From 33d1439fdbf56ec100dbddfa9f7472a0da59d183 Mon Sep 17 00:00:00 2001
From: Peter Stephenson <p.w.stephenson@ntlworld.com>
Date: Fri, 2 Jan 2015 21:32:51 +0000
Subject: users/19667: whence -S shows intermediate steps in symlink expansion

---
 Src/builtin.c | 12 +++++------
 Src/utils.c   | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 66 insertions(+), 13 deletions(-)

(limited to 'Src')

diff --git a/Src/builtin.c b/Src/builtin.c
index 264169cb4..47d1aa06d 100644
--- a/Src/builtin.c
+++ b/Src/builtin.c
@@ -119,7 +119,7 @@ static struct builtin builtins[] =
     BUILTIN("times", BINF_PSPECIAL, bin_times, 0, 0, 0, NULL, NULL),
     BUILTIN("trap", BINF_PSPECIAL | BINF_HANDLES_OPTS, bin_trap, 0, -1, 0, NULL, NULL),
     BUILTIN("true", 0, bin_true, 0, -1, 0, NULL, NULL),
-    BUILTIN("type", 0, bin_whence, 0, -1, 0, "ampfsw", "v"),
+    BUILTIN("type", 0, bin_whence, 0, -1, 0, "ampfsSw", "v"),
     BUILTIN("typeset", BINF_PLUSOPTS | BINF_MAGICEQUALS | BINF_PSPECIAL, bin_typeset, 0, -1, 0, "AE:%F:%HL:%R:%TUZ:%afghi:%klprtuxmz", NULL),
     BUILTIN("umask", 0, bin_umask, 0, 1, 0, "S", NULL),
     BUILTIN("unalias", 0, bin_unhash, 1, -1, 0, "ms", "a"),
@@ -128,7 +128,7 @@ static struct builtin builtins[] =
     BUILTIN("unset", BINF_PSPECIAL, bin_unset, 1, -1, 0, "fmv", NULL),
     BUILTIN("unsetopt", 0, bin_setopt, 0, -1, BIN_UNSETOPT, NULL, NULL),
     BUILTIN("wait", 0, bin_fg, 0, -1, BIN_WAIT, NULL, NULL),
-    BUILTIN("whence", 0, bin_whence, 0, -1, 0, "acmpvfsw", NULL),
+    BUILTIN("whence", 0, bin_whence, 0, -1, 0, "acmpvfsSw", NULL),
     BUILTIN("where", 0, bin_whence, 0, -1, 0, "pmsw", "ca"),
     BUILTIN("which", 0, bin_whence, 0, -1, 0, "ampsw", "c"),
     BUILTIN("zmodload", 0, bin_zmodload, 0, -1, 0, "AFRILP:abcfdilmpue", NULL),
@@ -3331,8 +3331,8 @@ bin_whence(char *nam, char **argv, Options ops, int func)
 			if (v && !csh)
 			    zputs(*argv, stdout), fputs(" is ", stdout);
 			zputs(buf, stdout);
-			if (OPT_ISSET(ops,'s'))
-			    print_if_link(buf);
+			if (OPT_ISSET(ops,'s') || OPT_ISSET(ops, 'S'))
+			    print_if_link(buf, OPT_ISSET(ops, 'S'));
 			fputc('\n', stdout);
 		    }
 		    informed = 1;
@@ -3352,8 +3352,8 @@ bin_whence(char *nam, char **argv, Options ops, int func)
 		if (v && !csh)
 		    zputs(*argv, stdout), fputs(" is ", stdout);
 		zputs(cnam, stdout);
-		if (OPT_ISSET(ops,'s'))
-		    print_if_link(cnam);
+		if (OPT_ISSET(ops,'s') || OPT_ISSET(ops,'S'))
+		    print_if_link(cnam, OPT_ISSET(ops,'S'));
 		fputc('\n', stdout);
 	    }
 	} else {
diff --git a/Src/utils.c b/Src/utils.c
index 893a8ca02..2b2a815a8 100644
--- a/Src/utils.c
+++ b/Src/utils.c
@@ -719,7 +719,7 @@ slashsplit(char *s)
 
 /**/
 static int
-xsymlinks(char *s)
+xsymlinks(char *s, int full)
 {
     char **pp, **opp;
     char xbuf2[PATH_MAX*3], xbuf3[PATH_MAX*2];
@@ -758,14 +758,49 @@ xsymlinks(char *s)
 	} else {
 	    ret = 1;
 	    metafy(xbuf3, t0, META_NOALLOC);
+	    if (!full) {
+		/*
+		 * If only one expansion requested, ensure the
+		 * full path is in xbuf.
+		 */
+		zulong len = xbuflen;
+		if (*xbuf3 == '/')
+		    strcpy(xbuf, xbuf3);
+		else if ((len += strlen(xbuf3) + 1) < sizeof(xbuf)) {
+		    strcpy(xbuf + xbuflen, "/");
+		    strcpy(xbuf + xbuflen + 1, xbuf3);
+		} else {
+		    *xbuf = 0;
+		    ret = -1;
+		    break;
+		}
+
+		while (*++pp) {
+		    zulong newlen = len + strlen(*pp) + 1;
+		    if (newlen < sizeof(xbuf)) {
+			strcpy(xbuf + len, "/");
+			strcpy(xbuf + len + 1, *pp);
+			len = newlen;
+		    } else {
+			*xbuf = 01;
+			ret = -1;
+			break;
+		    }
+		}
+		/*
+		 * No need to update xbuflen, we're finished
+		 * the expansion (for now).
+		 */
+		break;
+	    }
 	    if (*xbuf3 == '/') {
 		strcpy(xbuf, "");
-		if (xsymlinks(xbuf3 + 1) < 0)
+		if (xsymlinks(xbuf3 + 1, 0) < 0)
 		    ret = -1;
 		else
 		    xbuflen = strlen(xbuf);
 	    } else
-		if (xsymlinks(xbuf3) < 0)
+		if (xsymlinks(xbuf3, 0) < 0)
 		    ret = -1;
 		else
 		    xbuflen = strlen(xbuf);
@@ -787,7 +822,7 @@ xsymlink(char *s)
     if (*s != '/')
 	return NULL;
     *xbuf = '\0';
-    if (xsymlinks(s + 1) < 0)
+    if (xsymlinks(s + 1, 1) < 0)
 	zwarn("path expansion failed, using root directory");
     if (!*xbuf)
 	return ztrdup("/");
@@ -796,12 +831,30 @@ xsymlink(char *s)
 
 /**/
 void
-print_if_link(char *s)
+print_if_link(char *s, int all)
 {
     if (*s == '/') {
 	*xbuf = '\0';
-	if (xsymlinks(s + 1) > 0)
-	    printf(" -> "), zputs(*xbuf ? xbuf : "/", stdout);
+	if (all) {
+	    char *start = s + 1;
+	    char xbuflink[PATH_MAX];
+	    for (;;) {
+		if (xsymlinks(start, 0) > 0) {
+		    printf(" -> ");
+		    zputs(*xbuf ? xbuf : "/", stdout);
+		    if (!*xbuf)
+			break;
+		    strcpy(xbuflink, xbuf);
+		    start = xbuflink + 1;
+		    *xbuf = '\0';
+		} else {
+		    break;
+		}
+	    }
+	} else {
+	    if (xsymlinks(s + 1, 1) > 0)
+		printf(" -> "), zputs(*xbuf ? xbuf : "/", stdout);
+	}
     }
 }
 
-- 
cgit 1.4.1