ls: do not follow links with -s (closes bug 33),

[oweals/busybox.git] / coreutils / ln.c

diff --git a/coreutils/ln.c b/coreutils/ln.c
index 0640c666611e9a6d5d475643717864a5cac3ad9d..eb7171959cbe62b479753124fb817eda6df90309 100644 (file)
--- a/coreutils/ln.c
+++ b/coreutils/ln.c
@@ -2,52 +2,39 @@
 /*
  * Mini ln implementation for busybox
  *
- * Copyright (C) 1999-2003 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
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
  *
+ * 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 {
@@ -66,22 +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 (stat(*argv, &statbuf)) {
-                       bb_perror_msg(*argv);
-                       status = EXIT_FAILURE;
-                       free(src_name);
-                       continue;
+               if (!(flag & LN_SYMLINK) && stat(*argv, &statbuf)) {
+                       // 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);
                }
 
@@ -89,25 +95,15 @@ extern int ln_main(int argc, char **argv)
                if (flag & LN_SYMLINK) {
                        link_func = symlink;
                }
-               
+
                if (link_func(*argv, src) != 0) {
-                       bb_perror_msg(src);
+                       bb_simple_perror_msg(src);
                        status = EXIT_FAILURE;
                }
 
                free(src_name);
-               
+
        } while ((++argv)[1]);
 
        return status;
 }
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