60 lines
1.5 KiB
C
60 lines
1.5 KiB
C
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/* Copyright (C) 1991, 1992, 1993, 1995 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Library General Public License as
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published by the Free Software Foundation; either version 2 of the
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License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Library General Public License for more details.
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You should have received a copy of the GNU Library General Public
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License along with the GNU C Library; see the file COPYING.LIB. If
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not, write to the Free Software Foundation, Inc., 675 Mass Ave,
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Cambridge, MA 02139, USA. */
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#include <ansidecl.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <limits.h>
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#include <unistd.h>
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/* Duplicate FD to FD2, closing the old FD2 and making FD2 be
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open the same file as FD is. Return FD2 or -1. */
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int
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DEFUN(__dup2, (fd, fd2), int fd AND int fd2)
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{
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int save;
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if (fd2 < 0
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#ifdef OPEN_MAX
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|| fd2 >= OPEN_MAX
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#endif
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)
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{
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errno = EBADF;
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return -1;
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}
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/* Check if FD is kosher. */
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if (fcntl (fd, F_GETFL) < 0)
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return -1;
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if (fd == fd2)
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return fd2;
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/* This is not atomic. */
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save = errno;
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(void) close (fd2);
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errno = save;
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return fcntl (fd, F_DUPFD, fd2);
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}
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weak_alias (__dup2, dup2)
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