readlink: support -n, -v, -s and -q too if support for -f is requested

function                                             old     new   delta
readlink_main                                        104     135     +31
packed_usage                                       26322   26321      -1
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 31/-1)              Total: 30 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 28 insertions, 5 deletions

diff --git a/coreutils/readlink.c b/coreutils/readlink.c
index 8d4456214..20df38b96 100644
--- a/coreutils/readlink.c
+++ b/coreutils/readlink.c
@@ -6,9 +6,31 @@
  *
  * 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)
 {
@@ -20,7 +42,7 @@ int readlink_main(int argc UNUSED_PARAM, char **argv)
 		unsigned opt;
 		/* We need exactly one non-option argument.  */
 		opt_complementary = "=1";
-		opt = getopt32(argv, "f");
+		opt = getopt32(argv, "fnvsq");
 		fname = argv[optind];
 	)
 	IF_NOT_FEATURE_READLINK_FOLLOW(
@@ -30,9 +52,10 @@ int readlink_main(int argc UNUSED_PARAM, char **argv)
 	)
 
 	/* compat: coreutils readlink reports errors silently via exit code */
-	logmode = LOGMODE_NONE;
+	if (!(opt & 4)) /* not -v */
+		logmode = LOGMODE_NONE;
 
-	if (opt) {
+	if (opt & 1) { /* -f */
 		buf = realpath(fname, pathbuf);
 	} else {
 		buf = xmalloc_readlink_or_warn(fname);
@@ -40,7 +63,7 @@ int readlink_main(int argc UNUSED_PARAM, char **argv)
 
 	if (!buf)
 		return EXIT_FAILURE;
-	puts(buf);
+	printf((opt & 2) ? "%s" : "%s\n", buf);
 
 	if (ENABLE_FEATURE_CLEAN_UP && !opt)
 		free(buf);