From 28f540f45bbacd939bfd07f213bcad2bf730b1bf Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Sat, 18 Feb 1995 01:27:10 +0000 Subject: initial import --- sysdeps/posix/dup2.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 sysdeps/posix/dup2.c (limited to 'sysdeps/posix/dup2.c') diff --git a/sysdeps/posix/dup2.c b/sysdeps/posix/dup2.c new file mode 100644 index 0000000000..c0c6b2a0f6 --- /dev/null +++ b/sysdeps/posix/dup2.c @@ -0,0 +1,59 @@ +/* Copyright (C) 1991, 1992, 1993, 1995 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +The GNU C Library is free software; you can redistribute it and/or +modify it under the terms of the GNU Library General Public License as +published by the Free Software Foundation; either version 2 of the +License, or (at your option) any later version. + +The GNU C Library 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include +#include +#include +#include +#include + + +/* Duplicate FD to FD2, closing the old FD2 and making FD2 be + open the same file as FD is. Return FD2 or -1. */ +int +DEFUN(__dup2, (fd, fd2), int fd AND int fd2) +{ + int save; + + if (fd2 < 0 +#ifdef OPEN_MAX + || fd2 >= OPEN_MAX +#endif +) + { + errno = EBADF; + return -1; + } + + /* Check if FD is kosher. */ + if (fcntl (fd, F_GETFL) < 0) + return -1; + + if (fd == fd2) + return fd2; + + /* This is not atomic. */ + + save = errno; + (void) close (fd2); + errno = save; + + return fcntl (fd, F_DUPFD, fd2); +} + +weak_alias (__dup2, dup2) -- cgit v1.2.3