misc/ioctltst.c

   1 #include <stdio.h>
   2 #include <errno.h>
   3 #include <sys/types.h>
   4 #include <sys/socket.h>
   5 #include <sys/ioctl.h>
   6 #include <net/if.h>
   7 #include <netinet/in.h>
   8
   9 /*
  10  * open a socket, get the process group information of the socket, and use the
  11  * socket to get the network interface configuration list
  12  */
  13 main()
  14 {
  15   int sock;
  16   int ioctl_result;
  17
  18   /* get a socket */
  19   sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
  20   if (sock < 0)
  21     {
  22       perror("Cannot create socket");
  23       exit(1);
  24     }
  25
  26   /* use ioctl() to get the process group information */
  27   {
  28     int get_process_group;
  29
  30     ioctl_result = ioctl(sock, SIOCGPGRP, (char *) &get_process_group);
  31
  32     if (ioctl_result < 0)
  33       {
  34         int my_errno = errno;
  35
  36         fprintf(stderr, "errno %d ", my_errno);
  37         perror("ioctl(get process group)");
  38       }
  39   }
  40
  41   /* use ioctl() to get the interface configuration list */
  42   {
  43     static struct ifconf ifc;   /* init to 0 */
  44
  45     ioctl_result = ioctl(sock, SIOCGIFCONF, (char *) &ifc);
  46
  47     if (ioctl_result < 0)
  48       {
  49         int my_errno = errno;
  50
  51         fprintf(stderr, "errno %d ", my_errno);
  52         perror("ioctl(get interface configuration list)");
  53       }
  54   }
  55 }