Add support for long options to cmp

In order to improve compatibility with GNU cmp add support for long
options to busybox cmp.

function                                             old     new   delta
static.cmp_longopts                                    -      36     +36
cmp_main                                             589     594      +5
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 1/0 up/down: 41/0)               Total: 41 bytes

Signed-off-by: Walter Lozano <walter.lozano@collabora.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/editors/cmp.c b/editors/cmp.c
index 6d2b0c6c3..b89e519ad 100644
--- a/editors/cmp.c
+++ b/editors/cmp.c
@@ -54,6 +54,7 @@ int cmp_main(int argc UNUSED_PARAM, char **argv)
         int retval = 0;
         int max_count = -1;
 
+#if !ENABLE_LONG_OPTS
         opt = getopt32(argv, "^"
                         OPT_STR
                         "\0" "-1"
@@ -62,6 +63,23 @@ int cmp_main(int argc UNUSED_PARAM, char **argv)
                         ":l--s:s--l",
                         &max_count
         );
+#else
+        static const char cmp_longopts[] ALIGN1 =
+                "bytes\0"          Required_argument  "n"
+                "quiet\0"          No_argument        "s"
+                "silent\0"         No_argument        "s"
+                "verbose\0"        No_argument        "l"
+                ;
+        opt = getopt32long(argv, "^"
+                        OPT_STR
+                        "\0" "-1"
+                        IF_DESKTOP(":?4")
+                        IF_NOT_DESKTOP(":?2")
+                        ":l--s:s--l",
+                        cmp_longopts,
+                        &max_count
+        );
+#endif
         argv += optind;
 
         filename1 = *argv;