Written by Edd Turtle on gophercoding.com
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(Updated: )

Convert an io.ReadCloser to String

Using Go, we often make HTTP calls these days using net/http, which result in a response of type io.ReadCloser… which are hard to read for the layman (like me). What we really want to the response in the form of a string which we can read. This post will talk about how to convert these ReadCloser into strings.

First we’ll look at the problem, then we have two different solutions.

Problem:

Because ReadCloser is a struct object, we can’t print it out using fmt/log.

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package main

import (
	"fmt"
	"net/http"
)

func main() {
	response, _ := http.Get("https://gophercoding.com/site.webmanifest")
	fmt.Println(response.Body)
}

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$ go run ioread.go 
&{[] {0xc000096300} <nil> <nil>}

Solution 1: Buffer

Write the contents of the ReadCloser to an in-memory buffer.

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package main

import (
	"fmt"
	"net/http"
	"bytes"
)

func main() {
	response, _ := http.Get("https://gophercoding.com/site.webmanifest")

	buf := new(bytes.Buffer)
	buf.ReadFrom(response.Body)
	respBytes := buf.String()

	respString := string(respBytes)

	fmt.Printf(respString)
}

Solution 2: Ioutil

Use the helper package ioutil to read all the contents into a []byte array for us.

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package main

import (
	"fmt"
	"net/http"
	"io/ioutil"
)

func main() {
	response, _ := http.Get("https://gophercoding.com/site.webmanifest")

	respBytes, err := ioutil.ReadAll(response.Body)
	if err != nil {
		panic(err)
	}

	respString := string(respBytes)

	fmt.Printf(respString)
}

how to read io.readcloser as string

#readcloser#io#convert#string#conversion#ioutil#buffer#memory#http#net
Author Edd Turtle

Edd is a PHP and Go developer who enjoys blogging about his experiences, mostly about creating and coding new things he's working on and is a big beliver in open-source and Linux.

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