code: func sshParseShellCommand(command string, existing string) (ssh string, cmd string, needShell bool) {
  	ssh = existing
  	if cmdArgs := tools.QuotedFields(command); len(cmdArgs) > 0 {
  		needShell = true
  		ssh = cmdArgs[0]
  		cmd = command
  	}
  	return
  }
docs: // Parse command, and if it looks like a valid command, return the ssh binary
  // name, the command to run, and whether we need a shell.  If not, return
  // existing as the ssh binary name.