lockfile.cpp

/**********************************************************************
 *  lockfile.cpp
 **********************************************************************
 * Copyright (C) 2014 MX Authors
 *
 * Authors: Adrian
 *          MX Linux <http://mxlinux.org>
 *
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 **********************************************************************/

#include "lockfile.h"

#include <sys/file.h>
#include <unistd.h>

LockFile::LockFile(const QString &file_name) { this->file_name = file_name; }

// checks if file is locked by another process (if locked by the same process returns false)
bool LockFile::isLocked()
{
    fd = open(file_name.toUtf8(), O_RDONLY);
    if (fd < -1) {
        perror("open");
        return false;
    }
    return (lockf(fd, F_TEST, 0) != 0);
}

bool LockFile::lock()
{
    fd = open(file_name.toUtf8(), O_WRONLY);
    if (fd < -1) {
        perror("open");
        return false;
    }
    // create a file lock
    return (lockf(fd, F_LOCK, 0) == 0);
}

bool LockFile::unlock()
{
    fd = open(file_name.toUtf8(), O_WRONLY);
    close(fd);
    return true;
}