1 files changed, 26 insertions, 4 deletions

diff --git a/src/twm.c b/src/twm.c
index a981ac4..ce67806 100644
--- a/src/twm.c
+++ b/src/twm.c
@@ -229,6 +229,20 @@ usage(void)
     exit(EXIT_FAILURE);
 }
 
+static Bool
+brief_opt(const char *param, const char *option)
+{
+    size_t have = strlen(++param);
+    size_t want = strlen(option);
+    Bool result = False;
+
+    if (have <= want) {
+        if (!strncmp(param, option, have))
+            result = True;
+    }
+    return result;
+}
+
 /***********************************************************************
  *
  *  Procedure:
@@ -263,45 +277,53 @@ main(int argc, char *argv[])
                 printf("%s %s\n", ProgramName, Version);
                 exit(EXIT_SUCCESS);
             case 'd':          /* -display dpy */
-                if (strcmp(&argv[i][1], "display"))
+                if (!brief_opt(argv[i], "display"))
                     usage();
                 if (++i >= argc)
                     usage();
                 display_name = argv[i];
                 continue;
             case 's':          /* -single */
+                if (!brief_opt(argv[i], "single"))
+                    usage();
                 MultiScreen = FALSE;
                 continue;
 #ifdef XPRINT
             case 'n':          /* -noprint */
-                if (strcmp(&argv[i][1], "noprint"))
+                if (!brief_opt(argv[i], "noprint"))
                     usage();
                 NoPrintscreens = True;
                 continue;
 #endif                          /* XPRINT */
             case 'f':          /* -file twmrcfilename */
+                if (!brief_opt(argv[i], "file"))
+                    usage();
                 if (++i >= argc)
                     usage();
                 InitFile = argv[i];
                 continue;
             case 'v':          /* -verbose */
+                if (!brief_opt(argv[i], "verbose"))
+                    usage();
                 PrintErrorMessages = True;
                 continue;
             case 'c':          /* -clientId */
-                if (strcmp(&argv[i][1], "clientId"))
+                if (!brief_opt(argv[i], "clientId"))
                     usage();
                 if (++i >= argc)
                     usage();
                 client_id = argv[i];
                 continue;
             case 'r':          /* -restore */
-                if (strcmp(&argv[i][1], "restore"))
+                if (!brief_opt(argv[i], "restore"))
                     usage();
                 if (++i >= argc)
                     usage();
                 restore_filename = argv[i];
                 continue;
             case 'q':          /* -quiet */
+                if (!brief_opt(argv[i], "quiet"))
+                    usage();
                 PrintErrorMessages = False;
                 continue;
             }