Tar and Un-tar Gzip files in Golang

zipper.go

package main

import (
	"archive/tar"
	"compress/gzip"
	"io"
	"io/ioutil"
	"log"
	"os"
	"strings"
)

func walk(path, r string, tw *tar.Writer) error {
	if tw == nil {
		panic("tw must not be nil")
	}

	f, err := os.Open(path)
	if err != nil {
		return err
	}
	defer f.Close()

	i, err := f.Stat()
	if err != nil {
		return err
	}

	h, err := tar.FileInfoHeader(i, "")
	if err != nil {
		return err
	}
	h.Name = strings.TrimPrefix(path, r)

	if err = tw.WriteHeader(h); err != nil {
		return err
	}

	if i.IsDir() {
		fs, err := ioutil.ReadDir(path)
		if err != nil {
			return err
		}

		for i := range fs {
			p := path + "/" + fs[i].Name()
			if err = walk(p, r, tw); err != nil {
				return err
			}
		}

		return nil
	}

	_, err = io.Copy(tw, f)
	return err
}

func main() {
	log.SetFlags(log.Lshortfile)

	l := len(os.Args)
	if l < 3 {
		log.Fatal("Usage: zipper <source file>... <dist file>.tar.gz")
	}

	fs := os.Args[1 : l-1]
	dist, err := os.Create(os.Args[l-1])
	if err != nil {
		log.Fatalln(err)
	}
	defer dist.Close()

	gz := gzip.NewWriter(dist)
	tw := tar.NewWriter(gz)

	for i := range fs {
		info, err := os.Stat(fs[i])
		if err != nil {
			log.Println(err)
			continue
		}

		r := strings.TrimSuffix(fs[i], "/")
		r = strings.TrimSuffix(r, info.Name())
		err = walk(fs[i], r, tw)
		if err != nil {
			log.Print(err)
		}
	}

	if err = tw.Close(); err != nil {
		log.Print(err)
	}

	if err = gz.Close(); err != nil {
		log.Print(err)
	}
}

zipper_no_dir.go

package main

import (
	"archive/tar"
	"compress/gzip"
	"io"
	"log"
	"os"
)

func main() {
	log.SetFlags(log.Lshortfile)

	l := len(os.Args)
	if l < 3 {
		log.Fatal("Usage: zipper <source file>... <dist file>.tar.gz")
	}

	fs := os.Args[1 : l-1]
	dist, err := os.Create(os.Args[l-1])
	if err != nil {
		log.Fatalln(err)
	}
	defer dist.Close()

	gz := gzip.NewWriter(dist)
	defer gz.Close()

	tw := tar.NewWriter(gz)
	defer tw.Close()

	for i := range fs {
		f, err := os.Open(fs[i])
		if err != nil {
			log.Println(err)
			continue
		}
		defer f.Close()

		info, err := f.Stat()
		if err != nil {
			log.Println(err)
			continue
		}

		h, err := tar.FileInfoHeader(info, "")
		if err != nil {
			log.Println(err)
			continue
		}

		if err = tw.WriteHeader(h); err != nil {
			log.Println(err)
			continue
		}

		if _, err = io.Copy(tw, f); err != nil {
			log.Println(err)
		}
	}
}