Renaming a Folder and create a new folder in PowerShell

Question

My folder structure: C:\example\latest. I want to check if the subfolder latest already exists or not. If it does, I want to rename it as latest_MMddyyyy and then create a new folder called latest. If it does not have latest already, then simple create the folder.

This is what I have:

param (
    $localPath = "c:\example\latest\"                                                       #"
)

        #Creating a new directory if does not exist
        $newpath = $localPath+"_"+((Get-Date).AddDays(-1).ToString('MM-dd-yyyy'))
        If (test-path $localPath){
            Rename-Item -path $localpath -newName $newpath
        }
        New-Item -ItemType -type Directory -Force -Path $localPath

It is doing two things:

1. Rename my latest folder as _MM-dd-yyyy but I want it to rename as "latest_MM-dd-yyyy"
2. Throw an error: Missing an argument for parameter 'ItemType'. Specify a parameter of type 'System.String' and try again.

what am I doing wrong?

Answer 1

Throws an error: Missing an argument for parameter 'ItemType'. Specify a parameter of type 'System.String' and try again.

As Deadly-Bagel's helpful answer points out, you're missing an argument to -ItemType and instead follow it with another parameter, -Type, which, in fact, is an alias for -ItemType - so removing either -ItemType or -Type will work.

^{To find a parameter's aliases, use something like (Get-Command New-Item).Parameters['ItemType'].Aliases}

Renames my latest folder to _MM-dd-yyyy, but I want latest_MM-dd-yyyy.

• You append the date string directly to $localPath, which has a trailing \, so $newPath looks something like 'c:\example\latest\_02-08-2017', which is not the intent.

• Ensuring that $localPath has no trailing \ fixes the problem, but do note that Rename-Item generally only accepts a file/directory name as a -NewName argument, not a full path; you can only get away with a full path if its parent path is the same as the input item's - in other words, you can only specify a path if it wouldn't result in a different location for the renamed item (you'd need the Move-Item cmdlet to achieve that).

  • Split-Path -Leaf $localPath offers a convenient way of extracting the last path component, whether or not the input path has a trailing \.
    In this case: latest

  • Alternatively, $localPath -replace '\\$' would always return a path without a trailing \.
    In this case: c:\example\latest

If we put it all together:

param (
  $localPath = "c:\example\latest\"         #"# generally, consider NOT using a trailing \
)

# Rename preexisting directory, if present.
if (Test-Path $localPath) {
 # Determine the new name: the name of the input dir followed by "_" and a date string.
 # Note the use of a single interpolated string ("...") with 2 embedded subexpressions, 
 # $(...)
 $newName="$(Split-Path -Leaf $localPath)_$((Get-Date).AddDays(-1).ToString('MM-dd-yyyy'))"
 Rename-Item -Path $localPath -newName $newName
}

# Recreate the directory ($null = ... suppresses the output).
$null = New-Item -ItemType Directory -Force -Path $localPath

Note that if you run this script more than once on the same day, you'll get an error on renaming (which could easily be handled).

Answer 2

try this

$localPath = "c:\temp\example\latest"

#remove last backslash
$localPath= [System.IO.Path]::GetDirectoryName("$localPath\")                               #"

#create new path name with timestamp
$newpath ="{0}_{1:MM-dd-yyyy}" -f $localPath, (Get-Date).AddDays(-1)

#rename old dir if exist and recreate localpath
Rename-Item -path $localpath -newName $newpath -ErrorAction SilentlyContinue
New-Item -ItemType Directory -Force -Path $localPath