Search for text inside files

$lookup = '***'
Out-File -FilePath C:\temp\results.txt -InputObject $lookup -Encoding utf8 -Force -Append 
gci -File 'C:\temp\1' -Recurse -Filter '*.*' -Exclude '*.zip'| 
    select -exp FullName | % { 
        $f = gc $_; $l=1
        foreach($r in @($f.Split("`n"))){
            #if ($r.Length -gt 0 -and $r -match $lookup){Write-Host $("File: {0}`tLine: {1}`tString: {2}" -f $_,$l,$r) -b Black -f Green}; $l++ 
            if ($r.Length -gt 0 -and $r -match $lookup){Out-File -FilePath C:\temp\results.txt -InputObject $("[File: {0}][Line: {1}][String: {2}]" -f $_,$l,$r) -Encoding utf8 -Force -Append }; $l++ 
        }
    }