Catching the std output of a non stopping command

Getting Help Code Review
1

I aware we can collect the std returned command as:

package main

import (
    "fmt"
    "log"
    "os/exec"
)

func main() {
    out, err := exec.Command("date").Output()
    if err != nil {
        log.Fatal(err)
    }
    fmt.Printf("The date is %s\n", string(out))
}

Or something as:

package main

import (
	"bytes"
	"fmt"
	"log"
	"os/exec"
	"strings"
)

func main() {
	cmd := exec.Command("tr", "a-z", "A-Z")
	cmd.Stdin = strings.NewReader("some input")
	var out bytes.Buffer
	cmd.Stdout = &out
	err := cmd.Run()
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("in all caps: %q\n", out.String())
}

But this is usually happening for the commands that complete, return an output and exit.

In my case, I’ve a command, from a running server, that is keep providing logs to the std, something as:

waLog.Stdout("Client", "ERROR", true)

Part of the output is below:

enter image description here

How can I catch this output inside my code, something like cmd.Stdout above?

2

You could specify a different “io.writer” to handle your output