(DataFlex) Set a Custom Last-Modified Date in a Gzip File

See more Gzip Examples

This example demonstrates how to use the SetDt method to specify a custom last-modified date and time that will be embedded in a Gzip file.

A CkDateTime object is first initialized with a specific date/time using an RFC 822 formatted string. This date/time is then applied to the Gzip object using SetDt.

When a compression method is called (such as CompressStringToFile), the specified date/time is included in the Gzip metadata. This allows the resulting .gz file to carry a meaningful timestamp rather than using the current system time.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoGzip
    Variant vDt
    Handle hoDt
    String sInputStr
    String sTemp1

    Move False To iSuccess

    // This example demonstrates how to set a custom last-modified date/time
    // that will be embedded in a Gzip file.

    Get Create (RefClass(cComChilkatGzip)) To hoGzip
    If (Not(IsComObjectCreated(hoGzip))) Begin
        Send CreateComObject of hoGzip
    End
    Get Create (RefClass(cComCkDateTime)) To hoDt
    If (Not(IsComObjectCreated(hoDt))) Begin
        Send CreateComObject of hoDt
    End

    // Set the date/time using a timestamp format (ISO 8601 style):
    Get ComSetFromTimestamp Of hoDt "2025-11-15T12:45:26-05:00" To iSuccess

    // Apply the date/time to the Gzip object:
    Get pvComObject of hoDt to vDt
    Get ComSetDt Of hoGzip vDt To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoGzip To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Compress a string so the custom date/time is embedded in the .gz:
    Move "Example text for Gzip compression." To sInputStr
    Get ComCompressStringToFile Of hoGzip sInputStr "utf-8" "output.gz" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoGzip To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Gzip file created with custom last-modified date."


End_Procedure