问题
is there a easy way to unzip file with golang ?
right now my code is:
func Unzip(src, dest string) error {
r, err := zip.OpenReader(src)
if err != nil {
return err
}
defer r.Close()
for _, f := range r.File {
rc, err := f.Open()
if err != nil {
return err
}
defer rc.Close()
path := filepath.Join(dest, f.Name)
if f.FileInfo().IsDir() {
os.MkdirAll(path, f.Mode())
} else {
f, err := os.OpenFile(
path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, f.Mode())
if err != nil {
return err
}
defer f.Close()
_, err = io.Copy(f, rc)
if err != nil {
return err
}
}
}
return nil
}
回答1:
Slight rework of the OP's solution to create the containing directory dest if it doesn't exist, and to wrap the file extraction/writing in a closure to eliminate stacking of defer .Close() calls per @Nick Craig-Wood's comment:
func Unzip(src, dest string) error {
r, err := zip.OpenReader(src)
if err != nil {
return err
}
defer func() {
if err := r.Close(); err != nil {
panic(err)
}
}()
os.MkdirAll(dest, 0755)
// Closure to address file descriptors issue with all the deferred .Close() methods
extractAndWriteFile := func(f *zip.File) error {
rc, err := f.Open()
if err != nil {
return err
}
defer func() {
if err := rc.Close(); err != nil {
panic(err)
}
}()
path := filepath.Join(dest, f.Name)
if f.FileInfo().IsDir() {
os.MkdirAll(path, f.Mode())
} else {
os.MkdirAll(filepath.Dir(path), f.Mode())
f, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, f.Mode())
if err != nil {
return err
}
defer func() {
if err := f.Close(); err != nil {
panic(err)
}
}()
_, err = io.Copy(f, rc)
if err != nil {
return err
}
}
return nil
}
for _, f := range r.File {
err := extractAndWriteFile(f)
if err != nil {
return err
}
}
return nil
}
Note: Updated to include Close() error handling as well (if we're looking for best practices, may as well follow ALL of them).
回答2:
I'm using archive/zip package to read .zip files and copy to the local disk. Below is the source code to unzip .zip files for my own needs.
import (
"archive/zip"
"io"
"log"
"os"
"path/filepath"
"strings"
)
func unzip(src, dest string) error {
r, err := zip.OpenReader(src)
if err != nil {
return err
}
defer r.Close()
for _, f := range r.File {
rc, err := f.Open()
if err != nil {
return err
}
defer rc.Close()
fpath := filepath.Join(dest, f.Name)
if f.FileInfo().IsDir() {
os.MkdirAll(fpath, f.Mode())
} else {
var fdir string
if lastIndex := strings.LastIndex(fpath,string(os.PathSeparator)); lastIndex > -1 {
fdir = fpath[:lastIndex]
}
err = os.MkdirAll(fdir, f.Mode())
if err != nil {
log.Fatal(err)
return err
}
f, err := os.OpenFile(
fpath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, f.Mode())
if err != nil {
return err
}
defer f.Close()
_, err = io.Copy(f, rc)
if err != nil {
return err
}
}
}
return nil
}
回答3:
I would prefer using 7zip with Go, which would give you something like this.
func extractZip() {
fmt.Println("extracting", zip_path)
commandString := fmt.Sprintf(`7za e %s %s`, zip_path, dest_path)
commandSlice := strings.Fields(commandString)
fmt.Println(commandString)
c := exec.Command(commandSlice[0], commandSlice[1:]...)
e := c.Run()
checkError(e)
}
Better example code
However, if using 7zip isn't possible, then try this. Defer a recover to catch the panics. (Example)
func checkError(e error){
if e != nil {
panic(e)
}
}
func cloneZipItem(f *zip.File, dest string){
// Create full directory path
path := filepath.Join(dest, f.Name)
fmt.Println("Creating", path)
err := os.MkdirAll(filepath.Dir(path), os.ModeDir|os.ModePerm)
checkError(err)
// Clone if item is a file
rc, err := f.Open()
checkError(err)
if !f.FileInfo().IsDir() {
// Use os.Create() since Zip don't store file permissions.
fileCopy, err := os.Create(path)
checkError(err)
_, err = io.Copy(fileCopy, rc)
fileCopy.Close()
checkError(err)
}
rc.Close()
}
func Extract(zip_path, dest string) {
r, err := zip.OpenReader(zip_path)
checkError(err)
defer r.Close()
for _, f := range r.File {
cloneZipItem(f, dest)
}
}
回答4:
I have been doing some browsing of google and repeatedly found people saying that there is no library that can handle that. Maybe I missed a custom repository in my search though and someone else will find it for us.
You may be able to make use of io.Copy(src, dest) to ease the process but I haven't tested it at all.
For instance:
os.MkDirAll(dest, r.File.Mode)
d, _ := os.Open(dest)
io.Copy(r.File, d)
Honestly to me your code looks pretty nice and if I were to do an Extract function myself (and the above doesn't work) then I would probably take a page from your book.
回答5:
While working on the query for catching ZipSlip vulnerabilities in Go on LGTM.com (of which I am a developer), I noticed code similar to the accepted answer in several projects, e.g. rclone.
As @woogoo has pointed out, this code is vulnerable to ZipSlip, so I believe the answer should be updated to something like the following (code taken from rclone fix):
func Unzip(src, dest string) error {
dest = filepath.Clean(dest) + string(os.PathSeparator)
r, err := zip.OpenReader(src)
if err != nil {
return err
}
defer func() {
if err := r.Close(); err != nil {
panic(err)
}
}()
os.MkdirAll(dest, 0755)
// Closure to address file descriptors issue with all the deferred .Close() methods
extractAndWriteFile := func(f *zip.File) error {
path := filepath.Join(dest, f.Name)
// Check for ZipSlip: https://snyk.io/research/zip-slip-vulnerability
if !strings.HasPrefix(path, dest) {
return fmt.Errorf("%s: illegal file path", path)
}
rc, err := f.Open()
if err != nil {
return err
}
defer func() {
if err := rc.Close(); err != nil {
panic(err)
}
}()
if f.FileInfo().IsDir() {
os.MkdirAll(path, f.Mode())
} else {
os.MkdirAll(filepath.Dir(path), f.Mode())
f, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, f.Mode())
if err != nil {
return err
}
defer func() {
if err := f.Close(); err != nil {
panic(err)
}
}()
_, err = io.Copy(f, rc)
if err != nil {
return err
}
}
return nil
}
for _, f := range r.File {
err := extractAndWriteFile(f)
if err != nil {
return err
}
}
return nil
}
回答6:
there is Zip Slip Vulnerability in the code of @Astockwell , see: https://snyk.io/research/zip-slip-vulnerability
来源：https://stackoverflow.com/questions/20357223/easy-way-to-unzip-file-with-golang