Rename files to lowercase in Powershell

Question

I am trying to rename a bunch of files recursively using Powershell 2.0. The directory structure looks like this:

Leaflets
+ HTML
  - File1
  - File2
  ...
+ HTMLICONS
  + IMAGES
    - Image1
    - Image2
  - File1
  - File2
  ...
+ RTF
  - File1
  - File2
  ...
+ SGML
  - File1
  - File2
  ...

I am using the following command:

get-childitem Leaflets -recurse | rename -newname { $_.name.ToLower() }

and it seems to rename the files, but complains about the subdirectories:

Rename-Item : Source and destination path must be different.

I reload the data monthly using robocopy, but the directories do not change, so I can rename them by hand. Is there any way to get get-children to skip the subdirectories (like find Leaflets -type f ...)?

Thanks.

UPDATE: It appears that the problem is with files that are already all lower case. I tried changing the command to:

get-childitem Leaflets -recurse | if ($_.name -ne $_name.ToLower()) rename -newname { $_.name.ToLower() }

but now Powershell complains that if is not a cmdlet, function, etc. Can I pipe the output of get-childitem to an if statement?

UPDATE 2: This works:

$files=get-childitem Leaflets -recurse
foreach ($file in $files)
{
    if ($file.name -ne $file.name.ToLower())
    {
        rename -newname { $_.name.ToLower() }
    }
}

Herold

In PowerShell 7 at least, Rename-Item doesn't error out if the new name is the same as the old name. I'm not sure which version this behavior changed in though. But your first attempt piping gci to rename-item works now. – Cytogenetics

Answer 1

Even though you have already posted your own answer, here is a variation:

dir Leaflets -r | % { if ($_.Name -cne $_.Name.ToLower()) { ren $_.FullName $_.Name.ToLower() } }

Some points:

• dir is an alias for Get-ChildItem (and -r is short for -Recurse).
• % is an alias for ForEach-Object.
• -cne is a case-sensitive comparison. -ne ignores case differences.
• $_ is how you reference the current item in the ForEach-Object loop.
• ren is an alias for Rename-Item.
• FullName is probably preferred as it ensures you will be touching the right file.

If you wanted to excludes directories from being renamed, you could include something like:

if ((! $_.IsPsContainer) -and $_.Name -cne $_.Name.ToLower()) { ... }

Hopefully this is helpful in continuing to learn and explore PowerShell.

Allerus

Worth mentioning that this works for renaming files but not directories. For directories, you'll need to do 2 rename operations. See here for an example. – Aorta

Answer 2

Keep in mind that you can pipe directly to Rename-Item and use Scriptblocks with the -NewName parameter (because it also accepts pipeline input) to simplify this task:

Get-ChildItem -r | Where {!$_.PSIsContainer} | 
                   Rename-Item -NewName {$_.FullName.ToLower()}

and with aliases:

gci -r | ?{!$_.PSIsContainer} | rni -New {$_.FullName.ToLower()}

Gev

Thanks. And to change file names we can use this : gci . -recurse -force | ?{!$_.PSIsContainer} | rni -New {$_.Name.replace("aaa","bbb")} – Indentation

Answer 3

There are many issues with the previous given answers due to the nature of how Rename-Item, Piping, Looping and the Windows Filesystem works. Unfortunatly the the most simple (not using aliases for readability here) solution I found to rename all files and folders inside of a given folder to lower-case is this one:

Get-ChildItem -Path "/Path/To/You/Folder" -Recurse | Where{ $_.Name -cne $_.Name.ToLower() } | ForEach-Object { $tn="$($_.Name)-temp"; $tfn="$($_.FullName)-temp"; $nn=$_.Name.ToLower(); Rename-Item -Path $_.FullName -NewName $tn; Rename-Item -Path $tfn -NewName $nn -Force; Write-Host "New Name: $($nn)";}

