3 files changed, 20 insertions, 23 deletions

diff --git a/tools/mirb/mirb.c b/tools/mirb/mirb.c
index 3f96696a7..ed3b105b6 100644
--- a/tools/mirb/mirb.c
+++ b/tools/mirb/mirb.c
@@ -172,19 +172,17 @@ parse_args(mrb_state *mrb, int argc, char **argv, struct _args *args)
     case '-':
       if (strcmp((*argv) + 2, "version") == 0) {
         mrb_show_version(mrb);
-        exit(0);
+        exit(EXIT_SUCCESS);
       }
       else if (strcmp((*argv) + 2, "copyright") == 0) {
         mrb_show_copyright(mrb);
-        exit(0);
+        exit(EXIT_SUCCESS);
       }
-      else return -3;
     default:
-      return -4;
+      return EXIT_FAILURE;
     }
   }
-
-  return 0;
+  return EXIT_SUCCESS;
 }
 
 static void
@@ -240,7 +238,7 @@ main(int argc, char **argv)
   }
 
   n = parse_args(mrb, argc, argv, &args);
-  if (n < 0) {
+  if (n == EXIT_FAILURE) {
     cleanup(mrb, &args);
     usage(argv[0]);
     return n;
diff --git a/tools/mrbc/mrbc.c b/tools/mrbc/mrbc.c
index b8c1cf286..8698086ff 100644
--- a/tools/mrbc/mrbc.c
+++ b/tools/mrbc/mrbc.c
@@ -69,7 +69,7 @@ parse_args(mrb_state *mrb, int argc, char **argv, struct _args *args)
   char *infile = NULL;
   char *outfile = NULL;
   char **origargv = argv;
-  int result = 0;
+  int result = EXIT_SUCCESS;
   static const struct _args args_zero = { 0 };
 
   *args = args_zero;
@@ -88,7 +88,7 @@ parse_args(mrb_state *mrb, int argc, char **argv, struct _args *args)
         if (outfile) {
           printf("%s: An output file is already specified. (%s)\n",
                  *origargv, outfile);
-          result = -5;
+          result = EXIT_FAILURE;
           goto exit;
         }
         outfile = get_outfilename((*argv) + 2, "");
@@ -98,7 +98,7 @@ parse_args(mrb_state *mrb, int argc, char **argv, struct _args *args)
         args->initname = (*argv) + 2;
         if (*args->initname == '\0') {
           printf("%s: Function name is not specified.\n", *origargv);
-          result = -2;
+          result = EXIT_FAILURE;
           goto exit;
         }
         break;
@@ -115,7 +115,7 @@ parse_args(mrb_state *mrb, int argc, char **argv, struct _args *args)
       case '-':
         if (strcmp((*argv) + 2, "version") == 0) {
           mrb_show_version(mrb);
-          exit(0);
+          exit(EXIT_SUCCESS);
         }
         else if (strcmp((*argv) + 2, "verbose") == 0) {
           args->verbose = 1;
@@ -123,9 +123,9 @@ parse_args(mrb_state *mrb, int argc, char **argv, struct _args *args)
         }
         else if (strcmp((*argv) + 2, "copyright") == 0) {
           mrb_show_copyright(mrb);
-          exit(0);
+          exit(EXIT_SUCCESS);
         }
-        result = -3;
+        result = EXIT_FAILURE;
         goto exit;
       default:
         break;
@@ -141,7 +141,7 @@ parse_args(mrb_state *mrb, int argc, char **argv, struct _args *args)
   }
 
   if (infile == NULL) {
-    result = -4;
+    result = EXIT_FAILURE;
     goto exit;
   }
   if (!args->check_syntax) {
@@ -158,7 +158,7 @@ parse_args(mrb_state *mrb, int argc, char **argv, struct _args *args)
     }
     else if ((args->wfp = fopen(outfile, "wb")) == NULL) {
       printf("%s: Cannot open output file. (%s)\n", *origargv, outfile);
-      result = -1;
+      result = EXIT_FAILURE;
       goto exit;
     }
   }
@@ -192,7 +192,7 @@ main(int argc, char **argv)
   }
 
   n = parse_args(mrb, argc, argv, &args);
-  if (n < 0 || args.rfp == NULL) {
+  if (n == EXIT_FAILURE || args.rfp == NULL) {
     cleanup(mrb, &args);
     usage(argv[0]);
     return n;
diff --git a/tools/mruby/mruby.c b/tools/mruby/mruby.c
index 47727e67b..c52eb5e7b 100644
--- a/tools/mruby/mruby.c
+++ b/tools/mruby/mruby.c
@@ -105,7 +105,7 @@ append_cmdline:
       }
       else {
         printf("%s: No code specified for -e\n", *origargv);
-        return 0;
+        return EXIT_SUCCESS;
       }
       break;
     case 'v':
@@ -115,7 +115,7 @@ append_cmdline:
     case '-':
       if (strcmp((*argv) + 2, "version") == 0) {
         mrb_show_version(mrb);
-        exit(0);
+        exit(EXIT_SUCCESS);
       }
       else if (strcmp((*argv) + 2, "verbose") == 0) {
         args->verbose = 1;
@@ -123,11 +123,10 @@ append_cmdline:
       }
       else if (strcmp((*argv) + 2, "copyright") == 0) {
         mrb_show_copyright(mrb);
-        exit(0);
+        exit(EXIT_SUCCESS);
       }
-      else return -3;
     default:
-      return -4;
+      return EXIT_FAILURE;
     }
   }
 
@@ -148,7 +147,7 @@ append_cmdline:
   memcpy(args->argv, argv, (argc+1) * sizeof(char*));
   args->argc = argc;
 
-  return 0;
+  return EXIT_SUCCESS;
 }
 
 static void
@@ -240,7 +239,7 @@ main(int argc, char **argv)
   }
 
   n = parse_args(mrb, argc, argv, &args);
-  if (n < 0 || (args.cmdline == NULL && args.rfp == NULL)) {
+  if (n == EXIT_FAILURE || (args.cmdline == NULL && args.rfp == NULL)) {
     cleanup(mrb, &args);
     usage(argv[0]);
     return n;