Go

Compress a File to Gzip with Custom Metadata

See more Gzip Examples

This example demonstrates how to use the CompressFile method to create a Gzip (.gz) file while customizing the metadata embedded in the Gzip header.

Before compression, several properties are set:

• Comment: Adds a descriptive comment to the Gzip file.
• Filename: Specifies the filename to embed in the Gzip data, which may be used by extraction tools as the default output name.
• CompressionLevel: Controls the tradeoff between compression ratio and speed (set to maximum in this example).
• LastModStr: Sets the last-modified timestamp using an RFC 822 formatted date string.

After setting these properties, the input file is compressed and written to a .gz file. This approach allows you to embed meaningful metadata along with the compressed data.

Go

    success := false

    // This example demonstrates how to compress a file to Gzip format
    // while setting custom metadata such as comment, filename,
    // compression level, and last-modified date.

    gzip := chilkat.NewGzip()

    // Set custom Gzip properties:
    gzip.SetComment("Example Gzip file created with Chilkat")
    gzip.SetFilename("custom_name.txt")
    gzip.SetCompressionLevel(9)
    gzip.SetLastModStr("Wed, 1 Apr 2025 12:45:26 -0500")

    // The file to be compressed:
    inputFile := "example.txt"
    outputFile := "example.txt.gz"

    // Compress the file:
    success = gzip.CompressFile(inputFile,outputFile)
    if success == false {
        fmt.Println(gzip.LastErrorText())
        gzip.DisposeGzip()
        return
    }

    fmt.Println("Compression successful.")
    fmt.Println("Gzip file created: ", outputFile)

    gzip.DisposeGzip()