88 lines
2.5 KiB
C
88 lines
2.5 KiB
C
/*
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* Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Högskolan
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* (Royal Institute of Technology, Stockholm, Sweden).
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#ifndef HAVE_FLOCK
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RCSID("$Id: flock.c,v 1.4 1999/12/02 16:58:46 joda Exp $");
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#include "roken.h"
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#define OP_MASK (LOCK_SH | LOCK_EX | LOCK_UN)
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int
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flock(int fd, int operation)
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{
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#if defined(HAVE_FCNTL) && defined(F_SETLK)
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struct flock arg;
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int code, cmd;
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arg.l_whence = SEEK_SET;
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arg.l_start = 0;
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arg.l_len = 0; /* means to EOF */
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if (operation & LOCK_NB)
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cmd = F_SETLK;
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else
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cmd = F_SETLKW; /* Blocking */
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switch (operation & OP_MASK) {
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case LOCK_UN:
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arg.l_type = F_UNLCK;
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code = fcntl(fd, F_SETLK, &arg);
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break;
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case LOCK_SH:
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arg.l_type = F_RDLCK;
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code = fcntl(fd, cmd, &arg);
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break;
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case LOCK_EX:
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arg.l_type = F_WRLCK;
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code = fcntl(fd, cmd, &arg);
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break;
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default:
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errno = EINVAL;
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code = -1;
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break;
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}
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return code;
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#else
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return -1;
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#endif
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}
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#endif
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