(Ruby) 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.

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require 'chilkat'

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::CkGzip.new()

# Set custom Gzip properties:
gzip.put_Comment("Example Gzip file created with Chilkat")
gzip.put_Filename("custom_name.txt")
gzip.put_CompressionLevel(9)
gzip.put_LastModStr("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)
    print gzip.lastErrorText() + "\n";
    exit
end

print "Compression successful." + "\n";
print "Gzip file created: " + outputFile + "\n";