Mastering Go - Second Edition

Reading a text file line by line

Going line by line is the most common method of reading a text file. This is the main reason that it is being shown first. The Go code of byLine.go, which will be presented in three parts, will help you to understand the technique.

The first code segment from byLine.go is shown in the following Go code:

package main 
 
import ( 
    "bufio" 
    "flag" 
    "fmt" 
    "io" 
    "os" 
) 

As you can see by the presence of the bufio package, we will use buffered input.

The second part of byLine.go contains the following Go code:

func lineByLine(file string) error { var err error f, err := os.Open(file) if err != nil { return err } defer f.Close() r := bufio.NewReader(f) for { line, err := r.ReadString('\n') if err == io.EOF { break } else ...