hush: if we did match "LINENO" or "OPTIND", stop further comparisons

[oweals/busybox.git] / coreutils / readlink.c

diff --git a/coreutils/readlink.c b/coreutils/readlink.c
index d454cbf19d3df45d86ab124dd09c2861c665c4a7..b8e327d11863fcd5025b0dc26d06f91d9cedae32 100644 (file)
--- a/coreutils/readlink.c
+++ b/coreutils/readlink.c
@@ -4,47 +4,97 @@
  *
  * 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).
 
-#include <getopt.h>
+//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 "libbb.h"
 
-int readlink_main(int argc, char **argv);
-int readlink_main(int argc, char **argv)
+/*
+ * # 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 UNUSED_PARAM, char **argv)
 {
        char *buf;
        char *fname;
 
-       USE_FEATURE_READLINK_FOLLOW(
+       IF_FEATURE_READLINK_FOLLOW(
                unsigned opt;
                /* We need exactly one non-option argument.  */
-               opt_complementary = "=1";
-               opt = getopt32(argc, 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, bb_common_bufsiz1);
+       /* NOFORK: only one alloc is allowed; must free */
+       if (opt & 1) { /* -f */
+               buf = xmalloc_realpath(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);
 }