convert to multicall binary

cmd/multicall.c

@@ -0,0 +1,60 @@
+/*
+ * cmd/multicall.c
+ * Purpose: multi-call binary frontend
+ *
+ * Copyright (c) 2020 Ariadne Conill <ariadne@dereferenced.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * This software is provided 'as is' and without any warranty, express or
+ * implied.  In no event shall the authors be liable for any damages arising
+ * from the use of this software.
+ */
+
+#include <libgen.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "cmd/multicall.h"
+
+extern struct if_applet ifquery_applet;
+extern struct if_applet ifup_applet;
+extern struct if_applet ifdown_applet;
+
+struct if_applet *applet_table[] = {
+	&ifdown_applet,
+	&ifquery_applet,
+	&ifup_applet,
+};
+
+#define ARRAY_SIZE(x)	(sizeof(x) / sizeof(*x))
+
+int
+applet_cmp(const void *a, const void *b)
+{
+	const char *key = a;
+	const struct if_applet *applet = *(void **)b;
+
+	return strcmp(key, applet->name);
+}
+
+int
+main(int argc, char *argv[])
+{
+	char *argv0 = basename(argv[0]);
+	struct if_applet **app;
+
+	app = bsearch(argv0, applet_table,
+		      ARRAY_SIZE(applet_table), sizeof(*applet_table),
+		      applet_cmp);
+
+	if (app == NULL)
+	{
+		fprintf(stderr, "%s: applet not found\n", argv0);
+		return EXIT_FAILURE;
+	}
+
+	return (*app)->main(argc, argv);
+}