Extract text from html with powershell - bad pattern

Question

I want to extract this text

Spectrum Mortis - Bit Meseri - The Incantation (2022)
Hate Legions - Exitus Letalis (Tota Vita Nihil Aliud Quam Ad Mortem Iter Est) (2014)

from this html block

<span id='tid-span-369523'><a id="tid-link-369523" href="http://metalarea.org/forum/index.php?showtopic=369523" title="This topic was started: Sep 16 2022, 04:18:47">Spectrum Mortis - Bit Meseri - The Incantation (2022)</a></span>
<span id='tid-span-221568'><a id="tid-link-221568" href="http://metalarea.org/forum/index.php?showtopic=221568" title="This topic was started: Apr 11 2014, 14:31:18">Hate Legions - Exitus Letalis (Tota Vita Nihil Aliud Quam Ad Mortem Iter Est) (2014)</a></span>

I'm trying to set this code but nothing is written on output2.txt

$html = Get-Content -Path 'C:\temp\html\metalarea2.html' -Raw

$pattern = '<span id="tid-span-\\d+"><a id="tid-link-\\d+" href=".+?" title=".+?">(.+?)</a></span>'

$matches = Select-String -InputObject $html -Pattern $pattern -AllMatches
$result = $matches | % { $_.Matches } | % { $_.Groups[1].Value }
$result | Out-File -FilePath "C:\temp\html\output2.txt"

I don't understand where the problem lies

EDIT: SOLUTIONS

$pattern = '<span id=\x27tid-span-\d+\x27><a id="tid-link-\d+" href=".+?" title=".+?">(.+?)</a></span>'

OR

$pattern = '<a id="tid-link-\d+".+?>(.+?)</a>'

@mklement0 nothing happens if I use $pattern = '<span id="tid-span-\d+"><a id="tid-link-\d+" href=".+?" title=".+?">(.+?)</a></span>' output2.txt is empty — user3520363
– user3520363, Commented Jan 28, 2023 at 2:57
Take a closer look at your html. span id= is followed by a single quoted string instead of a double quoted string. Use either 2 single quotes, or \x27, to catch the single quotes in a single quoted string: $pattern = '<span id=\x27tid-span-\d+\x27><a id="tid-link-\d+" href=".+?" title=".+?">(.+?)</a></span>' — Darin
– Darin, Commented Jan 28, 2023 at 3:18
@Darin ok, thank you I edit pattern in this way $pattern = '<a id="tid-link-\d+".+?>(.+?)</a>' — user3520363
– user3520363, Commented Jan 28, 2023 at 3:20

iRon · Accepted Answer · 2023-01-28 16:41:45Z

It is generally a bad idea to peek and/or poke in structured text using regular expressions. Instead, it is better to use a proper (html) parser to manipulate your data.

To give you an example using the IHTMLDocument2 interface:

$Html = @'
<html>
    <head>
        <title>Title</title>
    </head>
    <body>
        <span id="tid-span-369523"><a id="tid-link-369523" href="http://metalarea.org/forum/index.php?showtopic=369523" title="This topic was started: Sep 16 2022, 04:18:47">Spectrum Mortis - Bit Meseri - The Incantation (2022)</a></span>
        <span id='tid-span-221568'><a id="tid-link-221568" href="http://metalarea.org/forum/index.php?showtopic=221568" title="This topic was started: Apr 11 2014, 14:31:18">Hate Legions - Exitus Letalis (Tota Vita Nihil Aliud Quam Ad Mortem Iter Est) (2014)</a></span>
        <div id="something">Text within div</div>
    </body>
</html>
'@

function ParseHtml($String) {
    $Unicode = [System.Text.Encoding]::Unicode.GetBytes($String)
    $Html = New-Object -Com 'HTMLFile'
    if ($Html.PSObject.Methods.Name -Contains 'IHTMLDocument2_Write') {
        $Html.IHTMLDocument2_Write($Unicode)
    } 
    else {
        $Html.write($Unicode)
    }
    $Html.Close()
    $Html
}

$Document = ParseHtml $Html
$Document.getElementsByTagName('a') |
    Where-Object { $_.id -Like 'tid-link-*' } |
    Foreach-Object { $_.innerText }

Spectrum Mortis - Bit Meseri - The Incantation (2022)
Hate Legions - Exitus Letalis (Tota Vita Nihil Aliud Quam Ad Mortem Iter Est) (2014)

SavindraSingh · Accepted Answer · 2023-01-28 07:02:46Z

You can use below regular expression to capture plain text between HTML tags:

(<[^>]*>)+(?<plaintext>[^<]+)<\/[^>]*>

You can refer to this example from regex101.com: Live sample

Here is a full script example:

$html = @"
<span id="tid-span-369523"><a id="tid-link-369523" href="http://metalarea.org/forum/index.php?showtopic=369523" title="This topic was started: Sep 16 2022, 04:18:47">Spectrum Mortis - Bit Meseri - The Incantation (2022)</a></span>
<span id='tid-span-221568'><a id="tid-link-221568" href="http://metalarea.org/forum/index.php?showtopic=221568" title="This topic was started: Apr 11 2014, 14:31:18">Hate Legions - Exitus Letalis (Tota Vita Nihil Aliud Quam Ad Mortem Iter Est) (2014)</a></span>
<div id="something">Text within div</div>
"@

$pattern = '(<[^>]*>)+(?<plaintext>[^<]+)<\/[^>]*>'
$options = [System.Text.RegularExpressions.RegexOptions]::Multiline

$matches = [regex]::Matches($html, $pattern, $options)

$results = $matches | %{ $_.Groups["plaintext"].Value }

$results

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