X-Git-Url: https://git.draconx.ca/gitweb/rarpd-dx.git/blobdiff_plain/7848d2e1002e486171bd4e6a1b8d84d64f389af4..e47d657a9839025639a93fbf4b3d57f24508f284:/src/rarpd.c

diff --git a/src/rarpd.c b/src/rarpd.c
index 76b92e5..b7aa2e1 100644
--- a/src/rarpd.c
+++ b/src/rarpd.c
@@ -48,8 +48,9 @@ int listen_arp;
 char *ifname;
 char *tftp_dir = "/etc/tftpboot";
 
+static const char *progname = "rarpd";
+
 extern int ether_ntohost(char *name, unsigned char *ea);
-void usage(void) __attribute__((noreturn));
 
 struct iflink
 {
@@ -80,22 +81,30 @@ struct rarp_map
 	uint32_t		ipaddr;
 } *rarp_db;
 
-void usage(void)
+static void print_usage(FILE *f)
 {
-	fprintf(stderr,
-		"\nUsage:\n"
-		"  rarpd [options] [interface]\n"
-		"\nOptions:\n"
-		"  -A        listen also arp messages\n"
-		"  -a        listen on all the interfaces\n"
-		"  -b <dir>  tftpd boot directory\n"
-		"  -d        debug mode\n"
-		"  -e        /etc/ethers markup alone is fine\n"
-		"  -v        verbose mode\n"
-		"  -V        print version and exit\n"
-		"\nFor more details see rarpd(8).\n"
-	);
-	exit(1);
+	fprintf(f, "Usage: %s [options] [interface]\n", progname);
+	if (f != stdout)
+		fprintf(f, "Try %s -H for more information.\n", progname);
+}
+
+static void print_help(void)
+{
+	print_usage(stdout);
+	putchar('\n');
+
+	puts("Options:");
+	puts("  -A        listen also arp messages");
+	puts("  -a        listen on all the interfaces");
+	puts("  -b <dir>  tftpd boot directory");
+	puts("  -d        debug mode");
+	puts("  -e        /etc/ethers markup alone is fine");
+	puts("  -v        verbose mode");
+	puts("  -V        print version and then exit");
+	puts("  -H        print this message and then exit");
+	putchar('\n');
+
+	puts("For more information, see the rarpd(8) man page.");
 }
 
 static void print_version(void)
@@ -588,8 +597,11 @@ int main(int argc, char **argv)
 	int psize;
 	int opt;
 
+	if (argc > 0)
+		progname = argv[0];
+
 	opterr = 0;
-	while ((opt = getopt(argc, argv, "aAb:dvoeV")) != EOF) {
+	while ((opt = getopt(argc, argv, "aAb:dvoeVH")) != EOF) {
 		switch (opt) {
 		case 'a':
 			++all_ifaces;
@@ -621,13 +633,19 @@ int main(int argc, char **argv)
 		case 'V':
 			print_version();
 			return 0;
+		case 'H':
+			print_help();
+			return 0;
 		default:
-			usage();
+			print_usage(stderr);
+			return EXIT_FAILURE;
 		}
 	}
 	if (argc > optind) {
-		if (argc > optind+1)
-			usage();
+		if (argc > optind+1) {
+			print_usage(stderr);
+			return EXIT_FAILURE;
+		}
 		ifname = argv[optind];
 	}