Visual FoxPro

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.

Visual FoxPro

LOCAL lnSuccess
LOCAL loGzip
LOCAL loDt
LOCAL lcInputStr

lnSuccess = 0

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

loGzip = CreateObject('Chilkat.Gzip')
loDt = CreateObject('Chilkat.CkDateTime')

* Set the date/time using a timestamp format (ISO 8601 style):
loDt.SetFromTimestamp("2025-11-15T12:45:26-05:00")

* Apply the date/time to the Gzip object:
lnSuccess = loGzip.SetDt(loDt)
IF (lnSuccess = 0) THEN
    ? loGzip.LastErrorText
    RELEASE loGzip
    RELEASE loDt
    CANCEL
ENDIF

* Compress a string so the custom date/time is embedded in the .gz:
lcInputStr = "Example text for Gzip compression."
lnSuccess = loGzip.CompressStringToFile(lcInputStr,"utf-8","output.gz")
IF (lnSuccess = 0) THEN
    ? loGzip.LastErrorText
    RELEASE loGzip
    RELEASE loDt
    CANCEL
ENDIF

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

RELEASE loGzip
RELEASE loDt