handle our own flag errors

source/error.c

@@ -32,6 +32,7 @@ void errorn(int i, ...) {
         case E_FILE_DELETE: verror("failed to delete file '%s'", argv);        break;
         case E_FILE_MOVE:   verror("failed to move '%s' to '%s'", argv);       break;
         case E_FORMAT:      verror("directive-file format violation", argv);   break;
+        case E_FLAG:        verror("unknown flag '%c'", argv);                 break;
         default: verror("unknown error encountered; this is an illegal inner state", 0); break;
     }
 

source/error.h

@@ -7,6 +7,7 @@ enum {
     E_FILE_DELETE,
     E_FILE_MOVE,
     E_FORMAT,
+    E_FLAG,
 };
 
 extern void errorn(int i, ...);

source/opts.c

@@ -5,9 +5,11 @@
 #include <string.h>
 #include <getopt.h>
 #include "global.h"
+#include "error.h"
 #include "dictate.h"
 
-void usage() {
+static
+void usage(void) {
     dictate(
         "$B$gvimdir$0 $y[$boptions$y] <$bpath$y>$0\n"
         "  $B$g-h$0 : print help\n"
@@ -44,6 +46,9 @@ void get_env(void) {
 
 void parse_args(int argc, char * * argv) {
     int opt;
+
+    opterr = 0; // suppress default getopt error messages
+
     while ((opt = getopt(argc, argv, "hnpor")) != -1) {
         switch (opt) {
             case 'h': {
@@ -62,11 +67,11 @@ void parse_args(int argc, char * * argv) {
             case 'r': {
                 is_recursive = true;
             } break;
-            default: {
-                fprintf(stderr, "Unknown option: -%c\n", optopt);
+            case '?': {
+                errorn(E_FLAG, optopt);
                 usage();
                 exit(1);
-            } break;
+            }
         }
     }