Compressing directory with to Zip file with Golang

Golang version 1.23.6 supporting tar and zip compressing. In this article I will show you how to compress directory with Golang

Creating a output file

First we need to create output file.

filename := "test.zip"
output_file, err := os.Create(filename)
if err != nil {
	panic(err)
}

if you want to compress with tar file, you can replace extension to the .tar

Creating a writer

w := zip.NewWriter(output_file)
defer w.Close()

creating new file under the zip stream

path := "helloworld.txt"
zipFile, err := w.Create(path)
if err != nil {
	panic(err)
}

Writing to the zip stream

myBytes := []byte("hello world !")
zipFile.Write(myBytes)

> unzip -l test.zip  

  Length      Date    Time    Name
---------  ---------- -----   ----
       13  00-00-1980 00:00   helloworld.txt
---------                     -------
       13                     1 file

>  zipinfo test.zip

Archive:  test.zip
Zip file size: 161 bytes, number of entries: 1
-rw----     2.0 fat       13 bl defN 80-000-00 00:00 helloworld.txt
1 file, 13 bytes uncompressed, 19 bytes compressed:  -46.2%

> unzip -p test.zip helloworld.txt 

hello world !%                                   

Writing header metadata

CreateHeader method provides creating new zip file with metadata in stream

zipFile, err := w.CreateHeader(&zip.FileHeader{
	Name:     path,
	Comment:  "Test Comment",
	Modified: time.Now()},
)

> zipinfo test.zip

Archive:  test.zip
Zip file size: 185 bytes, number of entries: 1
-rw----     2.0 fat       13 bX stor 25-Feb-07 14:35 helloworld.txt
1 file, 13 bytes uncompressed, 13 bytes compressed:  0.0%

we can see that file modification date is updated