Generate usage message from comments in the .rst.

1 files changed, 19 insertions, 5 deletions

diff --git a/src/unalf.c b/src/unalf.c
index 9a722f8..d4b5aa0 100644
--- a/src/unalf.c
+++ b/src/unalf.c
@@ -7,6 +7,10 @@
 #include <f65.h>
 #include "unalf.h"
 
+#ifndef VERSION
+#define VERSION "0.0.0"
+#endif
+
 FILE *in_file, *out_file;
 char *in_filename, *self;
 opts_t opts;
@@ -15,11 +19,6 @@ int exclude_count;
 char * const *include_globs;
 static void create_outdir(void);
 
-static void usage(void) {
-	printf("usage: %s [-l] file.alf\n", self);
-	exit(1);
-}
-
 static void set_self(char *argv0) {
 	char *p;
 
@@ -48,6 +47,21 @@ static void create_outdir(void) {
 	}
 }
 
+void usage(void) {
+	extern char *usage_msg[];
+	char **line;
+
+	puts("unalf (ALF extractor) v" VERSION " by B. Watson. WTFPL.");
+	printf("Usage: %s -[options] <file> [wildcard ...]\n", self);
+	puts("Options:");
+	puts("  wildcards: extract only matching files.");
+
+	for(line = usage_msg; *line; line++)
+		puts(*line);
+
+	exit(0);
+}
+
 int main(int argc, char **argv) {
 	set_self(argv[0]);