62 lines
1.6 KiB
C
62 lines
1.6 KiB
C
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/*
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* Copyright (c) 2006 Darren Tucker
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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 <sys/stat.h>
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#include <fcntl.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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#define NUM_OPENS 10
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void
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fail(char *msg)
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{
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fprintf(stderr, "closefrom: %s\n", msg);
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exit(1);
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}
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int
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main(void)
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{
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int i, max, fds[NUM_OPENS];
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char buf[512];
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for (i = 0; i < NUM_OPENS; i++)
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if ((fds[i] = open("/dev/null", O_RDONLY)) == -1)
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exit(0); /* can't test */
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max = i - 1;
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/* should close last fd only */
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closefrom(fds[max]);
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if (close(fds[max]) != -1)
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fail("failed to close highest fd");
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/* make sure we can still use remaining descriptors */
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for (i = 0; i < max; i++)
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if (read(fds[i], buf, sizeof(buf)) == -1)
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fail("closed descriptors it should not have");
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/* should close all fds */
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closefrom(fds[0]);
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for (i = 0; i < NUM_OPENS; i++)
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if (close(fds[i]) != -1)
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fail("failed to close from lowest fd");
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return 0;
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}
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