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58 lines
1.5 KiB
C
58 lines
1.5 KiB
C
/* Duplicate an open file descriptor to a specified file descriptor.
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Copyright (C) 1999, 2004, 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 */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <errno.h>
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#include <fcntl.h>
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#include <unistd.h>
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#ifndef F_DUPFD
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static int
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dupfd (int fd, int desired_fd)
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{
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int duplicated_fd = dup (fd);
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if (duplicated_fd < 0 || duplicated_fd == desired_fd)
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return duplicated_fd;
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else
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{
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int r = dupfd (fd, desired_fd);
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int e = errno;
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close (duplicated_fd);
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errno = e;
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return r;
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}
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}
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#endif
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int
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dup2 (int fd, int desired_fd)
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{
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if (fd == desired_fd)
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return fd;
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close (desired_fd);
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#ifdef F_DUPFD
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return fcntl (fd, F_DUPFD, desired_fd);
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#else
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return dupfd (fd, desired_fd);
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#endif
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}
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