package subprocess

import (

"io"

"os/exec"

)

// Thin wrapper around exec.Cmd. Takes care of pipe shutdown by

// keeping an internal reference to any created pipes. Whenever

// Cmd.Wait() is called, all created pipes are closed.

type Cmd struct {

*exec.Cmd

pipes []io.Closer

}

func (c *Cmd) StdoutPipe() (io.ReadCloser, error) {

stdout, err := c.Cmd.StdoutPipe()

c.pipes = append(c.pipes, stdout)

return stdout, err

}

func (c *Cmd) StderrPipe() (io.ReadCloser, error) {

stderr, err := c.Cmd.StderrPipe()

c.pipes = append(c.pipes, stderr)

return stderr, err

}

func (c *Cmd) StdinPipe() (io.WriteCloser, error) {

stdin, err := c.Cmd.StdinPipe()

c.pipes = append(c.pipes, stdin)

return stdin, err

}

func (c *Cmd) Wait() error {

for _, pipe := range c.pipes {

pipe.Close()

}

return c.Cmd.Wait()

}

func newCmd(cmd *exec.Cmd) *Cmd {

wrapped := &Cmd{Cmd: cmd}

return wrapped

}