1 files changed, 52 insertions, 1 deletions

diff --git a/src/calculer.c b/src/calculer.c
index 062fff6..5eefb87 100644
--- a/src/calculer.c
+++ b/src/calculer.c
@@ -23,6 +23,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+#include <unistd.h>
 
 #include "linenoise.h"
 
@@ -69,8 +70,35 @@ measure_after(void *data, int correct)
 	return bytes_written != fwrite(logbuf, 1, bytes_written, logfile);
 }
 
+#define print_opt_noarg(opt, desc) \
+	fprintf(stream, "  -"opt"\t"desc"\n")
+
+
+void
+print_usage(FILE *stream)
+{
+	fprintf(stream, "Usage: calculer [OPTIONS]\n");
+	fprintf(stream, "OPTIONS\n");
+	print_opt_noarg("V", "Print version and exit.");
+	print_opt_noarg("h", "Print help and exit.");
+}
+
+void
+print_help(void)
+{
+	printf("calculer -- train mental calculus\n");
+	printf("calculer is licensed under the GPL3 License.\n");
+	print_usage(stdout);
+}
+
+void
+print_version(void)
+{
+	printf("%s\n", VERSION);
+}
+
 int
-main(void)
+main(int argc, char *argv[])
 {
 	srand(time(NULL));
 	logfile = fopen("./calculer.log", "a");
@@ -81,6 +109,29 @@ main(void)
 	size_t bytes_written = strftime(logbuf, sizeof(logbuf), "%F\t", tm);
 	assert(bytes_written);
 
+	int opt;
+	while ((opt = getopt(argc, argv, ":Vh")) != -1)
+	{
+		switch (opt)
+		{
+		case 'V':
+			print_version();
+			exit(0);
+		case 'h':
+			print_help();
+			exit(0);
+		case ':':
+			fprintf(stderr,
+				"calculer: option %d requires an argument\n",
+				optopt);
+			print_usage(stderr);
+			exit(1);
+		default:
+			print_usage(stderr);
+			exit(1);
+		}
+	}
+
 	while (1)
 	{
 		char prompt[32] = {0};