Prettify usage()

[babeltrace.git] / formats / registry.c

diff --git a/formats/registry.c b/formats/registry.c
index a6fd74b2bc5d3432ba0dae10eb0784753607e411..656d6360aca0030856c3a08830998cea1ea4119f 100644 (file)
--- a/formats/registry.c
+++ b/formats/registry.c
@@ -21,6 +21,11 @@
 #include <errno.h>
 #include <stdio.h>
 
+struct walk_data {
+       FILE *fp;
+       int iter;
+};
+
 static int init_done;
 void __attribute__((constructor)) format_init(void);
 void __attribute__((destructor)) format_finalize(void);
@@ -42,19 +47,27 @@ struct format *bt_lookup_format(GQuark qname)
 
 static void show_format(gpointer key, gpointer value, gpointer user_data)
 {
-       FILE *fp = user_data;
+       struct walk_data *data = user_data;
 
-       fprintf(fp, "format: %s\n",
+       fprintf(data->fp, "%s%s", data->iter ? ", " : "",
                g_quark_to_string((GQuark) (unsigned long) key));
+       data->iter++;
 }
 
 void bt_fprintf_format_list(FILE *fp)
 {
-       fprintf(fp, "Formats available:\n");
+       struct walk_data data;
+
+       data.fp = fp;
+       data.iter = 0;
+
+       fprintf(fp, "Formats available: ");
        if (!init_done)
                return;
-       g_hash_table_foreach(format_registry, show_format, fp);
-       fprintf(fp, "End of formats available.\n");
+       g_hash_table_foreach(format_registry, show_format, &data);
+       if (data.iter == 0)
+               fprintf(fp, "<none>");
+       fprintf(fp, ".\n");
 }
 
 int bt_register_format(struct format *format)