Powershell colored directory listing is incorrect with format-wide

Question

I got this colored dir script from http://tasteofpowershell.blogspot.com/2009/02/get-childitem-dir-results-color-coded.html:

function ls {
  $regex_opts = ([System.Text.RegularExpressions.RegexOptions]::IgnoreCase -bor [System.Text.RegularExpressions.RegexOptions]::Compiled)

  $fore = $Host.UI.RawUI.ForegroundColor
  $compressed = New-Object System.Text.RegularExpressions.Regex('\.(zip|tar|gz|rar)$', $regex_opts)
  $executable = New-Object System.Text.RegularExpressions.Regex('\.(exe|bat|cmd|ps1|psm1|vbs|rb|reg|dll|o|lib)$', $regex_opts)
  $executable = New-Object System.Text.RegularExpressions.Regex('\.(exe|bat|cmd|ps1|psm1|vbs|rb|reg|dll|o|lib)$', $regex_opts)
  $source = New-Object System.Text.RegularExpressions.Regex('\.(py|pl|cs|rb|h|cpp)$', $regex_opts)
  $text = New-Object System.Text.RegularExpressions.Regex('\.(txt|cfg|conf|ini|csv|log|xml)$', $regex_opts)

  Invoke-Expression ("Get-ChildItem $args") |
    %{
      if ($_.GetType().Name -eq 'DirectoryInfo') {
        $Host.UI.RawUI.ForegroundColor = 'DarkCyan'
        $_
        $Host.UI.RawUI.ForegroundColor = $fore
      } elseif ($compressed.IsMatch($_.Name)) {
        $Host.UI.RawUI.ForegroundColor = 'Yellow'
        $_
        $Host.UI.RawUI.ForegroundColor = $fore
      } elseif ($executable.IsMatch($_.Name)) {
        $Host.UI.RawUI.ForegroundColor = 'Red'
        $_
        $Host.UI.RawUI.ForegroundColor = $fore
      } elseif ($text.IsMatch($_.Name)) {
        $Host.UI.RawUI.ForegroundColor = 'Green'
        $_
        $Host.UI.RawUI.ForegroundColor = $fore
      } elseif ($source.IsMatch($_.Name)) {
        $Host.UI.RawUI.ForegroundColor = 'Cyan'
        $_
        $Host.UI.RawUI.ForegroundColor = $fore
      } else {
        $_
      }
    }
}

It works great, but I most of the time I want only the file names, in wide format. So after the invoke-expression call, I added

  Invoke-Expression ("Get-ChildItem $args") |
    %{
      if ($_.GetType().Name -eq 'DirectoryInfo') {
  :
  :
  :
        $_
      }
    } | format-wide -property Name
}

Now I have a bug. Only the colour of the second column is correct; the first item in each column takes the colour of the item in the second column. For example, if I have

> ls

Directory     Program.exe

Then both Directory and Program.exe will be red, even though Directory is supposed to be DarkCyan. How can I correct this?

Answer 1

Rather than twiddling the foreground/background colors of the host in between displaying text to the screen, why don't you use Write-Host which gives you a bit more control over the displayed text (you can control when newlines are output) e.g.:

$_ | Out-String -stream | Write-Host -Fore Red

And for the wide listing use, you will need to handle the column formatting yourself unless you want to update the format data XML for the DirectoryInfo/FileInfo types. If you don't want to do that, then you can write out each name - padded out appropriately - with the desired color. On the last column, set the -NoNewLine param to $false:

$width =  $host.UI.RawUI.WindowSize.Width
$cols = 3   
ls | % {$i=0; $pad = [int]($width/$cols) - 1} `
       {$nnl = ++$i % $cols -ne 0; `
        Write-Host ("{0,-$pad}" -f $_) -Fore Green -NoNewLine:$nnl}