Make -help & -version work without requiring an open display

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>

3 files changed, 26 insertions, 14 deletions

diff --git a/dsimple.c b/dsimple.c
index 8882822..2546072 100644
--- a/dsimple.c
+++ b/dsimple.c
@@ -77,7 +77,7 @@ Get_Display_Name(int *pargc,    /* MODIFIED */
 
         if (!strcmp(arg, "-display") || !strcmp(arg, "-d")) {
             if (++i >= argc)
-                usage("-display requires an argument");
+                usage("-display requires an argument", EXIT_FAILURE);
 
             displayname = argv[i];
             *pargc -= 2;
@@ -184,7 +184,8 @@ Select_Window_Args(int *rargc, char **argv)
 
 #define OPTION argv[0]
 #define NXTOPTP ++argv, --argc>0
-#define NXTOPT(arg) if (++argv, --argc==0) usage(arg " requires an argument")
+#define NXTOPT(arg) if (++argv, --argc==0) \
+        usage(arg " requires an argument", EXIT_FAILURE)
 #define COPYOPT nargv++[0]=OPTION, nargc++
 
     while (NXTOPTP) {
diff --git a/dsimple.h b/dsimple.h
index 416e96a..1a24313 100644
--- a/dsimple.h
+++ b/dsimple.h
@@ -61,7 +61,7 @@ Display *Open_Display(const char *);
 void Setup_Display_And_Screen(int *, char **);
 void Close_Display(void);
 Window Select_Window_Args(int *, char **);
-void usage(const char *errmsg) _X_NORETURN _X_COLD;
+void usage(const char *errmsg, int exitval) _X_NORETURN _X_COLD;
 
 #define X_USAGE "[host:display]"             /* X arguments handled by
                                                 Get_Display_Name */
diff --git a/xwd.c b/xwd.c
index 0ea4168..98ac506 100644
--- a/xwd.c
+++ b/xwd.c
@@ -148,6 +148,23 @@ main(int argc, char **argv)
 
     INIT_NAME;
 
+    /* Handle args that don't require opening a display */
+    for (int n = 1; n < argc; n++) {
+	const char *argn = argv[n];
+	/* accept single or double dash for -help & -version */
+	if (argn[0] == '-' && argn[1] == '-') {
+	    argn++;
+	}
+	if (strcmp (argn, "-help") == 0) {
+	    usage(NULL, EXIT_SUCCESS);
+	    exit(0);
+	}
+	if (strcmp (argn, "-version") == 0) {
+	    puts(PACKAGE_STRING);
+	    exit(EXIT_SUCCESS);
+	}
+    }
+
     Setup_Display_And_Screen(&argc, argv);
 
     /* Get window select on command line, if any */
@@ -162,11 +179,9 @@ main(int argc, char **argv)
             debug = True;
             continue;
         }
-        if (!strcmp(argv[i], "-help"))
-            usage(NULL);
         if (!strcmp(argv[i], "-out")) {
             if (++i >= argc)
-                usage("-out requires an argument");
+                usage("-out requires an argument", EXIT_FAILURE);
             if (!(out_file = fopen(argv[i], "wb")))
                 Fatal_Error("Can't open output file as specified.");
             standard_out = False;
@@ -186,7 +201,7 @@ main(int argc, char **argv)
         }
         if (!strcmp(argv[i], "-add")) {
             if (++i >= argc)
-                usage("-add requires an argument");
+                usage("-add requires an argument", EXIT_FAILURE);
             add_pixel_value = parse_long(argv[i]);
             continue;
         }
@@ -198,13 +213,9 @@ main(int argc, char **argv)
             silent = True;
             continue;
         }
-        if (!strcmp(argv[i], "-version")) {
-            puts(PACKAGE_STRING);
-            exit(0);
-        }
         fprintf(stderr, "%s: unrecognized argument '%s'\n",
                 program_name, argv[i]);
-        usage(NULL);
+        usage(NULL, EXIT_FAILURE);
     }
 #ifdef WIN32
     if (standard_out)
@@ -546,7 +557,7 @@ Window_Dump(Window window, FILE *out)
  * Report the syntax for calling xwd.
  */
 void
-usage(const char *errmsg)
+usage(const char *errmsg, int exitval)
 {
     if (errmsg != NULL)
         fprintf(stderr, "%s: %s\n", program_name, errmsg);
@@ -572,7 +583,7 @@ usage(const char *errmsg)
           "  -icmap                   Use the first colormap of the screen\n"
           "  -screen                  Send the request against the root window\n"
           "  -silent                  Don't ring any bells\n", stderr);
-    exit(1);
+    exit(exitval);
 }
 
 /*