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	niro	816	/* 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	niro	984	/*
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	niro	816	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	niro	984	IF_FEATURE_READLINK_FOLLOW(
42	niro	816	unsigned opt;
43			/* We need exactly one non-option argument. */
44			opt_complementary = "=1";
45	niro	984	opt = getopt32(argv, "fnvsq");
46	niro	816	fname = argv[optind];
47			)
48	niro	984	IF_NOT_FEATURE_READLINK_FOLLOW(
49	niro	816	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	niro	984	if (!(opt & 4)) /* not -v */
56			logmode = LOGMODE_NONE;
57	niro	816
58	niro	984	if (opt & 1) { /* -f */
59	niro	816	buf = realpath(fname, pathbuf);
60			} else {
61			buf = xmalloc_readlink_or_warn(fname);
62			}
63
64			if (!buf)
65			return EXIT_FAILURE;
66	niro	984	printf((opt & 2) ? "%s" : "%s\n", buf);
67	niro	816
68			if (ENABLE_FEATURE_CLEAN_UP && !opt)
69			free(buf);
70
71			fflush_stdout_and_exit(EXIT_SUCCESS);
72			}