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| author | Rob Landley <rob@landley.net> | 2005-04-29 22:13:04 +0000 |
|---|---|---|
| committer | Rob Landley <rob@landley.net> | 2005-04-29 22:13:04 +0000 |
| commit | 3071e2fda3d9a609a00f31418a97fe8174f8b7fc (patch) | |
| tree | 0291a3cc89f763fbf64253e30f08ebf382efc712 /coreutils/ln.c | |
| parent | fdc4c203e54227a2d79fe0a4936ce4bc020e1eff (diff) | |
| download | 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.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/coreutils/ln.c b/coreutils/ln.c index 885ba61db..274e0d06c 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); } |