Source from upstream; imap-2007f.tar.gz
MD5 2126fd125ea26b73b20f01fcd5940369
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Chris
51
src/mlock/Makefile
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51
src/mlock/Makefile
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# ========================================================================
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# Copyright 1988-2006 University of Washington
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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#
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# ========================================================================
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# Program: MLOCK Makefile
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#
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# Author: Mark Crispin
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# Networks and Distributed Computing
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# Computing & Communications
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# University of Washington
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# Administration Building, AG-44
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# Seattle, WA 98195
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# Internet: MRC@CAC.Washington.EDU
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#
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# Date: 8 February 1999
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# Last Edited: 30 August 2006
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C = ../c-client
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SHELL = /bin/sh
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# Get local definitions from c-client directory
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CC = `cat $C/CCTYPE`
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CFLAGS = `cat $C/CFLAGS`
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all: mlock
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mlock: mlock.o
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$(CC) $(CFLAGS) -o mlock mlock.o
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install: mlock
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chgrp mail mlock
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chmod 3711 mlock
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cp -p mlock /etc/mlock
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clean:
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rm -f *.o mlock || true
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# A monument to a hack of long ago and far away...
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love:
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@echo 'not war?'
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175
src/mlock/mlock.c
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175
src/mlock/mlock.c
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/* ========================================================================
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* Copyright 1988-2008 University of Washington
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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*
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* ========================================================================
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*/
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/*
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* Program: Standalone Mailbox Lock program
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*
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* Author: Mark Crispin
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* Networks and Distributed Computing
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* Computing & Communications
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* University of Washington
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* Administration Building, AG-44
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* Seattle, WA 98195
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* Internet: MRC@CAC.Washington.EDU
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*
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* Date: 8 February 1999
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* Last Edited: 3 March 2008
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*/
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#include <errno.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <sysexits.h>
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#include <syslog.h>
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#include <grp.h>
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#include <sys/types.h>
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#include <sys/file.h>
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#include <sys/stat.h>
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#include <sys/param.h>
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#include <stdlib.h>
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#include <netdb.h>
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#include <ctype.h>
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#include <string.h>
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#define LOCKTIMEOUT 5 /* lock timeout in minutes */
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#define LOCKPROTECTION 0664
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#ifndef MAXHOSTNAMELEN /* Solaris still sucks */
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#define MAXHOSTNAMELEN 256
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#endif
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/* Fatal error
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* Accepts: Message string
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* exit code
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* Returns: code
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*/
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int die (char *msg,int code)
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{
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syslog (LOG_NOTICE,"(%u) %s",code,msg);
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write (1,"?",1); /* indicate "impossible" failure */
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return code;
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}
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int main (int argc,char *argv[])
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{
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int ld,i;
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int tries = LOCKTIMEOUT * 60 - 1;
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char *s,*dir,*file,*lock,*hitch,tmp[1024];
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size_t dlen,len;
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struct stat sb,fsb;
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struct group *grp = getgrnam ("mail");
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/* get syslog */
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openlog (argv[0],LOG_PID,LOG_MAIL);
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if (!grp || (grp->gr_gid != getegid ()))
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return die ("not setgid mail",EX_USAGE);
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if (argc != 3) return die ("invalid arguments",EX_USAGE);
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for (s = argv[1]; *s; s++)
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if (!isdigit (*s)) return die ("invalid fd",EX_USAGE);
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/* find directory */
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if ((*argv[2] != '/') || !(file = strrchr (argv[2],'/')) || !file[1])
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return die ("invalid path",EX_USAGE);
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/* calculate lengths of directory and file */
