- single KERNEL_VERSION(a,b,c) macro in platform.h

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

diff --git a/coreutils/ln.c b/coreutils/ln.c
index 0640c666611e9a6d5d475643717864a5cac3ad9d..229c682185ef029a0bb80deeacc05b30c23d453e 100644 (file)
--- a/coreutils/ln.c
+++ b/coreutils/ln.c
@@ -2,7 +2,7 @@
 /*
  * Mini ln implementation for busybox
  *
- * Copyright (C) 1999-2003 by Erik Andersen <andersen@codepoet.org>
+ * 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
@@ -21,33 +21,33 @@
  */
 
 /* 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 <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <errno.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)
 {
        int status = EXIT_SUCCESS;
        int flag;
        char *last;
        char *src_name;
        char *src;
+       char *suffix = "~";
        struct stat statbuf;
        int (*link_func)(const char *, const char *);
 
-       flag = bb_getopt_ulflags(argc, argv, "sfn");
+       flag = bb_getopt_ulflags(argc, argv, "sfnbS:", &suffix);
 
        if (argc == optind) {
                bb_show_usage();
@@ -73,15 +73,30 @@ extern int ln_main(int argc, char **argv)
                        free(src_name);
                        src_name = src;
                }
-
-               if (stat(*argv, &statbuf)) {
-                       bb_perror_msg(*argv);
+               if (!(flag & LN_SYMLINK) && stat(*argv, &statbuf)) {
+                       bb_perror_msg("%s", *argv);
                        status = EXIT_FAILURE;
                        free(src_name);
                        continue;
                }
 
-               if (flag & LN_FORCE) {
+               if (flag & LN_BACKUP) {
+                               char *backup;
+                               backup = bb_xasprintf("%s%s", src, suffix);
+                               if (rename(src, backup) < 0 && errno != ENOENT) {
+                                               bb_perror_msg("%s", 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 +104,15 @@ 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_perror_msg("%s", src);
                        status = EXIT_FAILURE;
                }
 
                free(src_name);
-               
+
        } while ((++argv)[1]);
 
        return status;
 }
-
-
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-