Add -help and -version options

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

1 files changed, 30 insertions, 2 deletions

diff --git a/xmore.c b/xmore.c
index 4ff53f4..f2f00c4 100644
--- a/xmore.c
+++ b/xmore.c
@@ -25,6 +25,10 @@ in this Software without prior written authorization from The Open Group.
  *
  */
 
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
 /* Force ANSI C prototypes from X11 headers */
 #ifndef FUNCPROTO 
 #define FUNCPROTO 15
@@ -128,6 +132,15 @@ quitXtProc(Widget w, XtPointer client_data, XtPointer callData)
     XtCallActionProc(w, "quit", NULL, NULL, 0);
 }
 
+static void
+usage(FILE *out, int exitval)
+{
+  fprintf(out,
+          "usage: %s [ x options ] [-help|-version] filename\n",
+          ProgramName);
+  exit(exitval);
+}
+
 int main( int argc, char *argv[] )
 {
   XtAppContext app;
@@ -138,6 +151,22 @@ int main( int argc, char *argv[] )
 
   ProgramName = argv[0];
 
+  /* Handle args that don't require opening a display */
+  for (int i = 1; i < argc; i++) {
+    const char *argn = argv[i];
+    /* accept single or double dash for -help & -version */
+    if (argn[0] == '-' && argn[1] == '-') {
+      argn++;
+    }
+    if (strcmp (argn, "-help") == 0) {
+      usage(stdout, EXIT_SUCCESS);
+    }
+    if (strcmp (argn, "-version") == 0) {
+      puts(PACKAGE_STRING);
+      exit(EXIT_SUCCESS);
+    }
+  }
+
   XtSetLanguageProc(NULL, NULL, NULL);
   toplevel = XtOpenApplication(&app, "XMore",
                                options, XtNumber(options), 
@@ -151,8 +180,7 @@ int main( int argc, char *argv[] )
       fprintf(stderr, " %s", argv[i]);
     }
     fputs("\n\n", stderr);
-    printf("usage: %s [ x options ] filename\n", argv[0]);
-    exit(EXIT_FAILURE);
+    usage(stderr, EXIT_FAILURE);
   }
 
   XtGetApplicationResources(toplevel, (XtPointer)&userOptions, resources,