Golang : Gunzip file

This tutorial demonstrates how to g-unzip a gz file easily in Golang. It is a continuation from previous tutorial on how to unzip a zip archive.

gunzip.go

 package main

 import (
 "compress/gzip"
 "flag"
 "fmt"
 "io"
 "os"
 "strings"
 )

 func main() {

 flag.Parse() // get the arguments from command line

 filename := flag.Arg(0)

 if filename == "" {
 fmt.Println("Usage : gunzip sourcefile.gz")
 os.Exit(1)
 }

 gzipfile, err := os.Open(filename)

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 reader, err := gzip.NewReader(gzipfile)
 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }
 defer reader.Close()

 newfilename := strings.TrimSuffix(filename, ".gz")

 writer, err := os.Create(newfilename)

 if err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 defer writer.Close()

 if _, err = io.Copy(writer, reader); err != nil {
 fmt.Println(err)
 os.Exit(1)
 }

 }

Outputs (example) :

./gunzip

Usage : gunzip sourcefile.gz

This program will not produce any message upon successful decompression of gzipped file.