omldummy: introduce using getopt_long

Prepare for adding the --features cmdline arg following in a subsequent
patch.

Related: SYS#4895
Change-Id: I72ccf65ba894e87ee7b0f6bed879f94728f34ccc

1 files changed, 68 insertions, 12 deletions

diff --git a/src/osmo-bts-omldummy/main.c b/src/osmo-bts-omldummy/main.c
index 22d8758d..183a5e5b 100644
--- a/src/osmo-bts-omldummy/main.c
+++ b/src/osmo-bts-omldummy/main.c
@@ -1,3 +1,9 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#define _GNU_SOURCE
+#include <getopt.h>
 
 #include <osmocom/core/talloc.h>
 #include <osmocom/core/application.h>
@@ -6,6 +12,64 @@
 #include <osmo-bts/bts.h>
 #include <osmo-bts/oml.h>
 
+static void print_usage(const char *prog_name)
+{
+	printf("Usage: %s [-h] dst_host site_id [trx_num]\n", prog_name);
+}
+
+static void print_help(const char *prog_name)
+{
+	print_usage(prog_name);
+	printf("  -h --help			This text.\n");
+}
+
+struct {
+	char *dst_host;
+	int site_id;
+	int trx_num;
+} cmdline = {
+	.trx_num = 8,
+};
+
+void parse_cmdline(int argc, char **argv)
+{
+	while (1) {
+		int option_index = 0, c;
+		static struct option long_options[] = {
+			{"help", 0, 0, 'h'},
+			{0}
+		};
+
+		c = getopt_long(argc, argv, "h", long_options, &option_index);
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'h':
+			print_help(argv[0]);
+			exit(0);
+		default:
+			/* catch unknown options *as well as* missing arguments. */
+			fprintf(stderr, "Error in command line options. Exiting.\n");
+			exit(-1);
+		}
+	}
+
+	if (optind + 2 > argc) {
+		print_usage(argv[0]);
+		exit(1);
+	}
+
+	cmdline.dst_host = argv[optind];
+	cmdline.site_id = atoi(argv[optind + 1]);
+	if (optind + 2 < argc)
+		cmdline.trx_num = atoi(argv[optind + 2]);
+
+	if (optind + 3 < argc) {
+		print_usage(argv[0]);
+		exit(1);
+	}
+}
 
 int main(int argc, char **argv)
 {
@@ -14,14 +78,7 @@ int main(int argc, char **argv)
 	struct e1inp_line *line;
 	int i;
 
-	if (argc < 3) {
-		fprintf(stderr, "Usage: %s dst_host site_id [trx_num]\n", argv[0]);
-		return 1;
-	}
-
-	char *dst_host = argv[1];
-	int site_id = atoi(argv[2]);
-	int trx_num = argc > 3 ? atoi(argv[3]) : 8;
+	parse_cmdline(argc, argv);
 
 	tall_bts_ctx = talloc_named_const(NULL, 1, "OsmoBTS context");
 	msgb_talloc_ctx_init(tall_bts_ctx, 10*1024);
@@ -31,11 +88,11 @@ int main(int argc, char **argv)
 	bts = gsm_bts_alloc(tall_bts_ctx, 0);
 	if (!bts)
 		exit(1);
-	bts->ip_access.site_id = site_id;
+	bts->ip_access.site_id = cmdline.site_id;
 	bts->ip_access.bts_id = 0;
 
 	/* Additional TRXs */
-	for (i = 1; i < trx_num; i++) {
+	for (i = 1; i < cmdline.trx_num; i++) {
 		trx = gsm_bts_trx_alloc(bts);
 		if (!trx)
 			exit(1);
@@ -46,8 +103,7 @@ int main(int argc, char **argv)
 	//btsb = bts_role_bts(bts);
 	abis_init(bts);
 
-
-	line = abis_open(bts, dst_host, "OMLdummy");
+	line = abis_open(bts, cmdline.dst_host, "OMLdummy");
 	if (!line)
 		exit(2);