require at least 1 digit for parse_number()

1 files changed, 11 insertions, 4 deletions

diff --git a/uxd.c b/uxd.c
index 0347917..e675348 100644
--- a/uxd.c
+++ b/uxd.c
@@ -199,16 +199,24 @@ void parse_colors(char *arg) {
 	bad_color = arg[3] - '0';
 }
 
+void number_err(int opt) {
+	fprintf(stderr, "%s: invalid number for -%c option.\n", self, opt);
+	exit(1);
+}
+
 long parse_number(int opt, const char *s) {
 	char *e;
 	long result;
 
 	result = strtol(s, &e, 0);
 
+	/* require at least one digit (otherwise -sk would be allowed) */
+	if(e == s)
+		number_err(opt);
+
 	/* buglets here: 100x is correctly rejected, but 100kx is allowed
 	   (the x is ignored). not gonna worry about it. some people might
-	   even make use of it: 100kb or 100Kb will work. also, a suffix
-	   by itself, like -sk, is accepted (and treated as zero). */
+	   even make use of it: 100kb or 100Kb will work. */
 	switch(*e) {
 		case 0: break;
 		case 'k': result *= 1024L; break;
@@ -218,8 +226,7 @@ long parse_number(int opt, const char *s) {
 		case 'M': result *= 1000000L; break;
 		case 'G': result *= 1000000000L; break;
 		default:
-			fprintf(stderr, "%s: invalid number for -%c option.\n", self, opt);
-			exit(1);
+			number_err(opt);
 	}
 
 	return result;