(PowerShell) 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 .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

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

$http = New-Object Chilkat.Http

$resp = $http.GetHead("https://www.chilkatsoft.com/hamlet.xml")
if ($http.LastMethodSuccess -eq $false) {
    $($http.LastErrorText)
    exit
}

# Examine the response header.
$($resp.Header)

# 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.
$lastModStr = $resp.GetHeaderField("Last-Modified")
# If the header exists...
if ($resp.LastMethodSuccess -eq $true) {
    # Parse the RFC822 format date/time string
    $ckdt = New-Object Chilkat.CkDateTime
    $ckdt.SetFromRfc822($lastModStr)

    # If we want to access individual date/time parts (in the local timezone)
    $dt = $ckdt.GetDtObj($true)
    $("day/month/year = " + $dt.Day + "/" + $dt.Month + "/" + $dt.Year)

}