Use strerror_r to make error messages more useful

This commit adds a new file, common.h, which contains private macros
and static functions to make the code cleaner.

1 files changed, 18 insertions, 3 deletions

diff --git a/src/main.c b/src/main.c
index fde8aef..2370f5a 100644
--- a/src/main.c
+++ b/src/main.c
@@ -3,25 +3,40 @@
 #endif
 
 #include "ast.h"
+#include "common.h"
 #include "libparser_a-parser.h"
 
+#include <errno.h>
+#include <locale.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+
 
 extern FILE *yyin;
 extern AST_NODE *prog;
 
+const char *ccmmc_main_name;
+
 int main (int argc, char **argv)
 {
+    ERR_DECL;
+    setlocale (LC_ALL, "");
+    name = strrchr (argv[0], '/');
+    name = name == NULL ? name : name + 1;
+
     if (argc != 2) {
-        fputs("usage: parser [source file]\n", stderr);
+        fprintf(stderr, "Usage: %s SOURCE\n", name);
         exit(1);
     }
-    yyin = fopen(argv[1],"r");
+
+    const char *filename = argv[1];
+    yyin = fopen(filename, "r");
     if (yyin == NULL) {
-        fputs("Error opening source file.\n", stderr);
+        fprintf(stderr, "%s: %s: %s\n", name, filename, ERR_MSG);
         exit(1);
     }
+
     yyparse();
     printGV(prog, NULL);
     return 0;