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if (!(dlen = file - argv[2])) dlen = 1;
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len = strlen (++file);
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/* make buffers */
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dir = (char *) malloc (dlen + 1);
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lock = (char *) malloc (len + 6);
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hitch = (char *) malloc (len + 6 + 40 + MAXHOSTNAMELEN);
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if (!dir || !lock || !hitch) return die ("malloc failure",errno);
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strncpy (dir,argv[2],dlen); /* connect to desired directory */
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dir[dlen] = '\0';
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printf ("dir=%s, file=%s\n",dir,file);
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chdir (dir);
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/* get device/inode of file descriptor */
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if (fstat (atoi (argv[1]),&fsb)) return die ("fstat failure",errno);
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/* better be a regular file */
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if ((fsb.st_mode & S_IFMT) != S_IFREG)
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return die ("fd not regular file",EX_USAGE);
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/* now get device/inode of file */
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if (lstat (file,&sb)) return die ("lstat failure",errno);
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/* does it match? */
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if ((sb.st_mode & S_IFMT) != S_IFREG)
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return die ("name not regular file",EX_USAGE);
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if ((sb.st_dev != fsb.st_dev) || (sb.st_ino != fsb.st_ino))
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return die ("fd and name different",EX_USAGE);
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/* build lock filename */
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sprintf (lock,"%s.lock",file);
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if (!lstat (lock,&sb) && ((sb.st_mode & S_IFMT) != S_IFREG))
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return die ("existing lock not regular file",EX_NOPERM);
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do { /* until OK or out of tries */
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if (!stat (lock,&sb) && (time (0) > (sb.st_ctime + LOCKTIMEOUT * 60)))
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unlink (lock); /* time out lock if enough time has passed */
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/* SUN-OS had an NFS
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* As kludgy as an albatross;
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* And everywhere that it was installed,
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* It was a total loss.
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* -- MRC 9/25/91
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*/
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/* build hitching post file name */
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sprintf (hitch,"%s.%lu.%lu.",lock,(unsigned long) time (0),
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(unsigned long) getpid ());
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len = strlen (hitch); /* append local host name */
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gethostname (hitch + len,MAXHOSTNAMELEN);
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/* try to get hitching-post file */
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if ((ld = open (hitch,O_WRONLY|O_CREAT|O_EXCL,LOCKPROTECTION)) >= 0) {
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/* make sure others can break the lock */
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chmod (hitch,LOCKPROTECTION);
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/* get device/inode of hitch file */
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if (fstat (ld,&fsb)) return die ("hitch fstat failure",errno);
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close (ld); /* close the hitching-post */
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/* Note: link() may return an error even if it actually succeeded. So we
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* always check for success via the link count, and ignore the error if
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* the link count is right.
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*/
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/* tie hitching-post to lock */
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i = link (hitch,lock) ? errno : 0;
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/* success if link count now 2 */
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if (stat (hitch,&sb) || (sb.st_nlink != 2) ||
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(fsb.st_dev != sb.st_dev) || (fsb.st_ino != sb.st_ino)) {
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ld = -1; /* failed to hitch */
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if (i == EPERM) { /* was it because links not allowed? */
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/* Probably a FAT filesystem on Linux. It can't be NFS, so try
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* creating the lock file directly.
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*/
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if ((ld = open (lock,O_WRONLY|O_CREAT|O_EXCL,LOCKPROTECTION)) >= 0) {
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/* get device/inode of lock file */
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if (fstat (ld,&fsb)) return die ("lock fstat failure",errno);
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close (ld); /* close the file */
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}
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/* give up immediately if protection failure */
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else if (errno != EEXIST) tries = 0;
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}
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}
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unlink (hitch); /* flush hitching post */
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}
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/* give up immediately if protection failure */
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else if (errno == EACCES) tries = 0;
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if (ld < 0) { /* lock failed */
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if (tries--) sleep (1); /* sleep 1 second and try again */
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else {
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write (1,"-",1); /* hard failure */
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return EX_CANTCREAT;
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}
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}
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} while (ld < 0);
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write (1,"+",1); /* indicate that all is well */
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read (0,tmp,1); /* read continue signal from parent */
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/* flush the lock file */
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if (!stat (lock,&sb) && (fsb.st_dev == sb.st_dev) &&
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(fsb.st_ino == sb.st_ino)) unlink (lock);
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else syslog (LOG_NOTICE,"lock file %s/%s changed dev/inode",dir,lock);
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return EX_OK;
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}
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