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1 /* ========================================================================
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2 * Copyright 1988-2006 University of Washington
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3 *
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4 * Licensed under the Apache License, Version 2.0 (the "License");
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5 * you may not use this file except in compliance with the License.
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6 * You may obtain a copy of the License at
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7 *
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8 * http://www.apache.org/licenses/LICENSE-2.0
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9 *
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10 *
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11 * ========================================================================
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12 */
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13
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14 /*
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15 * Program: Exclusive create of a file
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16 *
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17 * Author: Mark Crispin
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18 * Networks and Distributed Computing
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19 * Computing & Communications
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20 * University of Washington
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21 * Administration Building, AG-44
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22 * Seattle, WA 98195
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23 * Internet: MRC@CAC.Washington.EDU
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24 *
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25 * Date: 17 December 1999
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26 * Last Edited: 30 August 2006
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27 */
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28
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29 /* Exclusive create of a file
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30 * Accepts: file name
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31 * Return: T if success, NIL if failed, -1 if retry
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32 */
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33
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34 long crexcl (char *name)
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35 {
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36 int i;
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37 int mask = umask (0);
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38 long ret = LONGT;
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39 /* try to get the lock */
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40 if ((i = open (name,O_WRONLY|O_CREAT|O_EXCL,(int) shlock_mode)) < 0)
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41 ret = (errno == EEXIST) ? -1 : NIL;
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42 else close (i); /* made the file, now close it */
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43 umask (mask); /* restore previous mask */
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44 return LONGT; /* success */
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45 }
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