Taft

I used this to rename a few million files - one catch is it doesn't handle files with a bracket eg: '[' or ']' . I think something here has a solution. I didn't attempt to fix because I have a post work around and this took care of most issues. – Skiles

You might also need the folders lower cased - something like this can be run from the root of where you are working: ``` #Get the directories / sub directories and rename to lowercase Get-ChildItem -recurse| ?{ $_.PSIsContainer -And $_.Name -CMatch "[A-Z]" } | %{ $NName = $_.Name.ToLower() #Set temporary name to enable rename to the same name; Windows is not case sensitive $TempItem = Rename-Item -Path $_.FullName -NewName "x$NName" -PassThru Rename-Item -Path $TempItem.FullName -NewName $NName } ``` – Skiles

Should use Rename-Item -LiteralPath instead of -Path as some file types are not supported (like brackets otherwise). – Skiles

Answer 4

You need to temporarily rename them to something else then name them back all lower case.

$items = get-childitem -Directory -Recurse

foreach ($item in $items)
{

   if ($item.name -eq $item.name.ToLower())
   {    

       $temp = $item.FullName.ToLower() + "_"
       $name = $item.FullName.ToLower()
       ren $name $temp

       ren $temp $name
   }

Wriggler

Answer 5

slight tweak on this, if you only want to update the names of files of a particular type try this:

get-childitem *.jpg | foreach { if ($_.Name -cne $_.Name.ToLower()) { ren $_.FullName $_.Name.ToLower() } }

this will only lowercase the jpg files within your folder and ignore the rest

Fraudulent

Answer 6

for everyone who is following this thread; the following line can also be used to lower both files and directories.

Get-ChildItem -r  | Rename-Item -NewName { $_.Name.ToLower().Insert(0,'_') } -PassThru |  Rename-Item -NewName { $_.Name.Substring(1) }

Main post: https://mcmap.net/q/454413/-how-can-i-modify-this-powershell-script-to-include-changing-directory-names-to-lower

Urticaceous

Answer 7

It's more idomatic in PowerShell to use where instead of if in a pipeline:

gci -Recurse Leaflets | 
    ? { $_.Name -ne $_.Name.ToLower()) } | 
    % { ren -NewName $_.Name.ToLower() }

Guardado

Answer 8

A small but important correction to the answer from Jay Bazuzi. The -cne (case sensitive not equal) operator must be used if the where-part should return anything.

Additionally I found that the Path parameter needed to be present. This version worked in my setup:

gci -Recurse | 
    ? { $_.Name -cne $_.Name.ToLower() } | 
    % { ren $_.Name -NewName $_.Name.Tolower()  }

Antiphonary

did you test your code on an uppercase folder? The actual issue is that rename-item throws an error because it considers uppercase==lower internally. – Mightily

Answer 9

Modified to work with [] brackets in the name or other unsupported chars and will handle the directories too (or you can leave that out). I pieced this together from various places.

Should be able to put this in a file, then navigate to the target dir and run it from there.

#Get the directories / sub directories and rename to lowercase 
Get-ChildItem -recurse| ?{ $_.PSIsContainer -And $_.Name -CMatch "[A-Z]" } | %{ 
$NName = $_.Name.ToLower() 
#Set temporary name to enable rename to the same name; Windows is not case sensitive 
$TempItem = Rename-Item -LiteralPath $_.FullName -NewName "x$NName" -PassThru Rename-Item -LiteralPath $TempItem.FullName -NewName $NName }

#Now handle all the files
Get-ChildItem -LiteralPath . -Recurse | Where{ $_.Name -cne $_.Name.ToLower() } | ForEach-Object { 
$tn="$($_.Name)-temp"; $tfn="$($_.FullName)-temp"; 
$nn=$_.Name.ToLower(); 
Rename-Item -LiteralPath $_.FullName -NewName $tn; 
Rename-Item -LiteralPath $tfn -NewName $nn -Force; 
Write-Host "New Name: $($nn)";
}

Skiles