Customizing the Keyboard
The command line editing and history is provided by the libtecla library. This library is configurable.
Editing mode can be changed: (emacs or vi) [default: emacs]
Keyboard character sequence to command bindings
The libtecla configuration file for yangcli-pro and yp-shell
is called $HOME/.teclarc. If this file is found then the
settings will be applied when the program starts.
Any number of key binding lines can be present
in this file.
Changing the Editing Mode
Key bindings for the "emacs" or "vi" editor can be selected. The default mode is "emacs". To change the mode to "vi", use the following line in the .teclarc file:
edit-mode vi
Changing Key Bindings
The key bindings within an edit mode (emacs or vi) can be changed with the 'bind' command.
Example .teclarc:
bind C-w backward-delete-word
This command would change the function bound to the Control-w key sequence. The default mapping is 'kill-region' and this 'bind' command will change the binding for Control-w to 'backward-delete-word'.
Refer to the tecla documentation for details on all the key bindings available and default key bindings.
The following sections are from the libtecla documentation, and describe the key bindings available, and the default key bindings used in yangcli-pro.
Available Key Bindings
user-interrupt - Send a SIGINT signal to the
parent process.
abort - Send a SIGABRT signal to the
parent process.
suspend - Suspend the parent process.
stop-output - Pause terminal output.
start-output - Resume paused terminal output.
literal-next - Arrange for the next character
to be treated as a normal
character. This allows control
characters to be entered.
cursor-right - Move the cursor one character
right.
cursor-left - Move the cursor one character
left.
insert-mode - Toggle between insert mode and
overwrite mode.
beginning-of-line - Move the cursor to the
beginning of the line.
end-of-line - Move the cursor to the end of
the line.
delete-line - Delete the contents of the
current line.
kill-line - Delete everything that follows
the cursor.
backward-kill-line - Delete all characters between
the cursor and the start of the
line.
forward-word - Move to the end of the word
which follows the cursor.
forward-to-word - Move the cursor to the start of
the word that follows the
cursor.
backward-word - Move to the start of the word
which precedes the cursor.
goto-column - Move the cursor to the
1-relative column in the line
specified by any preceding
digit-argument sequences (see
ENTERING REPEAT COUNTS below).
find-parenthesis - If the cursor is currently
over a parenthesis character,
move it to the matching
parenthesis character. If not
over a parenthesis character
move right to the next close
parenthesis.
forward-delete-char - Delete the character under the
cursor.
backward-delete-char - Delete the character which
precedes the cursor.
list-or-eof - This is intended for binding
to ^D. When invoked when the
cursor is within the line it
displays all possible
completions then redisplays
the line unchanged. When
invoked on an empty line, it
signals end-of-input (EOF) to
the caller of gl_get_line().
del-char-or-list-or-eof - This is intended for binding
to ^D. When invoked when the
cursor is within the line it
invokes forward-delete-char.
When invoked at the end of the
line it displays all possible
completions then redisplays
the line unchanged. When
invoked on an empty line, it
signals end-of-input (EOF) to
the caller of gl_get_line().
forward-delete-word - Delete the word which follows
the cursor.
backward-delete-word - Delete the word which precedes
the cursor.
upcase-word - Convert all of the characters
of the word which follows the
cursor, to upper case.
downcase-word - Convert all of the characters
of the word which follows the
cursor, to lower case.
capitalize-word - Capitalize the word which
follows the cursor.
change-case - If the next character is upper
case, toggle it to lower case
and vice versa.
redisplay - Redisplay the line.
clear-screen - Clear the terminal, then
redisplay the current line.
transpose-chars - Swap the character under the
cursor with the character just
before the cursor.
set-mark - Set a mark at the position of
the cursor.
exchange-point-and-mark - Move the cursor to the last
mark that was set, and move
the mark to where the cursor
used to be.
kill-region - Delete the characters that lie
between the last mark that was
set, and the cursor.
copy-region-as-kill - Copy the text between the mark
and the cursor to the cut
buffer, without deleting the
original text.
yank - Insert the text that was last
deleted, just before the
current position of the cursor.
append-yank - Paste the current contents of
the cut buffer, after the
cursor.
up-history - Recall the next oldest line
that was entered. Note that
in vi mode you are left in
command mode.
down-history - Recall the next most recent
line that was entered. If no
history recall session is
currently active, the next
line from a previous recall
session is recalled. Note that
in vi mode you are left in
command mode.
history-search-backward - Recall the next oldest line
who's prefix matches the string
which currently precedes the
cursor (in vi command-mode the
character under the cursor is
also included in the search
string). Note that in vi mode
you are left in command mode.
