Question

I’m a beginner in powershell and know C# pretty well. I have this command http://www.f2ko.de/programs.php?lang=en&pid=cmd that downloads stuff. I’m writing this script to download all the sgf go games from this url http://www.gogameworld.com/gophp/pg_samplegames.php, and was trying to write a powershell script to do it for me. So I wrote a script:

    Get-Content test.txt|
    ForEach-Object
    {
        if($_ -eq "=`"javascript:viewdemogame(`'*.sgf`')`" tit")
        {
            $filename = $_ -replace '=`"javascript:viewdemogame(`''
            $filename = $filename -replace '`')`" tit'
            &"(Path)/download.exe"         ("http://www.gogameworld.com/webclient/qipu/" + $filename)
        }
    }

However, when I run the script, I keep getting this error:

    Unexpected token '`'' in expression or statement.
    At (PATH)\test.ps1:7 char:37
    +       $filename = $filename -replace '`' <<<< )'
        + CategoryInfo          : ParserError: (`':String) [], ParentContainsErrorRecordException
        + FullyQualifiedErrorId : UnexpectedToken

I’ve looked at the script lots of times and still can’t figure out whats wrong. Thanks.

Answer 1

Try this, read the content of the file as one string and then use the Regex.Matches to get all occurrences of the text contained in the parenthesis:

$content = Get-Content test.txt | Out-String
$baseUrl = 'http://www.gogameworld.com/webclient/qipu/'

[regex]::matches($content,"javascript:viewdemogame\('([^\']+)'\)") | Foreach-Object{
    $url = '{0}{1}' -f $baseUrl,$_.Groups[1].Value
     & "(Path)/download.exe" $url 
}

here’s an explanation of the regex pattern (created with RegexBuddy):

javascript:viewdemogame\('([^\']+)'\)

Match the characters “javascript:viewdemogame” literally «javascript:viewdemogame»
Match the character “(” literally «\(»
Match the character “'” literally «'»
Match the regular expression below and capture its match into backreference number 1 «([^\']+)»
   Match any character that is NOT a ' character «[^\']+»
      Between one and unlimited times, as many times as possible, giving back as needed (greedy) «+»
Match the character “'” literally «'»
Match the character “)” literally «\)»
Match the character “"” literally «"»

‘{0}{1}’ is used with the -f operator to create a string. {0} maps to the first value on the right hand side of the operator (e.g $baseUrl) and {1} is mapped to the second value. Under the hood, PowerShell is suing the .NET String.Format method. You can read more about it here: http://devcentral.f5.com/weblogs/Joe/archive/2008/12/19/powershell-abcs—f-is-for-format-operator.aspx