Using stdout and stdin from other programs in Golang

Golang program stdin stdout interaction.md

Go program interaction

Example of how to use stdout and stdin from other programs in golang

Requires go

Run

go run parentprocess.go

parentprocess.go

package main

import (
	"bufio"
	"io"
	"log"
	"os"
	"os/exec"
)

func main() {

	cmd := exec.Command("./subprocess.sh")
	cmd.Stderr = os.Stderr
	stdin, err := cmd.StdinPipe()
	if nil != err {
		log.Fatalf("Error obtaining stdin: %s", err.Error())
	}
	stdout, err := cmd.StdoutPipe()
	if nil != err {
		log.Fatalf("Error obtaining stdout: %s", err.Error())
	}
	reader := bufio.NewReader(stdout)
	go func(reader io.Reader) {
		scanner := bufio.NewScanner(reader)
		for scanner.Scan() {
			log.Printf("Reading from subprocess: %s", scanner.Text())
			stdin.Write([]byte("some sample text\n"))
		}
	}(reader)
	if err := cmd.Start(); nil != err {
		log.Fatalf("Error starting program: %s, %s", cmd.Path, err.Error())
	}
	cmd.Wait()

}

subprocess.sh

#!/bin/bash

echo "Enter some text:"
read -r input
echo "you typed: $input"