1 /*
2  * src/nl-link-name2ifindex.c     Transform a interface name to its index
3  *
4  *	This library is free software; you can redistribute it and/or
5  *	modify it under the terms of the GNU Lesser General Public
6  *	License as published by the Free Software Foundation version 2.1
7  *	of the License.
8  *
9  * Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
10  */
11 
12 #include <netlink/cli/utils.h>
13 #include <netlink/cli/link.h>
14 
print_usage(void)15 static void print_usage(void)
16 {
17 	printf("Usage: nl-link-ifindex2name <ifindex>\n");
18 	exit(0);
19 }
20 
main(int argc,char * argv[])21 int main(int argc, char *argv[])
22 {
23 	struct nl_sock *sock;
24 	struct nl_cache *link_cache;
25 	uint32_t ifindex;
26 
27 	if (argc < 2)
28 		print_usage();
29 
30 	sock = nl_cli_alloc_socket();
31 	nl_cli_connect(sock, NETLINK_ROUTE);
32 	link_cache = nl_cli_link_alloc_cache(sock);
33 
34 	if (!(ifindex = rtnl_link_name2i(link_cache, argv[1])))
35 		nl_cli_fatal(ENOENT, "Interface \"%s\" does not exist",
36 			     argv[1]);
37 
38 	printf("%u\n", ifindex);
39 
40 	return 0;
41 }
42