glibc/manual/examples/mkisock.c

/* Internet Socket Example
   Copyright (C) 1991-2019 Free Software Foundation, Inc.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; either version 2
   of the License, or (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, see <http://www.gnu.org/licenses/>.
*/

#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>

int
make_socket (uint16_t port)
{
  int sock;
  struct sockaddr_in name;

  /* Create the socket. */
  sock = socket (PF_INET, SOCK_STREAM, 0);
  if (sock < 0)
    {
      perror ("socket");
      exit (EXIT_FAILURE);
    }

  /* Give the socket a name. */
  name.sin_family = AF_INET;
  name.sin_port = htons (port);
  name.sin_addr.s_addr = htonl (INADDR_ANY);
  if (bind (sock, (struct sockaddr *) &name, sizeof (name)) < 0)
    {
      perror ("bind");
      exit (EXIT_FAILURE);
    }

  return sock;
}