Use strtol instead of checking each digit

This makes it both faster and smaller.

2 files changed, 17 insertions, 18 deletions

diff --git a/main.c b/main.c
index c1a8b23..d986924 100644
--- a/main.c
+++ b/main.c
@@ -29,12 +29,13 @@ void printversion() {
 
 int main(int argc, char **argv) {
   bool quiet;
-  size_t string_length;
-  uint8_t digit;
+  bool value;
+  long result;
 
-  digit = 0;
   quiet = false;
-  string_length = 0;
+  value = false;
+  result = 0;
+  char *output;
 
   if (argc > 1) {
     for (size_t i = 1; i < argc; i++) {
@@ -52,26 +53,23 @@ int main(int argc, char **argv) {
           case 'q':
             quiet = true;
             break;
-          default:
-            printhelp();
-            return -1;
         }
       }
+      result = strtol(argv[i], &output, 10);
+      value = true;
     }
-    assert(strlen(argv[argc - 1]) < SIZE_MAX);
-    string_length = strlen(argv[argc - 1]);
-    digit = argv[argc - 1][string_length - 1];
-    digit -= '0';
-    if (quiet) {
-      if (digit <= 10)
-        return ((digit & 1) == 0) ? SUCCESS : ERR;
-    } else {
-      if ((digit & 1) == 0) {
+  }
+  if (value) {
+    if (result % 2 == 0) {
+      if (quiet) {
         fprintf(stdout, "even\n");
-      } else {
+      }
+      return 0;
+    } else {
+      if (quiet) {
         fprintf(stdout, "odd\n");
       }
-      return SUCCESS;
+      return 1;
     }
   }
   return ERR;
diff --git a/main.h b/main.h
index 61f7b1c..d6d758e 100644
--- a/main.h
+++ b/main.h
@@ -6,6 +6,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <stdlib.h>
 
 #include <assert.h>
 #include <string.h>