gistfile1.txt

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

int main() {
  char cmd[128];
  int fd1,fd2,fd3,fd4,svs[2];
  printf("no sock_cloexec: %d\n",
         (fd1 = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)));
  printf("no sock_cloexec: %d\n",
         (fd2 = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)));
  printf("w/ sock_cloexec: %d\n",
         (fd3 = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_TCP)));
  printf("w/ sock_cloexec: %d\n",
         (fd3 = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC, IPPROTO_TCP)));
  printf("fcntl(%d, F_SETFD, FD_CLOEXEC)\n", fd2);
  fcntl(fd2, F_SETFD, FD_CLOEXEC);
  printf("w/ sock_cloexec/nonblock: %d\n",
         socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, IPPROTO_TCP));
  printf("w/ sock_cloexec/ndelay: %d\n",
         socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NDELAY, IPPROTO_TCP));
  printf("w/ sock_cloexec/nonblock/ndelay: %d\n",
         socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK|SOCK_NDELAY, IPPROTO_TCP));
  printf("w/ invalid: %d\n",
         socket(AF_INET, SOCK_STREAM|(SOCK_NDELAY<<1), IPPROTO_TCP));

  if(socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, svs))
    perror("socketpair");
  printf("socketpair([%d,%d])\n", svs[0], svs[1]);
  if(socketpair(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC, 0, svs))
    perror("socketpair");
  printf("socketpair([%d,%d])\n", svs[0], svs[1]);

  snprintf(cmd, sizeof(cmd), "/bin/pfiles %d", (int)getpid());
  system(cmd);
  return 0;
}