[PATCH v1] erofs-utils: introduce long parameter option

[Li Guifu]

From: Li Guifu <blucerlee at gmail.com>

Only --help|-h is uesed right now

Signed-off-by: Li Guifu <blucerlee at gmail.com>
---
 mkfs/main.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/mkfs/main.c b/mkfs/main.c
index 71c81f5..f62b065 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -13,6 +13,8 @@
 #include <limits.h>
 #include <libgen.h>
 #include <sys/stat.h>
+#include <getopt.h>
+
 #include "erofs/config.h"
 #include "erofs/print.h"
 #include "erofs/cache.h"
@@ -23,10 +25,16 @@
 
 #define EROFS_SUPER_END (EROFS_SUPER_OFFSET + sizeof(struct erofs_super_block))
 
+static struct option long_options[] = {
+	{"help", no_argument, 0, 'h'},
+	{0, 0, 0, 0},
+};
+
 static void usage(void)
 {
 	fprintf(stderr, "usage: [options] FILE DIRECTORY\n\n");
 	fprintf(stderr, "Generate erofs image from DIRECTORY to FILE, and [options] are:\n");
+	fprintf(stderr, " -h|--help print usage message then exit 0\n");
 	fprintf(stderr, " -zX[,Y]   X=compressor (Y=compression level, optional)\n");
 	fprintf(stderr, " -d#       set output message level to # (maximum 9)\n");
 	fprintf(stderr, " -x#       set xattr tolerance to # (< 0, disable xattrs; default 2)\n");
@@ -95,8 +103,10 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
 {
 	char *endptr;
 	int opt, i;
+	int option_index = 0;
 
-	while ((opt = getopt(argc, argv, "d:x:z:E:T:")) != -1) {
+	while((opt = getopt_long(argc, argv, "d:z:E:T:h", long_options,
+				 &option_index)) != -1) {
 		switch (opt) {
 		case 'z':
 			if (!optarg) {
@@ -146,6 +156,11 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
 			}
 			break;
 
+		case 'h':
+		case '?':
+			usage();
+			exit(0);
+
 		default: /* '?' */
 			return -EINVAL;
 		}
-- 
2.17.1