list_tar.go

package main

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

func ListTar(f io.Reader) error {
	tr := tar.NewReader(f)

	// Iterate through the files in the archive.
	for {
		hdr, err := tr.Next()
		if err == io.EOF {
			// end of tar archive
			break
		}
		if err != nil {
			return err
		}
		fmt.Printf("%s:\n", hdr.Name)
	}

	return nil
}

func main() {
	if len(os.Args) < 2 {
		fmt.Printf("To few args\n")
		os.Exit(1)
	}

	f, err := os.Open(os.Args[1])
	if err != nil {
		panic(err)
	}
	r, err := gzip.NewReader(f)
	if err != nil {
		panic(err)
	}
	err = ListTar(r)
	if err != nil {
		panic(err)
	}
}