cdesktopenv/cde/programs/dtudcfonted/libfuty/lock.c

129 lines
2.5 KiB
C

/*
* CDE - Common Desktop Environment
*
* Copyright (c) 1993-2012, The Open Group. All rights reserved.
*
* These libraries and programs are free software; you can
* redistribute them and/or modify them under the terms of the GNU
* Lesser General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* These libraries and programs are distributed in the hope that
* they will be useful, but WITHOUT ANY WARRANTY; without even the
* implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with these libraries and programs; if not, write
* to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
* Floor, Boston, MA 02110-1301 USA
*/
/* $XConsortium: lock.c /main/5 1996/11/08 02:07:28 cde-fuj $ */
/*
* (c) Copyright 1995 FUJITSU LIMITED
* This is source code modified by FUJITSU LIMITED under the Joint
* Development Agreement for the CDEnext PST.
* This is unpublished proprietary source code of FUJITSU LIMITED
*/
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
#include "udcutil.h"
/*
* FileLock( fd )
* fd: file descripter
*
* lock a file by a writing mode
*
* normal end : 0
* abnormal end : -1
*
*/
int
FileLock( int fd )
{
struct flock flpar;
flpar.l_type = F_RDLCK;
flpar.l_start = 0;
flpar.l_len = 0;
flpar.l_whence = 0;
if ( fcntl( fd, F_SETLK, &flpar ) == -1 ) {
USAGE("Write lock not success \n" );
return -1;
}
return 0;
}
/*
* FileUnLock( fd )
*
* free a file by a writing mode
*
* normal end : 0
* abnormal end : -1
*/
int
FileUnLock( int fd )
{
struct flock flpar;
flpar.l_type = F_UNLCK;
flpar.l_start = 0;
flpar.l_len = 0;
flpar.l_whence = 0;
if ( fcntl( fd, F_SETLK, &flpar ) == -1 ){
USAGE("File unlock not success \n" );
return -1;
}
return 0;
}
/*
* isLock( fd )
*
* search whether file is locked by a writing mode
*
* 1 : file is locked by a writing mode
* 0 : file isn't locked by a writing mode
*/
int
isLock( int fd )
{
struct flock flpar;
flpar.l_type = F_WRLCK;
flpar.l_start = 0;
flpar.l_len = 0;
flpar.l_whence = 0;
if ( fcntl( fd, F_GETLK, &flpar ) == -1 ) {
USAGE("Inquiry of file lock not sucess \n" );
return -1;
}
if ( flpar.l_type == F_UNLCK ){
return 0 ;
} else {
return 1 ;
}
}