history-search-forward - Recall the next newest line
who's prefix matches the string
which currently precedes the
cursor (in vi command-mode the
character under the cursor is
also included in the search
string). Note that in vi mode
you are left in command mode.
history-re-search-backward -Recall the next oldest line
who's prefix matches that
established by the last
invocation of either
history-search-forward or
history-search-backward.
history-re-search-forward - Recall the next newest line
who's prefix matches that
established by the last
invocation of either
history-search-forward or
history-search-backward.
complete-word - Attempt to complete the
incomplete word which
precedes the cursor. Unless
the host program has customized
word completion, filename
completion is attempted. In vi
commmand mode the character
under the cursor is also
included in the word being
completed, and you are left in
vi insert mode.
expand-filename - Within the command line, expand
wild cards, tilde expressions
and dollar expressions in the
filename which immediately
precedes the cursor. In vi
commmand mode the character
under the cursor is also
included in the filename being
expanded, and you are left in
vi insert mode.
list-glob - List any filenames which match
the wild-card, tilde and dollar
expressions in the filename
which immediately precedes the
cursor, then redraw the input
line unchanged.
list-history - Display the contents of the
history list for the current
history group. If a repeat
count of > 1 is specified,
only that many of the most
recent lines are displayed.
See the "ENTERING REPEAT
COUNTS" section.
read-from-file - Temporarily switch to reading
input from the file who's
name precedes the cursor.
read-init-files - Re-read teclarc configuration
files.
beginning-of-history - Move to the oldest line in the
history list. Note that in vi
mode you are left in command
mode.
end-of-history - Move to the newest line in the
history list (ie. the current
line). Note that in vi mode
this leaves you in command
mode.
digit-argument - Enter a repeat count for the
next key-binding function.
For details, see the ENTERING
REPEAT COUNTS section.
newline - Terminate and return the
current contents of the
line, after appending a
newline character. The newline
character is normally '\n',
but will be the first
character of the key-sequence
that invoked the newline
action, if this happens to be
a printable character. If the
action was invoked by the
'\n' newline character or the
'\r' carriage return
character, the line is
appended to the history
buffer.
repeat-history - Return the line that is being
edited, then arrange for the
next most recent entry in the
history buffer to be recalled
when Tecla is next called.
Repeatedly invoking this
action causes successive
historical input lines to be
re-executed. Note that this
action is equivalent to the
'Operate' action in ksh.
ring-bell - Ring the terminal bell, unless
the bell has been silenced via
the nobeep configuration
option (see THE TECLA
CONFIGURATION FILE section).
forward-copy-char - Copy the next character into
the cut buffer (NB. use repeat
counts to copy more than one).
backward-copy-char - Copy the previous character
into the cut buffer.
forward-copy-word - Copy the next word into the cut
buffer.
backward-copy-word - Copy the previous word into the
cut buffer.
forward-find-char - Move the cursor to the next
occurrence of the next
character that you type.
backward-find-char - Move the cursor to the last
occurrence of the next
character that you type.
forward-to-char - Move the cursor to the
character just before the next
occurrence of the next
character that the user types.
backward-to-char - Move the cursor to the
character just after the last
occurrence before the cursor
of the next character that the
user types.
repeat-find-char - Repeat the last
backward-find-char,
forward-find-char,
backward-to-char or
forward-to-char.
invert-refind-char - Repeat the last
backward-find-char,
forward-find-char,
backward-to-char, or
forward-to-char in the
opposite direction.
delete-to-column - Delete the characters from the
cursor up to the column that
is specified by the repeat
count.
delete-to-parenthesis - Delete the characters from the
cursor up to and including
the matching parenthesis, or
next close parenthesis.
forward-delete-find - Delete the characters from the
cursor up to and including the
following occurence of the
next character typed.
backward-delete-find - Delete the characters from the
cursor up to and including the
preceding occurence of the
next character typed.
forward-delete-to - Delete the characters from the
cursor up to, but not
including, the following
occurence of the next
character typed.
backward-delete-to - Delete the characters from the
cursor up to, but not
including, the preceding
occurence of the next
character typed.
delete-refind - Repeat the last *-delete-find
or *-delete-to action.
delete-invert-refind - Repeat the last *-delete-find
or *-delete-to action, in the
opposite direction.
copy-to-column - Copy the characters from the
cursor up to the column that
is specified by the repeat
count, into the cut buffer.
copy-to-parenthesis - Copy the characters from the
cursor up to and including
the matching parenthesis, or
next close parenthesis, into
the cut buffer.
forward-copy-find - Copy the characters from the
cursor up to and including the
following occurence of the
next character typed, into the
cut buffer.
