mirror of
https://github.com/coreutils/coreutils.git
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d3f25798b9
Include <fcntl.h> and <unistd.h> unconditionally -- it seems to be ok to do this, these days.
68 lines
1.8 KiB
C
68 lines
1.8 KiB
C
/* stdopen.c - ensure that the three standard file descriptors are in use
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Copyright (C) 2005 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program 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
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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/* Written by Paul Eggert and Jim Meyering. */
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#if HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include "stdopen.h"
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <unistd.h>
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#include <errno.h>
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#ifndef STDIN_FILENO
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# define STDIN_FILENO 0
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#endif
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#ifndef STDOUT_FILENO
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# define STDOUT_FILENO 1
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#endif
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#ifndef STDERR_FILENO
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# define STDERR_FILENO 2
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#endif
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/* Try to ensure that each of the standard file numbers (0, 1, 2)
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is in use. Without this, each application would have to guard
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every call to open, dup, and fopen with tests to ensure they don't
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use one of the special file numbers when opening a user's file. */
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void
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stdopen (void)
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{
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int fd = dup (STDIN_FILENO);
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if (0 <= fd)
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close (fd);
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else if (errno == EBADF)
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fd = open ("/dev/null", O_WRONLY);
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if (STDIN_FILENO <= fd && fd <= STDERR_FILENO)
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{
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fd = open ("/dev/null", O_RDONLY);
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if (fd == STDOUT_FILENO)
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fd = dup (fd);
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if (STDERR_FILENO < fd)
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close (fd);
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}
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}
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