffer, save a copy of it
in the cut buffer, and enter vi insert mode.
.It Ic vi-to-column Pq vi command: \&|
Move the cursor to the column specified as the argument.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
.It Ic vi-to-history-line Pq vi command: G
Replace the edit buffer with the specified history entry.
.It Ic vi-to-next-char Pq vi command: t
Read one character from the terminal bypassing the normal line
editing functionality and move the cursor to the right to the
character before the next instance of that character in the edit
buffer.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
If trying to read the character results in end of file or an error,
call
.Ic ed-end-of-file
instead.
It is an error if the character is not found searching to the right
in the edit buffer.
.It Ic vi-to-prev-char Pq vi command: T
Read one character from the terminal bypassing the normal line
editing functionality and move the cursor to the left to the character
after the next instance of that character in the edit buffer.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
If trying to read the character results in end of file or an error,
call
.Ic ed-end-of-file
instead.
It is an error if the character is not found searching to the left
in the edit buffer.
.It Ic vi-undo Pq vi command: u
Undo the last change.
.It Ic vi-undo-line Pq vi command: U
Undo all changes to the edit buffer.
.It Ic vi-yank Pq vi command: y
Copy the string from the cursor to the position specified by the
following movement command to the cut buffer.
When given twice in a row, instead copy the whole contents of the
edit buffer to the cut buffer.
.It Ic vi-yank-end Pq vi command: Y
Copy the string from the cursor to the end of the edit buffer to
the cut buffer.
.It Ic vi-zero Pq vi command: 0
If in argument input mode, multiply the argument by ten.
Otherwise, move the cursor to the beginning of the edit buffer.
Can be used as a movement command after
.Ic vi_change_meta ,
.Ic vi_delete_meta ,
or
.Ic vi_yank .
.El
.Ss Macros
If an input character is bound to the editor command
.Ic ed-sequence-lead-in ,
.Nm
attempts to call a macro.
If the input character by itself forms the name of a macro, that
macro is executed.
Otherwise, additional input characters are read until the string
read forms the name of a macro, in which case that macro is executed,
or until the string read matches the beginning of none of the existing
macro names, in which case the string including the final, mismatching
character is discarded and the terminal bell is rung.
.Pp
There are two kinds of macros.
Command macros execute a single editor command.
Keyboard macros return a string of characters that is appended
as a new line to the
.Sx Input Queue .
.Pp
The following command macros are defined by default in vi command
mode and in emacs mode:
.Bl -column -offset indent "Esc O A, Esc O A" "em-exchange-mark"
.It Esc \&[ A, Esc O A Ta Ic ed-prev-history
.It Esc \&[ B, Esc O B Ta Ic ed-next-history
.It Esc \&[ C, Esc O C Ta Ic ed-next-char
.It Esc \&[ D, Esc O D Ta Ic ed-prev-char
.It Esc \&[ F, Esc O F Ta Ic ed-move-to-end
.It Esc \&[ H, Esc O H Ta Ic ed-move-to-beg
.El
.Pp
In vi command mode, they are also defined by default without the
initial escape character.
.Pp
In addition, the
.Nm
library tries to bind the strings generated by the arrow keys
as reported by the
.Xr terminfo 5
database to these editor commands, unless that would clobber
user settings.
.Pp
In emacs mode, the two-character string
.Dq Ctrl-X Ctrl-X
is bound to the
.Ic em-exchange-mark
editor command.
.Ss Input Queue
The
.Nm
library maintains an input queue operated in FIFO mode.
Whenever it needs an input character, it takes the first character
from the first line of the input queue.
When the queue is empty, it reads from the terminal.
.Pp
A line can be appended to the end of the input queue in several ways:
.Bl -dash -offset indent
.It
By calling one of the keyboard
.Sx Macros .
.It
By calling the editor command
.Ic vi-redo .
.It
By calling the editor command
.Ic vi-alias .
.It
By pressing a key in emacs incremental search mode that doesn't
have a special meaning in that mode but returns to normal emacs
mode.
.It
If an application program directly calls the functions
.Xr el_push 3
or
.Xr el_wpush 3 ,
it can provide additional, program-specific ways
of appending to the input queue.
.El
.Sh SEE ALSO
.Xr mg 1 ,
.Xr vi 1 ,
.Xr editline 3 ,
.Xr editrc 5
.Sh HISTORY
This manual page first appeared in
.Ox 6.0 .
.Sh AUTHORS
.An -nosplit
This manual page was written by
.An Ingo Schwarze Aq Mt schwarze@openbsd.org .