Tweaks to argument handling

mkd2html.c

@@ -81,7 +81,7 @@ char **argv;
     CREATE(footers);
     pgm = basename(argv[0]);
 
-    while ( argc > 2 ) {
+    while ( argc ) {
 	if ( strcmp(argv[1], "-css") == 0 ) {
 	    EXPAND(css) = argv[2];
 	    argc -= 2;
@@ -97,14 +97,20 @@ char **argv;
 	    argc -= 2;
 	    argv += 2;
 	}
+	else
+	    break;
     }
 
-
-    if ( argc > 1 ) {
+    switch ( argc ) {
 	char *p, *dot;
-	
+    case 1:
+	input = stdin;
+	output = stdout;
+	break;
+    case 2:
+    case 3:
+	dest   = malloc(strlen(argv[argc-1]) + 6);
 	source = malloc(strlen(argv[1]) + 6);
-	dest   = malloc(strlen(argv[1]) + 6);
 
 	if ( !(source && dest) )
 	    fail("out of memory allocating name buffers");
@@ -128,10 +134,11 @@ char **argv;
 
 	if ( (output = fopen(dest, "w")) == 0 )
 	    fail("can't write to %s", dest);
-    }
-    else {
-	input = stdin;
-	output = stdout;
+	break;
+
+    default:
+	fprintf(stderr, "usage: %s [opts] source [dest]\n", pgm);
+	exit(1);
     }
 
     if ( (mmiot = mkd_in(input, 0)) == 0 )