#include "fd.h"

#include <fcntl.h>

/**
  @file fd.c
  @autor djb
  @source qmail
  @brief file descriptor manipulation
*/

int close(int __fd); /* we won't use unistd.h here */

int fd_copy(int to, int from)
{
  if (to == from) return 0;
  if (fcntl(from, F_GETFL, 0) == -1) return -1;
  close(to);
  if (fcntl(from, F_DUPFD, to) == -1) return -1;
  return 0;
}

int fd_move(int to, int from)
{
  if (to == from) return 0;
  if (fd_copy(to, from) == -1) return -1;
  close(from);
  return 0;
}

int fd_coe(int fd)
{
  return fcntl(fd, F_SETFD, 1);
}