ocaml/otherlibs/unix/dup2.c

45 lines
1.9 KiB
C

/**************************************************************************/
/* */
/* OCaml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. */
/* */
/* All rights reserved. This file is distributed under the terms of */
/* the GNU Lesser General Public License version 2.1, with the */
/* special exception on linking described in the file LICENSE. */
/* */
/**************************************************************************/
#define _GNU_SOURCE
#include <caml/mlvalues.h>
#include "unixsupport.h"
#include <fcntl.h>
CAMLprim value unix_dup2(value cloexec, value fd1, value fd2)
{
if (Int_val(fd2) == Int_val(fd1)) {
/* In this case, dup3 fails and dup2 does nothing. */
/* Just apply the cloexec flag to fd2, if it is given. */
if (Is_block(cloexec)) {
if (Bool_val(Field(cloexec, 0)))
unix_set_cloexec(Int_val(fd2), "dup2", Nothing);
else
unix_clear_cloexec(Int_val(fd2), "dup2", Nothing);
}
} else {
#ifdef HAS_DUP3
if (dup3(Int_val(fd1), Int_val(fd2),
unix_cloexec_p(cloexec) ? O_CLOEXEC : 0) == -1)
uerror("dup2", Nothing);
#else
if (dup2(Int_val(fd1), Int_val(fd2)) == -1) uerror("dup2", Nothing);
if (unix_cloexec_p(cloexec))
unix_set_cloexec(Int_val(fd2), "dup2", Nothing);
#endif
}
return Val_unit;
}