在前面的例子中，我们看看产生外部进程。 当需要一个运行的go进程可访问的外部进程时，我们就可以这样做。有时只是想用另一个(可能是非go)完全替换当前的go进程。可使用go的经典exec函数来实现。
在下面的例子将执行ls命令。 go需要一个我们想要执行的二进制的绝对路径，所以将使用exec.lookpath来找到它(可能是/bin/ls)。

所有的示例代码，都放在 f:\worksp\golang 目录下。安装go编程环境请参考：http://www.h3.com/go/go_environment.html

execing-processes.go的完整代码如下所示 -

package main

import "syscall"
import "os"
import "os/exec"

func main() {

    // for our example we'll exec `ls`. go requires an
    // absolute path to the binary we want to execute, so
    // we'll use `exec.lookpath` to find it (probably
    // `/bin/ls`).
    binary, lookerr := exec.lookpath("ls")
    if lookerr != nil {
        panic(lookerr)
    }

    // `exec` requires arguments in slice form (as
    // apposed to one big string). we'll give `ls` a few
    // common arguments. note that the first argument should
    // be the program name.
    args := []string{"ls", "-a", "-l", "-h"}

    // `exec` also needs a set of [environment variables](environment-variables)
    // to use. here we just provide our current
    // environment.
    env := os.environ()

    // here's the actual `syscall.exec` call. if this call is
    // successful, the execution of our process will end
    // here and be replaced by the `/bin/ls -a -l -h`
    // process. if there is an error we'll get a return
    // value.
    execerr := syscall.exec(binary, args, env)
    if execerr != nil {
        panic(execerr)
    }
}

执行上面代码，将得到以下输出结果 -

此程序仅限在 linux 类系统上执行。