Add -help option

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

2 files changed, 26 insertions, 11 deletions

diff --git a/fslsfonts.c b/fslsfonts.c
index ce8f7ab..e31cd96 100644
--- a/fslsfonts.c
+++ b/fslsfonts.c
@@ -92,7 +92,7 @@ static FSServer *svr;
 
 static char *program_name;
 
-static void usage (const char *msg) _X_NORETURN _X_COLD;
+static void usage (const char *msg, int exitval) _X_NORETURN _X_COLD;
 static void get_list ( const char *pattern );
 static int compare ( const void *f1, const void *f2 );
 static void show_fonts ( void );
@@ -108,11 +108,11 @@ missing_arg (const char *option)
     char msg[32];
 
     snprintf(msg, sizeof(msg), "%s requires an argument", option);
-    usage(msg);
+    usage(msg, 1);
 }
 
 static void
-usage(const char *msg)
+usage(const char *msg, int exitval)
 {
     if (msg)
 	fprintf(stderr, "%s: %s\n", program_name, msg);
@@ -126,9 +126,10 @@ usage(const char *msg)
 	    "    -w width                 maximum width for multiple columns\n"
 	    "    -n columns               number of columns if multi column\n"
 	    "    -server servername       font server to contact\n"
+	    "    -help                    print this message and exit\n"
 	    "    -version                 print command version and exit\n"
 	    "\n");
-    exit(1);
+    exit(exitval);
 }
 
 int
@@ -146,15 +147,26 @@ main(int argc, char *argv[])
 		missing_arg("-server");
 	    servername = argv[i];
 	}
-	else if (strcmp(argv[i], "-version") == 0) {
-	    printf("%s\n", PACKAGE_STRING);
-	    exit(0);
+	else {
+	    const char *arg = argv[i];
+	    /* accept single or double dash for -help & -version */
+	    if (arg[0] == '-' && arg[1] == '-') {
+		arg++;
+	    }
+
+	    if (strcmp(arg, "-help") == 0) {
+		usage(NULL, 0);
+	    }
+	    else if (strcmp(arg, "-version") == 0) {
+		printf("%s\n", PACKAGE_STRING);
+		exit(0);
+	    }
 	}
     }
 
     if ((svr = FSOpenServer(servername)) == NULL) {
 	if (FSServerName(servername) == NULL) {
-	    usage("no font server defined");
+	    usage("no font server defined", 1);
 	}
 	fprintf(stderr, "%s:  unable to open server \"%s\"\n",
 		program_name, FSServerName(servername));
@@ -164,7 +176,7 @@ main(int argc, char *argv[])
     for (argv++, argc--; argc; argv++, argc--) {
 	if (argv[0][0] == '-') {
 	    if (argcnt > 0)
-		usage(NULL);
+		usage(NULL, 1);
 	    for (i = 1; argv[0][i]; i++)
 		switch (argv[0][i]) {
 		case 'l':
@@ -209,10 +221,10 @@ main(int argc, char *argv[])
 		default:
 		    fprintf(stderr, "%s: unrecognized option '%s'\n",
 			    program_name, argv[0]);
-		    usage(NULL);
+		    usage(NULL, 1);
 		}
 	    if (i == 1)
-		usage(NULL);
+		usage(NULL, 1);
 	} else {
 	    argcnt++;
 	    get_list(argv[0]);
diff --git a/man/fslsfonts.man b/man/fslsfonts.man
index 371d5ff..2c108ac 100644
--- a/man/fslsfonts.man
+++ b/man/fslsfonts.man
@@ -87,6 +87,9 @@ number of character specified by \fB\-w\fP \fIwidth\fP.
 .B \-u
 This option indicates that the output should be left unsorted.
 .TP 8
+.B \-help
+This option prints a usage message and exits.
+.TP 8
 .B \-version
 This option prints the program version and exits.
 .PP