1124

1 files changed, 5 insertions, 1 deletions

diff --git a/cpp/001test b/cpp/001test
index 12352de1..8c4bc5e3 100644
--- a/cpp/001test
+++ b/cpp/001test
@@ -48,7 +48,7 @@ if (argc == 2 && is_equal(argv[1], "test")) {
   return 0;
 }
 // pass in a set of line numbers in test_file to run just those tests
-if (argc > 2 && is_equal(argv[1], "test")) {
+if (argc > 2 && is_equal(argv[1], "test") && is_number(argv[2])) {
   for (int i = 2; i < argc; ++i) {
     run_test(to_int(argv[i])-1);
   }
@@ -87,6 +87,10 @@ bool is_equal(char* s, const char* lit) {
   return strncmp(s, lit, strlen(lit)) == 0;
 }
 
+bool is_number(const string& s) {
+  return s.find_first_not_of("0123456789-.") == string::npos;
+}
+
 int to_int(string n) {
   char* end = NULL;
   int result = strtol(n.c_str(), &end, /*any base*/0);