summaryrefslogtreecommitdiffstats
path: root/c/src/lib/libc/dup2.c
blob: 21701bfd0d4bde27f568db5c8a1c809fcf8efed3 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
/*
 *  dup2() - POSIX 1003.1b 6.2.1 Duplicate an Open File Descriptor
 *
 *  COPYRIGHT (c) 1989-1999.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.OARcorp.com/rtems/license.html.
 *
 *  $Id$
 */

#include <unistd.h>
#include <fcntl.h>

#include "libio_.h"

int dup2(
  int fildes,
  int fildes2
)
{
  int          status;
  struct stat  buf;

  /*
   *  If fildes is not valid, then fildes2 should not be closed.
   */

  status = fstat( fildes, &buf );
  if ( status == -1 )
    return -1;

  /*
   *  If fildes2 is not valid, then we should not do anything either.
   */

  status = fstat( fildes2, &buf );
  if ( status == -1 )
    return -1;

  /*
   *  This fcntl handles everything else.
   */
  
  return fcntl( fildes, F_DUPFD, fildes2 );
}