getifaddrs(3)              Library Functions Manual              getifaddrs(3)

<?><?><?>
       getifaddrs, freeifaddrs - <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>

LIBRARY
       Standard C library (libc, -lc)

<?><?><?><?><?><?><?><?><?>
       #include <sys/types.h>
       #include <ifaddrs.h>

       int getifaddrs(struct ifaddrs **ifap);
       void freeifaddrs(struct ifaddrs *ifa);

<?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> getifaddrs() <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?> <?><?><?><?><?><?><?><?>,
       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?>, <?> <?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?><?><?><?><?> <?>
       *ifap. <?><?><?><?><?><?> <?><?><?><?><?><?><?> <?><?>
       <?><?><?><?><?><?><?><?> ifaddrs:

           struct ifaddrs {
               struct ifaddrs  *ifa_next;    /* <?><?><?><?>. <?><?><?><?><?><?><?> <?> <?><?><?><?><?><?> */
               char            *ifa_name;    /* <?><?><?> <?><?><?><?><?><?><?><?><?><?> */
               unsigned int     ifa_flags;   /* <?><?><?><?><?> <?><?> SIOCGIFFLAGS */
               struct sockaddr *ifa_addr;    /* <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?> */
               struct sockaddr *ifa_netmask; /* <?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?> */
               union {
                   struct sockaddr *ifu_broadaddr;
                                    /* <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?> */
                   struct sockaddr *ifu_dstaddr;
                                    /* <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>-<?><?><?><?><?> */
               } ifa_ifu;
           #define              ifa_broadaddr ifa_ifu.ifu_broadaddr
           #define              ifa_dstaddr   ifa_ifu.ifu_dstaddr
               void            *ifa_data;    /* <?><?><?><?>. <?><?><?><?><?><?> <?><?><?> <?><?><?><?><?><?> */
           };

       <?> <?><?><?><?> ifa_next <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?> <?><?><?> NULL,
       <?><?><?><?> <?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?> <?><?><?><?><?><?>.

       <?><?><?><?> ifa_name <?><?><?><?><?><?><?><?><?> <?><?> <?><?><?>
       <?><?><?><?><?><?><?><?><?><?>
       (<?><?><?><?><?><?><?><?><?><?><?><?><?><?><?> null).

       <?> <?><?><?><?> ifa_flags <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>,
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?> SIOCGIFFLAGS
       ioctl(2) (<?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?> netdevice(7)).

       <?><?><?><?> ifa_addr <?><?><?><?><?><?><?><?><?> <?><?>
       <?><?><?><?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?> (<?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?> sa_family).
       <?><?><?> <?><?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> null.

       <?><?><?><?> ifa_netmask <?><?><?><?><?><?><?><?><?> <?><?>
       <?><?><?><?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?> <?><?><?><?> <?><?><?> ifa_addr (<?><?><?><?> <?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?>). <?><?><?> <?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?> null.

       <?> <?><?><?><?><?><?><?><?><?><?><?> <?><?> <?><?><?><?><?><?><?>
       <?><?><?><?><?> IFF_BROADCAST <?><?><?> IFF_POINTOPOINT <?> ifa_flags
       (<?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?>-<?><?> <?><?><?><?>), <?> ifa_broadaddr <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
       ifa_addr (<?><?><?><?> <?><?> <?><?><?><?><?><?><?><?><?><?><?><?> <?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>) <?><?><?>
       ifa_dstaddr <?><?><?><?><?> <?><?><?><?><?><?><?><?><?> <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?> <?><?><?><?><?>-<?><?><?><?><?>.

       <?><?><?><?> ifa_data <?><?><?><?><?><?><?><?><?> <?><?>
       <?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>,
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?>; <?><?><?> <?><?><?><?> <?><?><?><?><?>
       <?><?><?><?> <?><?><?><?><?> NULL, <?><?><?><?> <?><?><?><?><?><?>
       <?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?> <?><?><?>.

