ReadFull in Go

Posted by GoDoc
Public (Editable by Users)

ReadFull reads exactly len(buf) bytes from r into buf. It returns the number of bytes copied and an error if fewer bytes were read. The error is EOF only if no bytes were read. If an EOF happens after reading some but not all the bytes, ReadFull returns ErrUnexpectedEOF. On return, n == len(buf) if and only if err == nil. If r returns an error having read at least len(buf) bytes, the error is dropped.

Go
Edit 
package main

import (
	"fmt"
	"io"
	"log"
	"strings"
)

func main() {
	r := strings.NewReader("some io.Reader stream to be read\n")

	buf := make([]byte, 4)
	if _, err := io.ReadFull(r, buf); err != nil {
		log.Fatal(err)
	}
	fmt.Printf("%s\n", buf)

	// minimal read size bigger than io.Reader stream
	longBuf := make([]byte, 64)
	if _, err := io.ReadFull(r, longBuf); err != nil {
		fmt.Println("error:", err)
	}
}