.

src/nice.c

@@ -80,13 +80,35 @@ main (argc, argv)
 
   program_name = argv[0];
 
+  /* Inhibit the error message getopt would otherwise give for
+     unrecognized options.  */
+  opterr = 0;
+
   while ((optc = getopt_long (argc, argv, "+0123456789-n:", longopts,
 			      (int *) 0)) != EOF)
     {
+      char *s;
+
       switch (optc)
 	{
 	case '?':
-	  usage (1);
+	  /* Determine whether this is an option like `--5'.
+	     If so, treat it like `-n -5'.  */
+	  s = argv[optind - 1];
+	  /* Make sure s[1..] is a valid negative integer.
+	     Test/convert `s+1' rather than `s+2' so we reject options
+	     like `---5' as unrecognized.  */
+	  if (s[1] == '-' && isinteger (s + 1))
+	    {
+	      adjustment = atoi (s + 1);
+	      adjustment_given = 1;
+	    }
+	  else
+	    {
+	      error (0, 0, "unrecognized option `%s'", s);
+	      usage (1);
+	    }
+	  break;
 
 	case 0:
 	  break;