libnl  3.3.0
nl-link-name2ifindex.c
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 
15 #include <linux/netlink.h>
16 
17 static void print_usage(void)
18 {
19  printf("Usage: nl-link-name2ifindex <name>\n");
20  exit(0);
21 }
22 
23 int main(int argc, char *argv[])
24 {
25  struct nl_sock *sock;
26  struct nl_cache *link_cache;
27  uint32_t ifindex;
28 
29  if (argc < 2)
30  print_usage();
31 
32  sock = nl_cli_alloc_socket();
33  nl_cli_connect(sock, NETLINK_ROUTE);
34  link_cache = nl_cli_link_alloc_cache(sock);
35 
36  if (!(ifindex = rtnl_link_name2i(link_cache, argv[1])))
37  nl_cli_fatal(ENOENT, "Interface \"%s\" does not exist",
38  argv[1]);
39 
40  printf("%u\n", ifindex);
41 
42  return 0;
43 }
void nl_cli_fatal(int err, const char *fmt,...)
Print error message and quit application.
Definition: utils.c:71