access/main.go

package main

import (
	"fmt"
	"os"

	"golang.org/x/sys/unix"
)

func main() {
	if len(os.Args) != 2 {
		fmt.Fprintf(os.Stderr, "usage: access <path>\n")
		os.Exit(1)
	}

	filename := os.Args[1]
	if err := unix.Access(filename, unix.W_OK); err != nil {
		fmt.Printf("%v: %v\n", filename, err)
	}
}