Why is PS Get-ChildItem so difficult

Question

I did a ton of reading and searching about a way to have Get-ChildItem return a dir listing in wide format, in alphabetical order, with the number of files and directories in the current directory. Here is a image of what I ended up with, but not using GCI.

I ended up writing a small PS file.

$bArgs = "--%/c"
$cArgs = "Dir /n/w"
& cmd.exe -ArgumentList $bArgs $cArgs

As you can see I ended up using the old cmd.exe and passing the variables I wanted. I made an alias in my PS $Profile to call this script. Can this not be accomplished in PS v5.1? Thanks for any help or advice for an old noob.

Answer 1

PowerShell's for-display formatting differs from cmd.exe's, so if you want the formatting of the latter's internal dir command, you'll indeed have to call it via cmd /c, via a function you can place in your $PROFILE file (note that aliases in PowerShell are merely alternative names and can therefore not include baked-in arguments):

function lss { cmd /c dir /n /w /c $args }

Note that you lose a key benefit of PowerShell: the ability to process rich objects:

• PowerShell-native commands output rich objects that enable robust programmatic processing; e.g., Get-ChildItem outputs System.IO.FileInfo and System.IO.DirectoryInfo instances; the aspect of for-display formatting is decoupled from the data output, and for-display formatting only kicks in when printing to the display (host), or when explicitly requested.

  • For instance, (Get-ChildItem -File).Name returns an array of all file names in the current directory.

• By contrast, PowerShell can only use text to communicate with external programs, which makes processing cumbersome and brittle, if information must be extracted via text parsing.

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As Pierre-Alain Vigeant notes, the following PowerShell command gives you at least similar output formatting as your dir command, though it lacks the combined-size and bytes-free summary at the bottom:

Get-ChildItem | Format-Wide -AutoSize

To wrap that up in a function, use:

function lss { Get-ChildItem @args | Format-Wide -Autosize }

Note, however, that - due to use of a Format-* cmdlet, all of which output objects that are formatting instructions rather than data - this function's output is also not suited to further programmatic processing.

A proper solution would require you to author custom formatting data and associate them with the System.IO.FileInfo and System.IO.DirectoryInfo types, which is nontrivial however.

See the conceptual about_Format.ps1xml help topic, Export-FormatData, Update-FormatData, and this answer for a simple example.