HOWTO: Mouse editing with readline in xterm

[Ilya Zakharevich]

Here is how to enable mouse-edition of the command line in recent xterm's:

a) After running ./configure, add -DOPT_READLINE to the Makefile.  [It
   is a bug in configure that one cannot do this easier ;-]

b) This enables the following new [undocumented :-(] control codes for
   DECSET etc:

#define SET_BUTTON1_MOVE_POINT      2001 /* click1 emit Esc seq to move point*/
#define SET_BUTTON2_MOVE_POINT      2002 /* press2 emit Esc seq to move point*/
#define SET_DBUTTON3_DELETE         2003 /* Double click-3 deletes */
#define SET_PASTE_IN_BRACKET        2004 /* Surround paste by escapes */
#define SET_PASTE_QUOTE             2005 /* Quote each char during paste */
#define SET_PASTE_LITERAL_NL        2006 /* Paste "\n" as C-j */

The reasonable sequence to enable this feature in ReadLine applications is:

  0) Decide which features are good for a given ReadLine library;

     E.g., for tcsh it is reasonable to use 2001;2002;2003.

     For bare GNU readline it is reasonable to use 2001;2002;2003;2005;2006.

     For applications which redefine many "usual keys" to do shortcuts
     (e.g., redefine "(" to insert a matched pair of parens) one could
     enable 2004, and bind F200 and F201 to switch off/on these
     bindings.  [2004 is an alternative to 2005.]

  1) Before showing the prompt, emit CSI ? Pm s to save the settings,
     then emit CSI ? Pm h to set new values.  After the command line
     editing is done, one should emit CSI ? Pm r to restore the old
     values.  Here Pm is the string discussed in (0), e.g.,
     "2001;2002;2003" (without quotes).

  2) If one has no such fine-grain control over the readline
     application, the poor man solution is to emit these sequences
     before and after running the application (instead of before and
     after editing a line).  However, in such cases xterm might
     emulate presses of Left and Right in "wrong moments".

Here is the example for tcsh:


            if ( $?SSH_CLIENT ) then
                set user_in_prompt = '%n@'
            else
                set user_in_prompt = ''
            endif
            setenv MOUSE_READLINE_ON 
'[?2001;2002;2003;2004;2005;2006s^[[?2001;2002;2003h'
            setenv MOUSE_READLINE_OFF '[?2001;2002;2003;2004;2005;2006r'
            set prompt = "%{^[]0;$user_in_prompt%m:    
%~/^G%}%U%m%u%B:%b%U%~%u%B%{$MOUSE_READLINE_ON%}->%b"
            alias post_cmd 'history -h 1 | perl -we '"'"'$_ = <STDIN>; chop; 
s/[;\x07\n][^\n]*/.../; s~^~\e]0;$ARGV[1]:$ARGV[0]/> ~; s/$/\x07/; 
s/\Q$ENV{HOME}/~/g; print $ENV{MOUSE_READLINE_OFF} if exists 
$ENV{MOUSE_READLINE_OFF}; print'"'"' $cwd $LOGNAME$__hostname'
            sched +0:00 alias postcmd post_cmd
            set __hostname=`hostname`

Enjoy,
Ilya