       <?><?><?><?><?><?> <?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?><?><?> getifaddrs(),
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?> <?>
       <?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?><?> <?>
       <?><?><?><?><?><?><?> freeifaddrs(), <?><?><?><?><?> <?><?><?><?><?><?>
       <?><?> <?><?><?><?><?>.

<?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       On success, getifaddrs()  returns zero; on error, -1 is returned, and
       errno is set to indicate the error.

<?><?><?><?><?><?>
       <?><?><?><?><?><?><?> getifaddrs() <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?> <?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?> errno
       <?><?><?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?><?><?><?> <?>
       socket(2), bind(2), getsockname(2), recvmsg(2), sendto(2), malloc(3)
       <?><?><?> realloc(3).

<?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> <?> attributes(7).

       +----------------------------+----------------------------------------------------------+--------------------------+
       |<?><?><?><?><?><?><?><?><?> | <?><?><?><?><?><?><?>                                    | <?><?><?><?><?><?><?><?> |
       +----------------------------+----------------------------------------------------------+--------------------------+
       |getifaddrs(), freeifaddrs() | <?><?><?><?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?> | MT-Safe                  |
       +----------------------------+----------------------------------------------------------+--------------------------+
<?><?><?><?><?><?><?><?><?>
       None.

<?><?><?><?><?><?><?>
       This function first appeared in BSDi and is present on the BSD systems,
       but with slightly different semantics documented--returning one entry
       per interface, not per address.  This means ifa_addr and other fields
       can actually be NULL if the interface has no address, and no link-level
       address is returned if the interface has an IP address assigned.  Also,
       the way of choosing either ifa_broadaddr or ifa_dstaddr differs on
       various systems.

       getifaddrs()  first appeared in glibc 2.3, but before glibc 2.3.3, the
       implementation supported only IPv4 addresses; IPv6 support was added in
       glibc 2.3.3.  Support of address families other than IPv4 is available
       only on kernels that support netlink.

<?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?><?><?> <?> Linux,
       <?><?><?><?><?><?>, <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       IPv4 <?> IPv6, <?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?>, <?><?> <?><?><?><?><?> <?><?><?><?>
       <?><?><?><?> <?><?><?><?><?> AF_PACKET <?><?>
       <?><?><?><?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?> <?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?>. <?> <?><?><?><?>
       <?><?><?><?><?><?> <?><?><?><?> ifa_data <?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?> <?><?> struct
       rtnl_link_stats, <?><?><?><?><?><?><?><?><?><?><?><?> <?>
       <linux/if_link.h> (<?> Linux 2.4 <?> <?><?><?><?><?> -- struct
       net_device_stats, <?><?><?><?><?><?><?><?><?><?> <?>
       <linux/netdevice.h>), <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?> <?><?><?><?><?><?><?><?><?><?>.

<?><?><?><?><?><?><?>
       <?> <?><?><?><?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?> getifaddrs(), freeifaddrs(),
       <?> getnameinfo(3). <?><?><?> <?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?><?>:

           $ ./a.out
           lo       AF_PACKET (17)
                           tx_packets =        524; rx_packets =        524
                           tx_bytes   =      38788; rx_bytes   =      38788
           wlp3s0   AF_PACKET (17)
                           tx_packets =     108391; rx_packets =     130245
                           tx_bytes   =   30420659; rx_bytes   =   94230014
           em1      AF_PACKET (17)
                           tx_packets =          0; rx_packets =          0
                           tx_bytes   =          0; rx_bytes   =          0
           lo       AF_INET (2)
                           <?><?><?><?><?>: <127.0.0.1>
           wlp3s0   AF_INET (2)
                           <?><?><?><?><?>: <192.168.235.137>
           lo       AF_INET6 (10)
                           <?><?><?><?><?>: <::1>
           wlp3s0   AF_INET6 (10)
                           <?><?><?><?><?>: <fe80::7ee9:d3ff:fef5:1a91%wlp3s0>

