zip a folder of files with golang creates a broken zip - go

Question

how do I zip files in a folder with sub-directories correctly.
I have a local folder with following structure:
folder/hello/
folder/hello/world/
folder/hello/world/helloword.txt
folder/index.txt
this is my code:
package main
import (
"archive/zip"
"fmt"
"io"
"os"
"path/filepath"
)
func main() {
files, err := listFiles("./folder")
if err != nil {
panic(err)
}
zipMe(files, "test.zip")
for _, f := range files {
fmt.Println(f)
}
fmt.Println("Done!")
}
func listFiles(root string) ([]string, error) {
var files []string
err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
files = append(files, path)
return nil
})
if err != nil {
return nil, err
}
return files, nil
}
func zipMe(filepaths []string, target string) error {
flags := os.O_WRONLY | os.O_CREATE | os.O_TRUNC
file, err := os.OpenFile(target, flags, 0644)
if err != nil {
return fmt.Errorf("Failed to open zip for writing: %s", err)
}
defer file.Close()
zipw := zip.NewWriter(file)
defer zipw.Close()
for _, filename := range filepaths {
if err := addFileToZip(filename, zipw); err != nil {
return fmt.Errorf("Failed to add file %s to zip: %s", filename, err)
}
}
return nil
}
func addFileToZip(filename string, zipw *zip.Writer) error {
file, err := os.Open(filename)
if err != nil {
return fmt.Errorf("Error opening file %s: %s", filename, err)
}
defer file.Close()
wr, err := zipw.Create(filename)
if err != nil {
return fmt.Errorf("Error adding file; '%s' to zip : %s", filename, err)
}
if _, err := io.Copy(wr, file); err != nil {
return fmt.Errorf("Error writing %s to zip: %s", filename, err)
}
return nil
}
This creates a broken zip which can not be extracted (I am running on mac os but this should not make a difference).
I also tried several other examples from stackoverflow and links found through google, but I do always get a broken zip. I get a zip with 135 bytes when I extract it I get 1 binary file with 0 bytes).
It would be great if someone could help me to find out what I am missing here.
Thx

Answer 1

You need to list and zip the files, not the directories. Simply make this adjustment to ignore directories in your listFiles function.
if !info.IsDir() {
files = append(files, path)
}