*
* Copyright (C) 2000,2001 Matt Kraai <kraai@alumni.carnegiemellon.edu>
*
- * Licensed under GPL v2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+//config:config READLINK
+//config: bool "readlink (3.6 kb)"
+//config: default y
+//config: help
+//config: This program reads a symbolic link and returns the name
+//config: of the file it points to
+//config:
+//config:config FEATURE_READLINK_FOLLOW
+//config: bool "Enable canonicalization by following all symlinks (-f)"
+//config: default y
+//config: depends on READLINK
+//config: help
+//config: Enable the readlink option (-f).
+
+//applet:IF_READLINK(APPLET_NOFORK(readlink, readlink, BB_DIR_USR_BIN, BB_SUID_DROP, readlink))
+
+//kbuild:lib-$(CONFIG_READLINK) += readlink.o
+
+//usage:#define readlink_trivial_usage
+//usage: IF_FEATURE_READLINK_FOLLOW("[-fnv] ") "FILE"
+//usage:#define readlink_full_usage "\n\n"
+//usage: "Display the value of a symlink"
+//usage: IF_FEATURE_READLINK_FOLLOW( "\n"
+//usage: "\n -f Canonicalize by following all symlinks"
+//usage: "\n -n Don't add newline"
+//usage: "\n -v Verbose"
+//usage: )
-#include <getopt.h>
#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 (partially) -n -v (fully), -q -s (accepts but ignores)
+ * Note: we export the -f flag, but our -f behaves like coreutils' -e.
+ * Unfortunately, there isn't a C lib function we can leverage to get this
+ * behavior which means we'd have to implement the full stack ourselves :(.
+ */
+
int readlink_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int readlink_main(int argc, char **argv)
+int readlink_main(int argc UNUSED_PARAM, char **argv)
{
char *buf;
char *fname;
- char pathbuf[PATH_MAX];
- USE_FEATURE_READLINK_FOLLOW(
+ IF_FEATURE_READLINK_FOLLOW(
unsigned opt;
/* We need exactly one non-option argument. */
- opt_complementary = "=1";
- opt = getopt32(argv, "f");
+ opt = getopt32(argv, "^" "fnvsq" "\0" "=1");
fname = argv[optind];
)
- SKIP_FEATURE_READLINK_FOLLOW(
+ 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 */
- logmode = LOGMODE_NONE;
+ if (!(opt & 4)) /* not -v */
+ logmode = LOGMODE_NONE;
- if (opt) {
- buf = realpath(fname, pathbuf);
+ /* NOFORK: only one alloc is allowed; must free */
+ if (opt & 1) { /* -f */
+ buf = xmalloc_realpath_coreutils(fname);
} else {
buf = xmalloc_readlink_or_warn(fname);
}
if (!buf)
return EXIT_FAILURE;
- puts(buf);
-
- if (ENABLE_FEATURE_CLEAN_UP && !opt)
- free(buf);
+ printf((opt & 2) ? "%s" : "%s\n", buf);
+ free(buf);
fflush_stdout_and_exit(EXIT_SUCCESS);
}