busybox/coreutils/readlink.c

/* vi: set sw=4 ts=4: */
/*
 * Mini readlink implementation for busybox
 *
 * Copyright (C) 2000,2001 Matt Kraai <kraai@alumni.carnegiemellon.edu>
 *
 * Licensed under GPL v2 or later, see file LICENSE in this tarball for details.
 */
#include "libbb.h"

/*
 * # readlink --version
 * readlink (GNU coreutils) 6.10
 * # readlink --help
 *   -f, --canonicalize
 *      canonicalize by following every symlink in
 *      every component of the given name recursively;
 *      all but the last component must exist
 *   -e, --canonicalize-existing
 *      canonicalize by following every symlink in
 *      every component of the given name recursively,
 *      all components must exist
 *   -m, --canonicalize-missing
 *      canonicalize by following every symlink in
 *      every component of the given name recursively,
 *      without requirements on components existence
 *   -n, --no-newline              do not output the trailing newline
 *   -q, --quiet, -s, --silent     suppress most error messages
 *   -v, --verbose                 report error messages
 *
 * bbox supports: -f -n -v (fully), -q -s (accepts but ignores)
 */

int readlink_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int readlink_main(int argc UNUSED_PARAM, char **argv)
{
	char *buf;
	char *fname;
	char pathbuf[PATH_MAX];

	IF_FEATURE_READLINK_FOLLOW(
		unsigned opt;
		/* We need exactly one non-option argument.  */
		opt_complementary = "=1";
		opt = getopt32(argv, "fnvsq");
		fname = argv[optind];
	)
	IF_NOT_FEATURE_READLINK_FOLLOW(
		const unsigned opt = 0;
		if (argc != 2) bb_show_usage();
		fname = argv[1];
	)

	/* compat: coreutils readlink reports errors silently via exit code */
	if (!(opt & 4)) /* not -v */
		logmode = LOGMODE_NONE;

	if (opt & 1) { /* -f */
		buf = realpath(fname, pathbuf);
	} else {
		buf = xmalloc_readlink_or_warn(fname);
	}

	if (!buf)
		return EXIT_FAILURE;
	printf((opt & 2) ? "%s" : "%s\n", buf);

	if (ENABLE_FEATURE_CLEAN_UP && !opt)
		free(buf);

	fflush_stdout_and_exit(EXIT_SUCCESS);
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Mini readlink implementation for busybox
4	*
5	* Copyright (C) 2000,2001 Matt Kraai <kraai@alumni.carnegiemellon.edu>
6	*
7	* Licensed under GPL v2 or later, see file LICENSE in this tarball for details.
8	*/
9	#include "libbb.h"
10
11	/*
12	* # readlink --version
13	* readlink (GNU coreutils) 6.10
14	* # readlink --help
15	* -f, --canonicalize
16	* canonicalize by following every symlink in
17	* every component of the given name recursively;
18	* all but the last component must exist
19	* -e, --canonicalize-existing
20	* canonicalize by following every symlink in
21	* every component of the given name recursively,
22	* all components must exist
23	* -m, --canonicalize-missing
24	* canonicalize by following every symlink in
25	* every component of the given name recursively,
26	* without requirements on components existence
27	* -n, --no-newline do not output the trailing newline
28	* -q, --quiet, -s, --silent suppress most error messages
29	* -v, --verbose report error messages
30	*
31	* bbox supports: -f -n -v (fully), -q -s (accepts but ignores)
32	*/
33
34	int readlink_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
35	int readlink_main(int argc UNUSED_PARAM, char **argv)
36	{
37	char *buf;
38	char *fname;
39	char pathbuf[PATH_MAX];
40
41	IF_FEATURE_READLINK_FOLLOW(
42	unsigned opt;
43	/* We need exactly one non-option argument. */
44	opt_complementary = "=1";
45	opt = getopt32(argv, "fnvsq");
46	fname = argv[optind];
47	)
48	IF_NOT_FEATURE_READLINK_FOLLOW(
49	const unsigned opt = 0;
50	if (argc != 2) bb_show_usage();
51	fname = argv[1];
52	)
53
54	/* compat: coreutils readlink reports errors silently via exit code */
55	if (!(opt & 4)) /* not -v */
56	logmode = LOGMODE_NONE;
57
58	if (opt & 1) { /* -f */
59	buf = realpath(fname, pathbuf);
60	} else {
61	buf = xmalloc_readlink_or_warn(fname);
62	}
63
64	if (!buf)
65	return EXIT_FAILURE;
66	printf((opt & 2) ? "%s" : "%s\n", buf);
67
68	if (ENABLE_FEATURE_CLEAN_UP && !opt)
69	free(buf);
70
71	fflush_stdout_and_exit(EXIT_SUCCESS);
72	}