Re: Tip of the day: some glob selectors

[Peter Stephenson <pws@xxxxxxx>]

Peter Stephenson wrote:
> I wonder if it's a useful addition to allow
> 
> ls -l *(+nt)
> explorer ~(+cyg)
> 
> as a shorthand?  The + would swallow up, say, all characters that can
> appear in an identifier (alphanumerics plus underscore) and save it as
> the command.  This would mean you could even chain them: *(+nt+cyg).
> With arguments you're stuck with the long syntax, however.

This is the patch, if anyone is interested.

Index: Doc/Zsh/expn.yo
===================================================================
RCS file: /cvsroot/zsh/zsh/Doc/Zsh/expn.yo,v
retrieving revision 1.49
diff -u -r1.49 expn.yo
--- Doc/Zsh/expn.yo	6 Apr 2004 09:26:50 -0000	1.49
+++ Doc/Zsh/expn.yo	10 Jan 2005 10:29:00 -0000
@@ -1739,7 +1739,8 @@
 permission, and for which other users don't have read or execute
 permission.
 )
-item(tt(e)var(string))(
+xitem(tt(e)var(string))
+item(tt(PLUS())var(cmd))(
 The var(string) will be executed as shell code.  The filename will be
 included in the list if and only if the code returns a zero status (usually
 the status of the last command).  The first character after the `tt(e)'
@@ -1762,6 +1763,19 @@
 the expression `tt(*(e:'reply=(${REPLY}{1,2})':))' will cause the words
 `tt(lonely1 lonely2)' to be inserted into the command line.  Note the
 quotation marks.
+
+The form tt(PLUS())var(cmd) has the same effect, but no delimiters appear
+around var(cmd).  Instead, var(cmd) is taken as the longest sequence of
+characters following the tt(PLUS()) that are alphanumeric or underscore.
+Typically var(cmd) will be the name of a shell function that contains the
+appropriate test.  For example,
+
+example(nt() { [[ $REPLY -nt $NTREF ]] }
+NTREF=reffile
+ls -l *(+nt))
+
+lists all files in the directory that have been modified more recently than
+tt(reffile).
 )
 item(tt(d)var(dev))(
 files on the device var(dev)
Index: Src/glob.c
===================================================================
RCS file: /cvsroot/zsh/zsh/Src/glob.c,v
retrieving revision 1.37
diff -u -r1.37 glob.c
--- Src/glob.c	26 Oct 2004 17:20:29 -0000	1.37
+++ Src/glob.c	10 Jan 2005 10:29:01 -0000
@@ -1426,22 +1426,43 @@
 		    s++;
 		    break;
 		}
+		case '+':
 		case 'e':
 		{
-		    char sav, *tt = get_strarg(s);
+		    char sav, *tt;
+		    int plus;
 
-		    if (!*tt) {
-			zerr("missing end of string", NULL, 0);
+		    if (s[-1] == '+') {
+			plus = 0;
+			tt = s;
+			while (iident(*tt))
+			    tt++;
+			if (tt == s)
+			{
+			    zerr("missing identifier after `+'", NULL, 0);
+			    tt = NULL;
+			}
+		    } else {
+			plus = 1;
+			tt = get_strarg(s);
+			if (!*tt)
+			{
+			    zerr("missing end of string", NULL, 0);
+			    tt = NULL;
+			}
+		    }
+
+		    if (tt == NULL) {
 			data = 0;
 		    } else {
 			sav = *tt;
 			*tt = '\0';
 			func = qualsheval;
-			sdata = dupstring(s + 1);
+			sdata = dupstring(s + plus);
 			untokenize(sdata);
 			*tt = sav;
 			if (sav)
-			    s = tt + 1;
+			    s = tt + plus;
 			else
 			    s = tt;
 		    }

-- 
Peter Stephenson <pws@xxxxxxx>                  Software Engineer
CSR PLC, Churchill House, Cambridge Business Park, Cowley Road
Cambridge, CB4 0WZ, UK                          Tel: +44 (0)1223 692070


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