How to work with tar command using golang exec.Cmd - go

Question

I have a tar.gz file and i need to unpack it using golang.
I've tried libs like "archive/tar" but they gave me error: archive/tar: invalid tar header. Now my idea was to use exec to run tar command and unpack tarball, but it always exits with code 2.
My code:
func unpack(tarName string) error {
path, _ := os.Getwd()
//err := Untar(path+"/"+tarName, path+"/")
fmt.Printf(path + "/" + tarName)
cmd := exec.Command("tar", "-xfv", path+"/"+tarName)
cmd.Stdout = os.Stdout
err := cmd.Run()
return err
}

Answer 1

If you are trying to compress tar.gz file you need first to decompress gzip.
import (
"archive/tar"
"compress/gzip"
"fmt"
"io"
"log"
"os"
)
func ExtractTarGz(gzipStream io.Reader) {
uncompressedStream, err := gzip.NewReader(gzipStream)
if err != nil {
log.Fatal("ExtractTarGz: NewReader failed")
}
tarReader := tar.NewReader(uncompressedStream)
for true {
header, err := tarReader.Next()
if err == io.EOF {
break
}
if err != nil {
log.Fatalf("ExtractTarGz: Next() failed: %s", err.Error())
}
switch header.Typeflag {
case tar.TypeDir:
if err := os.Mkdir(header.Name, 0755); err != nil {
log.Fatalf("ExtractTarGz: Mkdir() failed: %s", err.Error())
}
case tar.TypeReg:
outFile, err := os.Create(header.Name)
if err != nil {
log.Fatalf("ExtractTarGz: Create() failed: %s", err.Error())
}
if _, err := io.Copy(outFile, tarReader); err != nil {
log.Fatalf("ExtractTarGz: Copy() failed: %s", err.Error())
}
outFile.Close()
default:
log.Fatalf(
"ExtractTarGz: uknown type: %s in %s",
header.Typeflag,
header.Name)
}
}
}
func main() {
r, err := os.Open("./file.tar.gz")
if err != nil {
fmt.Println("error")
}
ExtractTarGz(r)
}