Make an image downloader [PowerShell]

PowerShell - a tool bundled on Windows has rich functions to extract elements in HTML pages easily.
I made a script to download images in a HTML page.

Code

Param( $url )

#Get the web page from the URL in the argument
$page = Invoke-WebRequest $url

#Download images
foreach($linkElement in $page.Links.href) {

    # Set the file name as the last string of the path
    $fileName = Split-Path $linkElement -Leaf

    # Get extension from the file name
    $extension = [IO.Path]::GetExtension($filename)

    # In case of the extension is ".jpg" or ".png"
    if ( $extension -eq ".jpg" -or $extension -eq ".png") {

        # Get the file of the link and save it
        Invoke-WebRequest $linkElement -OutFile $fileName
    }
}

Param( $url )

#Get the web page from the URL in the argument

$page = Invoke-WebRequest $url

#Download images

foreach($linkElement in $page.Links.href) {

# Set the file name as the last string of the path

$fileName = Split-Path $linkElement -Leaf

# Get extension from the file name

$extension = [IO.Path]::GetExtension($filename)

# In case of the extension is ".jpg" or ".png"

if ( $extension -eq ".jpg" -or $extension -eq ".png") {

# Get the file of the link and save it

Invoke-WebRequest $linkElement -OutFile $fileName

}

Get arguments on PowerShell script

In order to get arguments on PowerShell, "Param(arg1, arg2, ...)" is used.
At this time, The script receives 1 URL.

Param( $url )

Get a HTML page

“Invoke-WebRequest” is used to get HTML page by a PowerShell script.
An object of the page is set to $page.

$page = Invoke-WebRequest $url

Check links on the page

The page got by the script has links. The script need to check if the each link is for an image or not.
You can check each variable by foreach($variable in $array).

foreach($linkElement in $page.Links.href)

Escape from the loop after checking all the links.

Check file name from the link

In order to copy file name from the link, the script has to copy the last element of the path string.
“Split-Path” is used to do it. “Split-Path” has a option to get the last element(Leaf).

$fileName = Split-Path $linkElement -Leaf

More information is available on MSDN.

Split-Path
https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.management/split-path?view=powershell-5.1