Zig

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.

Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // 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.

    const gzip = try chilkat.Gzip.init();
    defer gzip.deinit();

    // 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:
    const input_file = "example.txt";
    const output_file = "example.txt.gz";

    // Compress the file:
    gzip.compressFile(input_file, output_file) catch {
        std.debug.print("{s}\n", .{try gzip.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("Compression successful.\n", .{});
    std.debug.print("Gzip file created: {s}\n", .{output_file});
}