C#

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.

C#

bool 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.

Chilkat.Gzip gzip = new Chilkat.Gzip();

//  Set custom Gzip properties:
gzip.Comment = "Example Gzip file created with Chilkat";
gzip.Filename = "custom_name.txt";
gzip.CompressionLevel = 9;
gzip.LastModStr = "Wed, 1 Apr 2025 12:45:26 -0500";

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

//  Compress the file:
success = gzip.CompressFile(inputFile,outputFile);
if (success == false) {
    Debug.WriteLine(gzip.LastErrorText);
    return;
}

Debug.WriteLine("Compression successful.");
Debug.WriteLine("Gzip file created: " + outputFile);