[PATCH evemu 2/3] tools: play: use getopt

[Benjamin Tissoires]

Instead of relying on argc and hard coded values, use getopt framework.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires at gmail.com>
---
 tools/evemu-play.c | 37 +++++++++++++++++++++++++++++++++----
 1 file changed, 33 insertions(+), 4 deletions(-)

diff --git a/tools/evemu-play.c b/tools/evemu-play.c
index 8d14618..030e142 100644
--- a/tools/evemu-play.c
+++ b/tools/evemu-play.c
@@ -45,10 +45,18 @@
 #include <fcntl.h>
 #include <string.h>
 #include <unistd.h>
+#include <getopt.h>
+
+static struct option opts[] = {
+	{ "help", no_argument, 0, 'h'},
+};
 
 static void usage(void)
 {
-	fprintf(stderr, "Usage: %s <device>\n", program_invocation_short_name);
+	fprintf(stderr, "Usage: %s [OPTION] <device>\n", program_invocation_short_name);
+	fprintf(stderr, "\n");
+	fprintf(stderr, "Where OPTION is:\n");
+	fprintf(stderr, "   -h or --help: print this message\n");
 	fprintf(stderr, "\n");
 	fprintf(stderr, "Event data is read from standard input.\n");
 }
@@ -56,11 +64,30 @@ static void usage(void)
 int main(int argc, char *argv[])
 {
 	int fd;
-	if (argc != 2) {
+
+	while(1) {
+		int option_index = 0;
+		int c;
+
+		c = getopt_long(argc, argv, "h", opts, &option_index);
+		if (c == -1) /* Detect the end of the options. */
+			break;
+
+		switch(c) {
+			case 'h': /* help */
+			default:
+				usage();
+				goto out;
+		}
+	}
+
+	/* if the device was not specified, fail */
+	if (optind >= argc) {
 		usage();
-		return -1;
+		goto out;
 	}
-	fd = open(argv[1], O_WRONLY);
+
+	fd = open(argv[optind], O_WRONLY);
 	if (fd < 0) {
 		fprintf(stderr, "error: could not open device\n");
 		return -1;
@@ -70,4 +97,6 @@ int main(int argc, char *argv[])
 	}
 	close(fd);
 	return 0;
+out:
+	return -1;
 }
-- 
1.8.3.1