26748: c modifier to add command path

ChangeLog

@@ -1,5 +1,8 @@
 2009-03-23  Peter Stephenson  <pws@csr.com>
 
+	* 26748: Doc/Zsh/expn.yo, Src/hist.c, Src/subst.c: c modifier
+	to add command path.
+
 	* 26767: Src/utils.c: 26763 created file descriptor leak.
 
 2009-03-20  Peter Stephenson  <p.w.stephenson@ntlworld.com>
@@ -11469,5 +11472,5 @@
 
 *****************************************************
 * This is used by the shell to define $ZSH_PATCHLEVEL
-* $Revision: 1.4631 $
+* $Revision: 1.4632 $
 *****************************************************

Doc/Zsh/expn.yo

@@ -219,6 +219,8 @@ startitem()
 item(tt(a))(
 Turn a file name into an absolute path:  prepends the current directory,
 if necessary, and resolves any use of `tt(..)' and `tt(.)' in the path.
+Note that the transformation takes place even if the file or any
+intervening directories do not exist.
 )
 item(tt(A))(
 As `tt(a)', but also resolve use of symbolic links where possible.
@@ -226,6 +228,13 @@ Note that resolution of `tt(..)' occurs em(before) resolution of symbolic
 links.  This call is equivalent to tt(a) unless your system has the
 tt(realpath) system call (modern systems do).
 )
+item(tt(c))(
+Resolve a command name into an absolute path by searching the command
+path given by the tt(PATH) variable.  This does not work for commands
+containing directory parts.  Note also that this does not usually work as
+a glob qualifier unless a file of the same name is found in the
+current directory.
+)
 item(tt(e))(
 Remove all but the extension.
 )

Src/hist.c

@@ -638,6 +638,13 @@ histsubchar(int c)
 		    return -1;
 		}
 		break;
+	    case 'c':
+		if (!(sline = equalsubstr(sline, 0, 0))) {
+		    herrflush();
+		    zerr("modifier failed: c");
+		    return -1;
+		}
+		break;
 	    case 'h':
 		if (!remtpath(&sline)) {
 		    herrflush();

Src/subst.c

@@ -539,12 +539,43 @@ filesub(char **namptr, int assign)
     }
 }
 
+#define isend(c) ( !(c) || (c)=='/' || (c)==Inpar || (assign && (c)==':') )
+#define isend2(c) ( !(c) || (c)==Inpar || (assign && (c)==':') )
+
+/*
+ * do =foo substitution, or equivalent.
+ * on entry, str should point to the "foo".
+ * if assign, this is in an assignment
+ * if nomatch, report hard error on failure.
+ * if successful, returns the expansion, else NULL.
+ */
+
+/**/
+char *
+equalsubstr(char *str, int assign, int nomatch)
+{
+    char *pp, *cnam, *cmdstr, *ret;
+
+    for (pp = str; !isend2(*pp); pp++)
+	;
+    cmdstr = dupstrpfx(str, pp-str);
+    untokenize(cmdstr);
+    remnulargs(cmdstr);
+    if (!(cnam = findcmd(cmdstr, 1))) {
+	if (nomatch)
+	    zerr("%s not found", cmdstr);
+	return NULL;
+    }
+    ret = dupstring(cnam);
+    if (*pp)
+	ret = dyncat(ret, pp);
+    return ret;
+}
+
 /**/
 mod_export int
 filesubstr(char **namptr, int assign)
 {
-#define isend(c) ( !(c) || (c)=='/' || (c)==Inpar || (assign && (c)==':') )
-#define isend2(c) ( !(c) || (c)==Inpar || (assign && (c)==':') )
     char *str = *namptr;
 
     if (*str == Tilde && str[1] != '=' && str[1] != Equals) {
@@ -606,27 +637,17 @@ filesubstr(char **namptr, int assign)
 	    return 1;
 	}
     } else if (*str == Equals && isset(EQUALS) && str[1]) {   /* =foo */
-	char *pp, *cnam, *cmdstr, *str1 = str+1;
-
-	for (pp = str1; !isend2(*pp); pp++)
-	    ;
-	cmdstr = dupstrpfx(str1, pp-str1);
-	untokenize(cmdstr);
-	remnulargs(cmdstr);
-	if (!(cnam = findcmd(cmdstr, 1))) {
-	    if (isset(NOMATCH))
-		zerr("%s not found", cmdstr);
-	    return 0;
+	char *expn = equalsubstr(str+1, assign, isset(NOMATCH));
+	if (expn) {
+	    *namptr = expn;
+	    return 1;
 	}
-	*namptr = dupstring(cnam);
-	if (*pp)
-	    *namptr = dyncat(*namptr, pp);
-	return 1;
     }
     return 0;
+}
+
 #undef isend
 #undef isend2
-}
 
 /**/
 static char *
@@ -3201,6 +3222,7 @@ modify(char **str, char **ptr)
 	    switch (**ptr) {
             case 'a':
             case 'A':
+	    case 'c':
 	    case 'h':
 	    case 'r':
 	    case 'e':
@@ -3345,6 +3367,13 @@ modify(char **str, char **ptr)
 		    case 'A':
 			chrealpath(&copy);
 			break;
+		    case 'c':
+		    {
+			char *copy2 = equalsubstr(copy, 0, 0);
+			if (copy2)
+			    copy = copy2;
+			break;
+		    }
 		    case 'h':
 			remtpath(&copy);
 			break;
@@ -3410,6 +3439,13 @@ modify(char **str, char **ptr)
 		case 'A':
 		    chrealpath(str);
 		    break;
+		case 'c':
+		{
+		    char *copy2 = equalsubstr(*str, 0, 0);
+		    if (copy2)
+			*str = copy2;
+		    break;
+		}
 		case 'h':
 		    remtpath(str);
 		    break;