[ksh93-integration-discuss] TAB-TAB completion patch #003 (which makes "gmacs" the default editor mode) / was: Re: [ast-users] RFE: Make TAB completion in ksh93 work like ESC-'='...

[Roland Mainz]

Roland Mainz wrote:
> Roland Mainz wrote:
> > Attached is a small patch ("ksh93_tab_completion_choice.diff.txt" ;
> > relative to the current Solaris OS/Net tree, but it should apply to
> > ksh93r cleanly, too) which may be usefull for integration into ksh93r+.
> >
> > The patch changes the behaviour of the TAB completion in emacs mode to
> > preview a list of choices (e.g. equilavent to ESC-'=') instead of doing
> > the completion itself which may be much more usefull when many file name
> > are matching the given pattern (it also contains a comment how to make
> > it slightly "better", however I am not sure (yet) how this can be done
> > easily).
> >
> > Little bit testing with our students showed that they like it more than
> > the current TAB completion... :-)
> >
> > Basically the patch is equivalent to
> > -- snip --
> > function emacs_completion
> > {
> >     if [[ ${.sh.edchar} == "$(printf "\t")" ]] then
> >         .sh.edchar="$(printf "\E=")"
> >         true
> >     fi
> > }
> >
> > trap emacs_completion KEYBD
> > -- snip --
> 
> Actually it could be done better... attached is a 2nd patch
> ("ksh93_tab_tab_gmacs_completion_try2.diff.txt") which also implements
> TAB-TAB completion like in bash3.
> Single TAB now completes the filename either completely - or if that
> isn't possible it's completed to the point where the filenames start to
> differ. TAB-TAB then displays a list of choices. Additionally in "gmacs"
> mode typing TAB on an empty string will try to do the filename
> completion for the whole directory (and TAB-TAB displays all choices
> then). "emacs" mode still behaves as usual, incl. the ability to enter
> the TAB character.
> (note: the previous patch was tested for ~~one week, the current one is
> more or less untested) ...

Attached is now the 3rd version... the only difference to the previous
patch is that I added a way to provide a default editor mode (set to
"gmacs" for the initial ksh93-integration (and to aid the migration of
bash2/3 users to ksh93)). Basically it is an equivalent to the following
ksh93 shell code:
-- snip --
emacs_completion_tab_count=0

function emacs_completion
{
    if [[ ${.sh.edchar} == "$(printf "\t")" ]] then
        emacs_completion_tab_count=$((emacs_completion_tab_count + 1))

        if [ $emacs_completion_tab_count -eq 1 ] ; then
            .sh.edchar="$(printf "\E\E")"
        elif [ $emacs_completion_tab_count -ge 2 ] ; then
            .sh.edchar="$(printf "\E=")"
        fi
    else
        emacs_completion_tab_count=0
    fi
}

trap emacs_completion KEYBD
set -o gmacs
-- snip --

David/April: Are there any objections of making the "gmacs" editor mode
the "default" for both Solaris (for both "ksh93r+" and
ksh93-integration) and Linux ?

----

Bye
Roland

-- 
  __ .  . __
 (o.\ \/ /.o) roland.mainz at nrubsig.org
  \__\/\/__/  MPEG specialist, C&&JAVA&&Sun&&Unix programmer
  /O /==\ O\  TEL +49 641 7950090
 (;O/ \/ \O;)
-------------- next part --------------
Index: lib/libshell/common/edit/emacs.c
===================================================================
--- lib/libshell/common/edit/emacs.c	(revision 222)
+++ lib/libshell/common/edit/emacs.c	(working copy)
@@ -179,6 +179,7 @@
 
 int ed_emacsread(void *context, int fd,char *buff,int scend, int reedit)
 {
+	static unsigned int tab_count = 0;
 	Edit_t *ed = (Edit_t*)context;
 	register int c;
 	register int i;
@@ -306,6 +307,13 @@
 			count = 1;
 		adjust = -1;
 		i = cur;
+
+		/* Count tabs for TAB completion (single TAB or TAB-TAB) */
+		if(c == '\t')
+			tab_count++;
+		else
+			tab_count = 0;
+
 		switch(c)
 		{
 		case cntl('V'):
@@ -327,11 +335,14 @@
 			continue;
 #endif	/* u370 */
 		case '\t':
-			if(cur>0 && cur>=eol && out[cur-1]!='\t' && out[cur-1]!=' ' && ep->ed->sh->nextprompt)
+			if((cur>0 && cur>=eol && out[cur-1]!='\t' && out[cur-1]!=' ' && ep->ed->sh->nextprompt) ||
+			    sh_isoption(SH_GMACS))
 			{
-				ed_ungetchar(ep->ed,ESC);
-				ed_ungetchar(ep->ed,ESC);
-				continue;
+				if (tab_count == 1)
+					ed_ungetchar(ep->ed,cntl('['));	/* like ESC-ESC */
+				else if (tab_count >= 2)
+					ed_ungetchar(ep->ed,'=');	/* like ESC-'=' */
+				goto esc_;
 			}
 		default:
 			if ((eol+1) >= (scend)) /*  will not fit on line */
@@ -578,6 +589,7 @@
 			draw(ep,REFRESH);
 			continue;
 		case cntl('[') :
+esc_:
 			adjust = escape(ep,out,oadjust);
 			continue;
 		case cntl('R') :
Index: lib/libshell/common/sh/init.c
===================================================================
--- lib/libshell/common/sh/init.c	(revision 222)
+++ lib/libshell/common/sh/init.c	(working copy)
@@ -937,6 +937,10 @@
 #if SHOPT_TIMEOUT
 	sh.st.tmout = SHOPT_TIMEOUT;
 #endif /* SHOPT_TIMEOUT */
+/* set (platform-specific default modes) */
+#ifdef SHOPT_DEFAULTEDITMODE
+	sh_onoption(SHOPT_DEFAULTEDITMODE);
+#endif
 	/* initialize jobs table */
 	job_clear();
 	if(argc>0)
Index: lib/libshell/Makefile.com
===================================================================
--- lib/libshell/Makefile.com	(revision 222)
+++ lib/libshell/Makefile.com	(working copy)
@@ -127,6 +127,7 @@
 	-DSHOPT_RAWONLY \
 	-DSHOPT_SUID_EXEC \
 	-DSHOPT_VSH \
+	-DSHOPT_DEFAULTEDITMODE=SH_GMACS \
         -D_BLD_shell \
 	-D_PACKAGE_ast \
 	'-DUSAGE_LICENSE="[-author?David Korn <dgk at research.att.com>][-copyright?Copyright (c) 1982-2006 AT&T Knowledge Ventures][-license?http://www.opensource.org/licenses/cpl1.0.txt][--catalog?libshell]"'