func (c *Cmd) Run() error {
	if err := c.Start(); err != nil {
		return err
	}
	return c.Wait()
}
func (c *Cmd) Run() error {
	if err := c.Start(); err != nil {
		return err
	}
	return c.Wait()
}
// Run starts the specified command and waits for it to complete.
//
// The returned error is nil if the command runs, has no problems
// copying stdin, stdout, and stderr, and exits with a zero exit
// status.
//
// If the command starts but does not complete successfully, the error is of
// type *ExitError. Other error types may be returned for other situations.