Golang : Compress and decompress file with compress/flate example
A quick and simple tutorial on how to compress a file with Golang's compress/flate
package. Package flate implements the DEFLATE compressed data format, as described in RFC 1951.
To compress a file, pipe and flush the data out with NewWriter()
function :
package main
import (
"compress/flate"
"fmt"
"io"
"os"
)
func main() {
inputFile, err := os.Open("file.txt")
if err != nil {
fmt.Println(err)
os.Exit(1)
}
defer inputFile.Close()
outputFile, err := os.Create("file.txt.compressed")
if err != nil {
fmt.Println(err)
os.Exit(1)
}
defer outputFile.Close()
flateWriter, err := flate.NewWriter(outputFile, flate.BestCompression)
if err != nil {
fmt.Println("NewWriter error ", err)
os.Exit(1)
}
defer flateWriter.Close()
io.Copy(flateWriter, inputFile)
flateWriter.Flush()
}
Sample test data :
>cat file.txt
This is a test file for Golang Compress/Flate
This is a test file for Golang Compress/Flate
This is a test file for Golang Compress/Flate
This is a test file for Golang Compress/Flate
This is a test file for Golang Compress/Flate
This is a test file for Golang Compress/Flate
>cat file.txt.compressed
��,V�D������T���"��ļt��܂���b}��ĒT�Q�#U5����
To decompress the file, read in the compressed data with NewReader()
function before piping out the decompressed data to file
package main
import (
"compress/flate"
"fmt"
"io"
"os"
)
func main() {
inputFile, err := os.Open("file.txt.compressed")
if err != nil {
fmt.Println(err)
os.Exit(1)
}
defer inputFile.Close()
outputFile, err := os.Create("file.txt.decompressed")
if err != nil {
fmt.Println(err)
os.Exit(1)
}
defer outputFile.Close()
flateReader := flate.NewReader(inputFile)
defer flateReader.Close()
io.Copy(outputFile, flateReader)
}
Happy coding!
Reference :
See also : Golang : Gzip file example
By Adam Ng
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