Golang Flock

flock.go

package main

// #include <sys/file.h>
import "C"

import (
	"fmt"
	"os"
	"os/exec"
)

func main() {
	fi, err := os.Create("lock")
	if err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
	defer fi.Close()
	fd := fi.Fd()
	returnCode := C.flock(C.int(fd), C.LOCK_EX)
	if returnCode < 0 {
		fmt.Println("Flock lock returned bad status: %d", returnCode)
		os.Exit(2)
	}
	if len(os.Args) > 1 {
		cmd := exec.Command(os.Args[1], os.Args[2:]...)
		cmd.Stdout = os.Stdout
		cmd.Stderr = os.Stderr
		cmd.Stdin = os.Stdin
		if err := cmd.Run(); err != nil {
			fmt.Println(err)
		}
	}
	returnCode = C.flock(C.int(fd), C.LOCK_UN)
	if returnCode < 0 {
		fmt.Println("Flock unlock returned bad status: %d", returnCode)
		os.Exit(2)
	}
}