Exec a command in golang and pass an input to a command using stdin

main.go

package main

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

func main() {

    // passo un comando e una stringa di input per esso
    // voglio passare da stdin per evitare di dover fare escaping
    // in bash
    shellout, err := Shellout("./test-input.sh", "{ \"id\"=\"123\" }")
    if err != nil {
        log.Println("Error:", err.Error())
    }   
    log.Println("output: ", shellout)
}

func Shellout(command string, commandInput string) (string, error) {

    cmd := exec.Command(command)
    log.Printf("shellout %q %q", command, commandInput)

    cmd.Stdin = strings.NewReader(commandInput)

    output, err := cmd.Output()
    if err != nil {
        return "", err 
    }   
    str := string(output)
    return str, err 
}

test-input.sh

#!/bin/bash
#
# $ echo "Ciao" | ./test-input.sh
# test: Ciao
#
read
echo "$REPLY"
while read line
do
  echo "$line"
done < "/dev/stdin"