13280: NewImproved handling of colon modifiers w.r.t. paths

ChangeLog

@@ -1,3 +1,9 @@
+2001-02-19  Peter Stephenson  <pws@csr.com>
+
+	* Alexandre: 13280: Doc/Zsh/expn.yo, Src/hist.c, Src/string.c,
+	  Src/system.h:  More sh-like and path-like handling of colon
+	  modifiers.
+
 2001-02-17  Peter Stephenson  <pws@pwstephenson.fsnet.co.uk>
 
 	* unposted: Doc/Zsh/metafaq.yo: site name change from Geoff.

Doc/Zsh/expn.yo

@@ -202,16 +202,19 @@ noted.
 
 startitem()
 item(tt(h))(
-Remove a trailing pathname component, leaving the head.
+Remove a trailing pathname component, leaving the head.  This works
+like `tt(dirname)'.
 )
 item(tt(r))(
-Remove a trailing suffix of the form `tt(.)var(xxx)', leaving the basename.
+Remove a filename extension of the form `tt(.)var(xxx)', leaving
+the root name.
 )
 item(tt(e))(
-Remove all but the suffix.
+Remove all but the extension.
 )
 item(tt(t))(
-Remove all leading pathname components, leaving the tail.
+Remove all leading pathname components, leaving the tail.  This works
+like `tt(basename)'.
 )
 item(tt(p))(
 Print the new command but do not execute it.  Only works with history

Src/hist.c

@@ -1350,28 +1350,45 @@ hcomsearch(char *str)
 int
 remtpath(char **junkptr)
 {
-    char *str = *junkptr, *remcut;
+    char *str = strend(*junkptr);
 
-    if ((remcut = strrchr(str, '/'))) {
-	if (str != remcut)
-	    *remcut = '\0';
-	else
-	    str[1] = '\0';
-	return 1;
+    /* ignore trailing slashes */
+    while (str >= *junkptr && IS_DIRSEP(*str))
+	--str;
+    /* skip filename */
+    while (str >= *junkptr && !IS_DIRSEP(*str))
+	--str;
+    if (str < *junkptr) {
+	*junkptr = dupstring (".");
+	return 0;
     }
-    return 0;
+    /* repeated slashes are considered like a single slash */
+    while (str > *junkptr && IS_DIRSEP(str[-1]))
+	--str;
+    /* never erase the root slash */
+    if (str == *junkptr) {
+	++str;
+	/* Leading doubled slashes (`//') have a special meaning on cygwin
+	   and some old flavor of UNIX, so we do not assimilate them to
+	   a single slash.  However a greater number is ok to squeeze. */
+	if (IS_DIRSEP(*str) && !IS_DIRSEP(str[1]))
+	    ++str;
+    }
+    *str = '\0';
+    return 1;
 }
 
 /**/
 int
 remtext(char **junkptr)
 {
-    char *str = *junkptr, *remcut;
+    char *str;
 
-    if ((remcut = strrchr(str, '.')) && remcut != str) {
-	*remcut = '\0';
-	return 1;
-    }
+    for (str = strend(*junkptr); str >= *junkptr && !IS_DIRSEP(*str); --str)
+	if (*str == '.') {
+	    *str = '\0';
+	    return 1;
+	}
     return 0;
 }
 
@@ -1379,12 +1396,15 @@ remtext(char **junkptr)
 int
 rembutext(char **junkptr)
 {
-    char *str = *junkptr, *remcut;
+    char *str;
 
-    if ((remcut = strrchr(str, '.')) && remcut != str) {
-	*junkptr = dupstring(remcut + 1);	/* .xx or xx? */
-	return 1;
-    }
+    for (str = strend(*junkptr); str >= *junkptr && !IS_DIRSEP(*str); --str)
+	if (*str == '.') {
+	    *junkptr = dupstring(str + 1); /* .xx or xx? */
+	    return 1;
+	}
+    /* no extension */
+    *junkptr = dupstring ("");
     return 0;
 }
 
@@ -1392,13 +1412,20 @@ rembutext(char **junkptr)
 mod_export int
 remlpaths(char **junkptr)
 {
-    char *str = *junkptr, *remcut;
+    char *str = strend(*junkptr);
 
-    if ((remcut = strrchr(str, '/'))) {
-	*remcut = '\0';
-	*junkptr = dupstring(remcut + 1);
-	return 1;
+    if (IS_DIRSEP(*str)) {
+	/* remove trailing slashes */
+	while (str >= *junkptr && IS_DIRSEP(*str))
+	    --str;
+	str[1] = '\0';
     }
+    for (; str >= *junkptr; --str)
+	if (IS_DIRSEP(*str)) {
+	    *str = '\0';
+	    *junkptr = dupstring(str + 1);
+	    return 1;
+	}
     return 0;
 }
 

Src/string.c

@@ -79,7 +79,7 @@ zhtricat(char const *s1, char const *s2, char const *s3)
     char *ptr;
     size_t l1 = strlen(s1);
     size_t l2 = strlen(s2);
-    
+
     ptr = (char *)zhalloc(l1 + l2 + strlen(s3) + 1);
     strcpy(ptr, s1);
     strcpy(ptr + l1, s2);
@@ -133,3 +133,15 @@ appstr(char *base, char const *append)
 {
     return strcat(realloc(base, strlen(base) + strlen(append) + 1), append);
 }
+
+/* Return a pointer to the last character of a string,
+   unless the string is empty. */
+
+/**/
+mod_export char *
+strend(char *str)
+{
+    if (*str == '\0')
+	return str;
+    return str + strlen (str) - 1;
+}

Src/system.h

@@ -657,3 +657,9 @@ extern short ospeed;
 #ifndef MAILDIR_SUPPORT
 #define mailstat(X,Y) stat(X,Y)
 #endif
+
+#ifdef __CYGWIN__
+# define IS_DIRSEP(c) ((c) == '/' || (c) == '\\')
+#else
+# define IS_DIRSEP(c) ((c) == '/')
+#endif