Getting rid of unwanted html in file

Question

I have a file that has the following below, I am trying to remove everything from 

<!--<br>
/* Font Definitions */

-->
Only keep this part

Hi I am new to this site I am using powershell I didn't meant to put r there. Basically I am trying to remove html from a file. — Luigi, Aug 14 '14 at 02:59
Don't use a regex. http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags/1732454#1732454 — Aaron Jensen, Aug 25 '14 at 16:21

score 1 · Answer 1 · edited May 23 '17 at 11:49

Don't use a regex. HTML isn't a regular language, so it can't be properly parsed with a regex. It will succeed most of the time, but other times will fail. Spectacularly.

I recommend cracking open the file, and reading it a character at at time, looking for the characters <, !, -, followed by -. Then, continue reading until you find -, -, !, followed by >.

$chars = [IO.File]::ReadAllText( $path ).ToCharArray()
$newFileContent = New-Object 'Text.StringBuilder'
for( $i = 0; $i -lt $chars.Length; ++$i )
{
    if( $inComment )
    {
        if( $chars[$i] -eq '-' -and $chars[$i+1] -eq '-' -and $chars[$i+2] -eq '!' -and $chars[$i+3] -eq '>' )
        {
            $inComment = $false
            $i += 4
        }
        continue
    }

    if( $chars[$i] -eq '<' -and $chars[$i+1] -eq '!' -and $chars[$i+2] -eq '-' -and $chars[$i+3] -eq '-' )
    {
        $inComment = $true
        $i += 4
        continue
    }

    $newFileContent.Append( $chars[$i] )
}
$newFileContent.ToString() | Set-Content -Path $path

score 0 · Answer 2 · answered Aug 14 '14 at 06:58

0

Regular expressions to the rescue again -

@'
<!--<br>
/* Font Definitions */

-->
Only keep this part 
'@ -replace '(?s)<!--(.+?)-->', ''

(?s) makes dot match new lines :)

answered Aug 14 '14 at 06:58

Andy Arismendi

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Getting rid of unwanted html in file

2 Answers2