1 /* vi: set sw=4 ts=4: */
3 * Mini readlink implementation for busybox
5 * Copyright (C) 2000,2001 Matt Kraai <kraai@alumni.carnegiemellon.edu>
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
10 //usage:#define readlink_trivial_usage
11 //usage: IF_FEATURE_READLINK_FOLLOW("[-fnv] ") "FILE"
12 //usage:#define readlink_full_usage "\n\n"
13 //usage: "Display the value of a symlink"
14 //usage: IF_FEATURE_READLINK_FOLLOW( "\n"
15 //usage: "\n -f Canonicalize by following all symlinks"
16 //usage: "\n -n Don't add newline"
17 //usage: "\n -v Verbose"
23 * # readlink --version
24 * readlink (GNU coreutils) 6.10
27 * canonicalize by following every symlink in
28 * every component of the given name recursively;
29 * all but the last component must exist
30 * -e, --canonicalize-existing
31 * canonicalize by following every symlink in
32 * every component of the given name recursively,
33 * all components must exist
34 * -m, --canonicalize-missing
35 * canonicalize by following every symlink in
36 * every component of the given name recursively,
37 * without requirements on components existence
38 * -n, --no-newline do not output the trailing newline
39 * -q, --quiet, -s, --silent suppress most error messages
40 * -v, --verbose report error messages
42 * bbox supports: -f (partially) -n -v (fully), -q -s (accepts but ignores)
43 * Note: we export the -f flag, but our -f behaves like coreutils' -e.
44 * Unfortunately, there isn't a C lib function we can leverage to get this
45 * behavior which means we'd have to implement the full stack ourselves :(.
48 int readlink_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
49 int readlink_main(int argc UNUSED_PARAM, char **argv)
54 IF_FEATURE_READLINK_FOLLOW(
56 /* We need exactly one non-option argument. */
57 opt_complementary = "=1";
58 opt = getopt32(argv, "fnvsq");
61 IF_NOT_FEATURE_READLINK_FOLLOW(
62 const unsigned opt = 0;
63 if (argc != 2) bb_show_usage();
67 /* compat: coreutils readlink reports errors silently via exit code */
68 if (!(opt & 4)) /* not -v */
69 logmode = LOGMODE_NONE;
71 if (opt & 1) { /* -f */
72 buf = xmalloc_realpath(fname);
74 buf = xmalloc_readlink_or_warn(fname);
79 printf((opt & 2) ? "%s" : "%s\n", buf);
81 if (ENABLE_FEATURE_CLEAN_UP)
84 fflush_stdout_and_exit(EXIT_SUCCESS);