Add -help option

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

1 files changed, 12 insertions, 7 deletions

diff --git a/xrefresh.c b/xrefresh.c
index 768f8eb..6352747 100644
--- a/xrefresh.c
+++ b/xrefresh.c
@@ -70,9 +70,11 @@ static Window win;
 static char *ProgramName;
 
 static void _X_NORETURN _X_COLD
-Syntax(void)
+Syntax(int exitval)
 {
-    fprintf (stderr, "usage:  %s [-options] [geometry] [display]\n\n%s",
+    FILE *out = (exitval == EXIT_SUCCESS) ? stdout : stderr;
+
+    fprintf (out, "usage:  %s [-options] [geometry] [display]\n\n%s",
 	     ProgramName,
 	     "where the available options are:\n"
 	     "    -display host:dpy       or -d\n"
@@ -85,22 +87,22 @@ Syntax(void)
 	     "    -delay ms               time to hold refresh\n"
 	     "    -version                print program version\n"
 	);
-    fprintf(stderr, "\nThe default is:  %s -none -delay 0\n\n", ProgramName);
-    exit (1);
+    fprintf(out, "\nThe default is:  %s -none -delay 0\n\n", ProgramName);
+    exit (exitval);
 }
 
 static void _X_NORETURN _X_COLD
 missing_arg(const char *arg)
 {
     fprintf (stderr, "%s: %s requires an argument\n\n", ProgramName, arg);
-    Syntax ();
+    Syntax (EXIT_FAILURE);
 }
 
 static void _X_NORETURN _X_COLD
 unknown_arg(const char *arg)
 {
     fprintf (stderr, "%s: unrecognized argument %s\n\n", ProgramName, arg);
-    Syntax ();
+    Syntax (EXIT_FAILURE);
 }
 
 /*
@@ -238,7 +240,10 @@ main(int argc, char *argv[])
 	    }
 	    else if (isabbreviation ("-version", arg, 1)) {
 		puts(PACKAGE_STRING);
-		exit(0);
+		exit(EXIT_SUCCESS);
+            }
+	    else if (isabbreviation ("-help", arg, 1)) {
+		Syntax(EXIT_SUCCESS);
 	    } else 
 		unknown_arg (arg);
 	} else if (arg[0] == '=')			/* obsolete */