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authorRob Landley2005-04-29 22:13:04 +0000
committerRob Landley2005-04-29 22:13:04 +0000
commit3071e2fda3d9a609a00f31418a97fe8174f8b7fc (patch)
tree0291a3cc89f763fbf64253e30f08ebf382efc712 /coreutils/ln.c
parentfdc4c203e54227a2d79fe0a4936ce4bc020e1eff (diff)
downloadbusybox-3071e2fda3d9a609a00f31418a97fe8174f8b7fc.zip
busybox-3071e2fda3d9a609a00f31418a97fe8174f8b7fc.tar.gz
Patch from Matthew S. Wood:
> The following patch adds support for the -S and -b flags to `ln'. These > flags [especially -b] are used extensively in Debian pre and post > installation scripts. Comments from Vladimir Oleynik influenced the final patch, and I also ripped out the in-file changelog since it belongs here. At the time, it said: /* Apr 15, 2004 Matthew S. Wood (mwood@realmsys.com) * * Implement '-b' (backup) flag. * Implement '-S' (backup suffix) flag. * * * Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org) * * Fixed bug involving -n option. Essentially, -n was always in effect. */
Diffstat (limited to 'coreutils/ln.c')
-rw-r--r--coreutils/ln.c32
1 files changed, 24 insertions, 8 deletions
diff --git a/coreutils/ln.c b/coreutils/ln.c
index 885ba61..274e0d0 100644
--- a/coreutils/ln.c
+++ b/coreutils/ln.c
@@ -21,21 +21,20 @@
*/
/* 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)
{
@@ -44,10 +43,11 @@ extern int ln_main(int argc, char **argv)
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();
@@ -80,7 +80,23 @@ extern int ln_main(int argc, char **argv)
continue;
}
- if (flag & LN_FORCE) {
+ if (flag & LN_BACKUP) {
+ char *backup = NULL;
+ bb_xasprintf(&backup, "%s%s", src, suffix);
+ if (rename(src, backup) < 0 && errno != ENOENT) {
+ bb_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);
}