code: func parseExec(opts execOptions, configFile *configfile.ConfigFile) *types.ExecConfig {
  	execConfig := &types.ExecConfig{
  		User:       opts.user,
  		Privileged: opts.privileged,
  		Tty:        opts.tty,
  		Cmd:        opts.command,
  		Detach:     opts.detach,
  		Env:        opts.env.GetAll(),
  		WorkingDir: opts.workdir,
  	}
  
  	// If -d is not set, attach to everything by default
  	if !opts.detach {
  		execConfig.AttachStdout = true
  		execConfig.AttachStderr = true
  		if opts.interactive {
  			execConfig.AttachStdin = true
  		}
  	}
  
  	if opts.detachKeys != "" {
  		execConfig.DetachKeys = opts.detachKeys
  	} else {
  		execConfig.DetachKeys = configFile.DetachKeys
  	}
  	return execConfig
  }
docs: // parseExec parses the specified args for the specified command and generates
  // an ExecConfig from it.