X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=coreutils%2Fln.c;h=eb7171959cbe62b479753124fb817eda6df90309;hb=eab40e58858d01372b5d74b7330be2d7b1c7fc75;hp=885ba61dbd9c3febc70fbb51605135f8cd077042;hpb=c7bda1ce659294d6e22c06e087f6f265983c7578;p=oweals%2Fbusybox.git

diff --git a/coreutils/ln.c b/coreutils/ln.c
index 885ba61db..eb7171959 100644
--- a/coreutils/ln.c
+++ b/coreutils/ln.c
@@ -4,50 +4,37 @@
  *
  * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
  *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
  */
 
 /* BB_AUDIT SUSv3 compliant */
-/* BB_AUDIT GNU options missing: -b, -d, -F, -i, -S, and -v. */
+/* BB_AUDIT GNU options missing: -d, -F, -i, and -v. */
 /* http://www.opengroup.org/onlinepubs/007904975/utilities/ln.html */
 
-/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
- *
- * Fixed bug involving -n option.  Essentially, -n was always in effect.
- */
+#include "libbb.h"
+
+/* This is a NOEXEC applet. Be very careful! */
 
-#include <stdlib.h>
-#include <unistd.h>
-#include "busybox.h"
 
 #define LN_SYMLINK          1
 #define LN_FORCE            2
 #define LN_NODEREFERENCE    4
+#define LN_BACKUP           8
+#define LN_SUFFIX           16
 
-extern int ln_main(int argc, char **argv)
+int ln_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int ln_main(int argc, char **argv)
 {
 	int status = EXIT_SUCCESS;
 	int flag;
 	char *last;
 	char *src_name;
 	char *src;
+	char *suffix = (char*)"~";
 	struct stat statbuf;
 	int (*link_func)(const char *, const char *);
 
-	flag = bb_getopt_ulflags(argc, argv, "sfn");
+	flag = getopt32(argv, "sfnbS:", &suffix);
 
 	if (argc == optind) {
 		bb_show_usage();
@@ -58,7 +45,7 @@ extern int ln_main(int argc, char **argv)
 
 	if (argc == optind + 1) {
 		*--argv = last;
-		last = bb_get_last_path_component(bb_xstrdup(last));
+		last = bb_get_last_path_component_strip(xstrdup(last));
 	}
 
 	do {
@@ -66,21 +53,41 @@ extern int ln_main(int argc, char **argv)
 		src = last;
 
 		if (is_directory(src,
-						 (flag & LN_NODEREFERENCE) ^ LN_NODEREFERENCE,
-						 NULL)) {
-			src_name = bb_xstrdup(*argv);
-			src = concat_path_file(src, bb_get_last_path_component(src_name));
+		                (flag & LN_NODEREFERENCE) ^ LN_NODEREFERENCE,
+		                NULL)
+		) {
+			src_name = xstrdup(*argv);
+			src = concat_path_file(src, bb_get_last_path_component_strip(src_name));
 			free(src_name);
 			src_name = src;
 		}
 		if (!(flag & LN_SYMLINK) && stat(*argv, &statbuf)) {
-			bb_perror_msg(*argv);
-			status = EXIT_FAILURE;
-			free(src_name);
-			continue;
+			// coreutils: "ln dangling_symlink new_hardlink" works
+			if (lstat(*argv, &statbuf) || !S_ISLNK(statbuf.st_mode)) {
+				bb_simple_perror_msg(*argv);
+				status = EXIT_FAILURE;
+				free(src_name);
+				continue;
+			}
 		}
 
-		if (flag & LN_FORCE) {
+		if (flag & LN_BACKUP) {
+			char *backup;
+			backup = xasprintf("%s%s", src, suffix);
+			if (rename(src, backup) < 0 && errno != ENOENT) {
+				bb_simple_perror_msg(src);
+				status = EXIT_FAILURE;
+				free(backup);
+				continue;
+			}
+			free(backup);
+			/*
+			 * When the source and dest are both hard links to the same
+			 * inode, a rename may succeed even though nothing happened.
+			 * Therefore, always unlink().
+			 */
+			unlink(src);
+		} else if (flag & LN_FORCE) {
 			unlink(src);
 		}
 
@@ -90,7 +97,7 @@ extern int ln_main(int argc, char **argv)
 		}
 
 		if (link_func(*argv, src) != 0) {
-			bb_perror_msg(src);
+			bb_simple_perror_msg(src);
 			status = EXIT_FAILURE;
 		}