grep in Powershell

Question

What is the mos easy/comfortable way to use Powershells built-in functions to emulate grep like behaviour?

In scripts I use something like this

dir "*.filter" | foreach-object{
    $actfile = $_
    $readerrorfile = [System.IO.Path]::GetTempFileName()
    $found = $false
    $content = Get-Content $actfile 2> $readerrorfile
    $readerror = Get-Content $readerrorfile
    if($readerror -match "Error"){
        echo "Error while reading from file $actfile"
        echo $readerror
        del $readerrorfile
        Write-Host "stopping execution"
        exit
    }else{
        del $readerrorfile
        if($content -match "keyword|regex"){
            echo "found in $actfile"
            $found = true;
        }
    }
}

I fairly sure there is an easier/shorter version for that, maybe a one-liner. So, what is the best way to it the grep way?

Answer 1

I normally do something like:

dir *.txt | select-string "keyword|regex"

For a matching file, this shows me the name of the file, the line number and the contents of the line. This is also pipeline-friendly. I suggest that you have a look at Select-string by using:

help Select-String -Detailed

Answer 2

I find this to be a better alternative than piping dir:

findstr "keyword|regex" *.txt

This doesn't have that wrapping problem.