   <?><?><?><?><?><?><?><?> <?><?><?> <?><?><?><?><?><?><?><?><?>
       #define _GNU_SOURCE     /* To get defns of NI_MAXSERV and NI_MAXHOST */
       #include <arpa/inet.h>
       #include <sys/socket.h>
       #include <netdb.h>
       #include <ifaddrs.h>
       #include <stdio.h>
       #include <stdlib.h>
       #include <unistd.h>
       #include <linux/if_link.h>

       int main(int argc, char *argv[])
       {
           struct ifaddrs *ifaddr;
           int family, s;
           char host[NI_MAXHOST];

           if (getifaddrs(&ifaddr) == -1) {
               perror("getifaddrs");
               exit(EXIT_FAILURE);
           }

           /* Walk through linked list, maintaining head pointer so we
              can free list later. */

           for (struct ifaddrs *ifa = ifaddr; ifa != NULL;
                    ifa = ifa->ifa_next) {
               if (ifa->ifa_addr == NULL)
                   continue;

               family = ifa->ifa_addr->sa_family;

               /* Display interface name and family (including symbolic
                  form of the latter for the common families). */

               printf("%-8s %s (%d)\n",
                      ifa->ifa_name,
                      (family == AF_PACKET) ? "AF_PACKET" :
                      (family == AF_INET) ? "AF_INET" :
                      (family == AF_INET6) ? "AF_INET6" : "???",
                      family);

               /* For an AF_INET* interface address, display the address. */

               if (family == AF_INET || family == AF_INET6) {
                   s = getnameinfo(ifa->ifa_addr,
                           (family == AF_INET) ? sizeof(struct sockaddr_in) :
                                                 sizeof(struct sockaddr_in6),
                           host, NI_MAXHOST,
                           NULL, 0, NI_NUMERICHOST);
                   if (s != 0) {
                       printf("getnameinfo() failed: %s\n", gai_strerror(s));
                       exit(EXIT_FAILURE);
                   }

                   printf("\t\taddress: <%s>\n", host);

               } else if (family == AF_PACKET && ifa->ifa_data != NULL) {
                   struct rtnl_link_stats *stats = ifa->ifa_data;

                   printf("\t\ttx_packets = %10u; rx_packets = %10u\n"
                          "\t\ttx_bytes   = %10u; rx_bytes   = %10u\n",
                          stats->tx_packets, stats->rx_packets,
                          stats->tx_bytes, stats->rx_bytes);
               }
           }

           freeifaddrs(ifaddr);
           exit(EXIT_SUCCESS);
       }

<?><?>. <?><?><?><?><?>
       bind(2), getsockname(2), socket(2), packet(7), ifconfig(8)

<?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?> <?><?><?><?><?><?><?> <?><?><?><?>
       <?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?> <?><?><?>
       <?><?><?><?><?><?> Azamat Hackimov <azamat.hackimov@gmail.com>, Dmitry
       Bolkhovskikh <d20052005@yandex.ru>, Vladislav
       <ivladislavefimov@gmail.com>, Yuri Kozlov <yuray@komyakino.ru> <?>
       <?><?><?><?> <?><?><?><?><?><?> <pavia00@gmail.com>

       <?><?><?><?> <?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?><?><?>;
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?> GNU
       <?><?><?><?><?><?> 3 <https://www.gnu.org/licenses/gpl-3.0.html>
       <?><?><?> <?><?><?><?><?> <?><?><?><?><?><?><?>, <?><?><?><?><?>
       <?><?><?><?><?><?> <?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?>. <?><?> <?><?>
       <?><?><?><?><?> <?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?><?><?><?><?>.

       <?><?><?><?> <?><?> <?><?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?>
       <?> <?><?><?><?><?><?><?><?> <?><?><?><?> <?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?><?><?><?><?><?>, <?><?><?><?><?><?><?><?><?><?>,
       <?><?><?><?><?><?><?><?><?> <?><?><?><?><?><?><?><?><?><?><?>
       <?><?><?><?><?><?> <?><?> <man-pages-ru-talks@lists.sourceforge.net>.

Linux man-pages 6.06  31 <?><?><?><?><?><?><?> 2023 <?>.         getifaddrs(3)