在单值上下文中使用多值

Question

I have a function returning 2 values: string and []string

func executeCmd(command, port string, hostname string, config *ssh.ClientConfig) (target string, splitOut []string) {

...
  return hostname, strings.Split(stdoutBuf.String(), " ")
}

This function is passed down to a go routine channel ch

  ch <- executeCmd(cmd, port, hostname, config)

I understand that when you want assign 2 or more values to a single variable, you need to create a structure and in case of go routine, use the structure to make a channel

    type results struct {
        target string
        output []string
    }
  ch := make(chan results, 10)

Being a beginner in GO, I don't understand what I am doing wrong. I have seen other people having similar issue as mine but unfortunately the answers provided did not make sense to me

Answer 1

The channel can only take one variable so you are right that you need to define a structure to hold you results, however, you are not actually using this to pass into your channel. You have two options, either modify executeCmd to return a results:

func executeCmd(command, port string, hostname string, config *ssh.ClientConfig) results {

...
  return results{
    target: hostname, 
    output: strings.Split(stdoutBuf.String(), " "),
  }
}

ch <- executeCmd(cmd, port, hostname, config)

Or leave executeCmd as it is and put the values returned into a struct after calling it:

func executeCmd(command, port string, hostname string, config *ssh.ClientConfig) (target string, splitOut []string) {

...
  return hostname, strings.Split(stdoutBuf.String(), " ")
}

hostname, output := executeCmd(cmd, port, hostname, config)
result := results{
  target: hostname, 
  output: strings.Split(stdoutBuf.String(), " "),
}
ch <- result