backward-copy-find - Copy the characters from the
cursor up to and including the
preceding occurence of the
next character typed, into the
cut buffer.
forward-copy-to - Copy the characters from the
cursor up to, but not
including, the following
occurence of the next
character typed, into the cut
buffer.
backward-copy-to - Copy the characters from the
cursor up to, but not
including, the preceding
occurence of the next
character typed, into the cut
buffer.
copy-refind - Repeat the last *-copy-find
or *-copy-to action.
copy-invert-refind - Repeat the last *-copy-find
or *-copy-to action, in the
opposite direction.
vi-mode - Switch to vi mode from emacs
mode.
emacs-mode - Switch to emacs mode from vi
mode.
vi-insert - From vi command mode, switch to
insert mode.
vi-overwrite - From vi command mode, switch to
overwrite mode.
vi-insert-at-bol - From vi command mode, move the
cursor to the start of the line
and switch to insert mode.
vi-append-at-eol - From vi command mode, move the
cursor to the end of the line
and switch to append mode.
vi-append - From vi command mode, move the
cursor one position right, and
switch to insert mode.
vi-replace-char - From vi command mode, replace
the character under the cursor
with the next character
entered.
vi-forward-change-char - From vi command mode, delete
the next character then enter
insert mode.
vi-backward-change-char - From vi command mode, delete
the preceding character then
enter insert mode.
vi-forward-change-word - From vi command mode, delete
the next word then enter
insert mode.
vi-backward-change-word - From vi command mode, delete
the preceding word then
enter insert mode.
vi-change-rest-of-line - From vi command mode, delete
from the cursor to the end of
the line, then enter insert
mode.
vi-change-line - From vi command mode, delete
the current line, then enter
insert mode.
vi-change-to-bol - From vi command mode, delete
all characters between the
cursor and the beginning of
the line, then enter insert
mode.
vi-change-to-column - From vi command mode, delete
the characters from the cursor
up to the column that is
specified by the repeat count,
then enter insert mode.
vi-change-to-parenthesis - Delete the characters from the
cursor up to and including
the matching parenthesis, or
next close parenthesis, then
enter vi insert mode.
vi-forward-change-find - From vi command mode, delete
the characters from the
cursor up to and including the
following occurence of the
next character typed, then
enter insert mode.
vi-backward-change-find - From vi command mode, delete
the characters from the
cursor up to and including the
preceding occurence of the
next character typed, then
enter insert mode.
vi-forward-change-to - From vi command mode, delete
the characters from the
cursor up to, but not
including, the following
occurence of the next
character typed, then enter
insert mode.
vi-backward-change-to - From vi command mode, delete
the characters from the
cursor up to, but not
including, the preceding
occurence of the next
character typed, then enter
insert mode.
vi-change-refind - Repeat the last
vi-*-change-find or
vi-*-change-to action.
vi-change-invert-refind - Repeat the last
vi-*-change-find or
vi-*-change-to action, in the
opposite direction.
vi-undo - In vi mode, undo the last
editing operation.
vi-repeat-change - In vi command mode, repeat the
last command that modified the
line.
Default Key Bindings for Emacs
The cursor keys are refered to by name, as follows. This is necessary because different types of terminals generate different key sequences when their cursor keys are pressed.
right -> cursor-right
left -> cursor-left
up -> up-history
down -> down-history
The remaining bindings don't depend on the terminal setttings.
^F -> cursor-right
^B -> cursor-left
M-i -> insert-mode
^A -> beginning-of-line
^E -> end-of-line
^U -> delete-line
^K -> kill-line
M-f -> forward-word
M-b -> backward-word
^D -> del-char-or-list-or-eof
^H -> backward-delete-char
^? -> backward-delete-char
M-d -> forward-delete-word
M-^H -> backward-delete-word
M-^? -> backward-delete-word
M-u -> upcase-word
M-l -> downcase-word
M-c -> capitalize-word
^R -> redisplay
^L -> clear-screen
^T -> transpose-chars
^@ -> set-mark
^X^X -> exchange-point-and-mark
^W -> kill-region
M-w -> copy-region-as-kill
^Y -> yank
^P -> up-history
^N -> down-history
M-p -> history-search-backward
M-n -> history-search-forward
^I -> complete-word
^X* -> expand-filename
^X^F -> read-from-file
^X^R -> read-init-files
^Xg -> list-glob
^Xh -> list-history
M-< -> beginning-of-history
M-> -> end-of-history
\n -> newline
\r -> newline
M-o -> repeat-history
M-^V -> vi-mode
M-0, M-1, ... M-9 -> digit-argument