How to compress a file to .zip without directory folder in Go - go

Question

There're examples about compressing a file to .zip in Go. However, the file they generate include the directory folder. When I decompress the .zip file, there will be a new folder.
So, how can I compress a file to .zip without getting the directory folder included?
An example:
https://golangcode.com/create-zip-files-in-go/
package main
import (
"archive/zip"
"fmt"
"io"
"os"
)
func main() {
// List of Files to Zip
files := []string{"example.csv", "data.csv"}
output := "done.zip"
if err := ZipFiles(output, files); err != nil {
panic(err)
}
fmt.Println("Zipped File:", output)
}
// ZipFiles compresses one or many files into a single zip archive file.
// Param 1: filename is the output zip file's name.
// Param 2: files is a list of files to add to the zip.
func ZipFiles(filename string, files []string) error {
newZipFile, err := os.Create(filename)
if err != nil {
return err
}
defer newZipFile.Close()
zipWriter := zip.NewWriter(newZipFile)
defer zipWriter.Close()
// Add files to zip
for _, file := range files {
if err = AddFileToZip(zipWriter, file); err != nil {
return err
}
}
return nil
}
func AddFileToZip(zipWriter *zip.Writer, filename string) error {
fileToZip, err := os.Open(filename)
if err != nil {
return err
}
defer fileToZip.Close()
// Get the file information
info, err := fileToZip.Stat()
if err != nil {
return err
}
header, err := zip.FileInfoHeader(info)
if err != nil {
return err
}
// Using FileInfoHeader() above only uses the basename of the file. If we want
// to preserve the folder structure we can overwrite this with the full path.
header.Name = filename
// Change to deflate to gain better compression
// see http://golang.org/pkg/archive/zip/#pkg-constants
header.Method = zip.Deflate
writer, err := zipWriter.CreateHeader(header)
if err != nil {
return err
}
_, err = io.Copy(writer, fileToZip)
return err
}

Answer 1

Just use a base name of the file in the zip header.
header.Name = filepath.Base(filename)
^^^^^^^^^^^^^^
Here is a version that does the same thing
package main
import (
"archive/zip"
"io"
"log"
"os"
"path/filepath"
)
func createFlatZip(w io.Writer, files ...string) error {
z := zip.NewWriter(w)
for _, file := range files {
src, err := os.Open(file)
if err != nil {
return err
}
info, err := src.Stat()
if err != nil {
return err
}
hdr, err := zip.FileInfoHeader(info)
if err != nil {
return err
}
hdr.Name = filepath.Base(file) // Write only the base name in the header
dst, err := z.CreateHeader(hdr)
if err != nil {
return err
}
_, err = io.Copy(dst, src)
if err != nil {
return err
}
src.Close()
}
return z.Close()
}
func main() {
if len(os.Args) < 3 {
log.Fatalf("archive name and at least one file are required")
}
a, err := os.Create(os.Args[1])
if err != nil {
log.Fatal(err)
}
defer a.Close()
err = createFlatZip(a, os.Args[2:]...)
if err != nil {
log.Fatal(err)
}
}
Results:
~/src/gozip
➜ go build
~/src/gozip
➜ mkdir test && echo 1 > test/1.txt # create a test file in a subfolder
~/src/gozip
➜ ./gozip 1.zip test/1.txt
~/src/gozip
➜ unzip -l 1.zip
Archive: 1.zip
Length Date Time Name
--------- ---------- ----- ----
2 08-15-2019 01:29 1.txt
--------- -------
2 1 file