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/*
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* Copyright (c) 2004-2005, 2007, 2010, 2012-2014
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* Todd C. Miller <Todd.Miller@courtesan.com>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#include <sys/types.h>
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#include <fcntl.h>
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#include <limits.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#ifndef OPEN_MAX
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#define OPEN_MAX 256
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#endif
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/*
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* Close all file descriptors greater than or equal to lowfd.
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* This is the expensive (fallback) method.
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*/
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int
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closefrom(int lowfd)
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{
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long fd, maxfd;
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/*
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* Fall back on sysconf() or getdtablesize(). We avoid checking
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* resource limits since it is possible to open a file descriptor
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* and then drop the rlimit such that it is below the open fd.
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*/
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#ifdef HAVE_SYSCONF
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maxfd = sysconf(_SC_OPEN_MAX);
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#else
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maxfd = getdtablesize();
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#endif /* HAVE_SYSCONF */
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if (maxfd < 0)
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maxfd = OPEN_MAX;
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for (fd = lowfd; fd < maxfd; fd++) {
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#ifdef __APPLE__
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/* Avoid potential libdispatch crash when we close its fds. */
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(void) fcntl((int) fd, F_SETFD, FD_CLOEXEC);
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#else
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(void) close((int) fd);
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#endif
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}
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return 0;
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}
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