(Tcl) Get the Last-Modified Date Before HTTP Download

Demonstrates how to send a HEAD request to get the last-modified date of a file on a web server (without downloading the file).

Chilkat Tcl Extension Downloads Chilkat Tcl Extension Downloads

load ./chilkat.dll

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

set http [new_CkHttp]

# resp is a CkHttpResponse
set resp [CkHttp_GetHead $http "https://www.chilkatsoft.com/hamlet.xml"]
if {[CkHttp_get_LastMethodSuccess $http] == 0} then {
    puts [CkHttp_lastErrorText $http]
    delete_CkHttp $http
    exit
}

# Examine the response header.
puts [CkHttpResponse_header $resp]

# Here is a sample response header:

# 	Content-Length: 279658
# 	Content-Type: text/xml
# 	Last-Modified: Thu, 12 May 2016 15:14:08 GMT
# 	Accept-Ranges: bytes
# 	ETag: "c1cd8bee60acd11:0"
# 	Server: Microsoft-IIS/8.5
# 	X-Powered-By: ASP.NET
# 	X-Powered-By-Plesk: PleskWin
# 	Date: Thu, 25 Jul 2019 16:40:54 GMT

# Get the Last-Modified header.
set lastModStr [CkHttpResponse_getHeaderField $resp "Last-Modified"]
# If the header exists...
if {[CkHttpResponse_get_LastMethodSuccess $resp] == 1} then {
    # Parse the RFC822 format date/time string
    set ckdt [new_CkDateTime]

    CkDateTime_SetFromRfc822 $ckdt $lastModStr

    # If we want to access individual date/time parts (in the local timezone)
    # dt is a CkDtObj
    set dt [CkDateTime_GetDtObj $ckdt 1]
    puts "day/month/year = [CkDtObj_get_Day $dt]/[CkDtObj_get_Month $dt]/[CkDtObj_get_Year $dt]"
    delete_CkDtObj $dt

}

delete_CkHttpResponse $resp


delete_CkHttp $http
delete_CkDateTime $ckdt