Zabbix

//go:build !windows

// +build !windows

​

/*

** Copyright (C) 2001-2025 Zabbix SIA

**

** This program is free software: you can redistribute it and/or modify it under the terms of

** the GNU Affero General Public License as published by the Free Software Foundation, version 3.

**

** 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 Affero General Public License for more details.

**

** You should have received a copy of the GNU Affero General Public License along with this program.

** If not, see <https://www.gnu.org/licenses/>.

**/

​

package pidfile

​

import (

    "fmt"

    "io"

    "os"

    "syscall"

)

​

func createPidFile(pid int, path string) (file *os.File, err error) {

    if path == "" {

        path = "/tmp/zabbix_agent2.pid"

    }

​

    flockT := syscall.Flock_t{

        Type:   syscall.F_WRLCK,

        Whence: io.SeekStart,

        Start:  0,

        Len:    0,

        Pid:    int32(pid),

    }

    if file, err = os.OpenFile(path, os.O_WRONLY|os.O_CREATE|syscall.O_CLOEXEC, 0644); nil != err {

        return nil, fmt.Errorf("cannot open PID file [%s]: %s", path, err.Error())

    }

    if err = syscall.FcntlFlock(file.Fd(), syscall.F_SETLK, &flockT); nil != err {

        file.Close()

        return nil, fmt.Errorf("Is this process already running? Could not lock PID file [%s]: %s",

            path, err.Error())

    }

    return

}