PowerBuilder

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.

PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Gzip
string ls_InputFile
string ls_OutputFile

li_Success = 0

// 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.

loo_Gzip = create oleobject
li_rc = loo_Gzip.ConnectToNewObject("Chilkat.Gzip")
if li_rc < 0 then
    destroy loo_Gzip
    MessageBox("Error","Connecting to COM object failed")
    return
end if

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

// The file to be compressed:
ls_InputFile = "example.txt"
ls_OutputFile = "example.txt.gz"

// Compress the file:
li_Success = loo_Gzip.CompressFile(ls_InputFile,ls_OutputFile)
if li_Success = 0 then
    Write-Debug loo_Gzip.LastErrorText
    destroy loo_Gzip
    return
end if

Write-Debug "Compression successful."
Write-Debug "Gzip file created: " + ls_OutputFile


destroy loo_Gzip