Removing parts of filenames in Powershell from a file list - powershell

Question

I have a bunch of directories with files in them and my goal is to loop through a directory structure and write each of the files one by one to a new location.
The files on disk look like this:
- DATAFILE1_DATE_20210101_RUNDATE_20210101.csv
- DATAFILE1_DATE_20210102_RUNDATE_20210102.csv
- DATEFILE2_DATE_20210103_RUNDATE_20210103.json
- DATEFILE2_DATE_20210104_RUNDATE_20210104.json
I'm trying to pass the contents of the directory to a variable $fileSystemItems and then to remove everything after _DATE so that I could build a new directory structure in the target as:
- /target/DATAFILE1/DATAFILE1_DATE_20210101_RUNDATE_20210101.csv
- /target/DATAFILE1/DATAFILE1_DATE_20210102_RUNDATE_20210102.csv
- /target/DATAFILE2/DATEFILE2_DATE_20210103_RUNDATE_20210103.json
- /target/DATAFILE2/DATEFILE2_DATE_20210104_RUNDATE_20210104.json
The PS code I have so far takes the files from a specified directory and outputs them:
$sourcePath = "\\files\data"
$fileSystemItems = Get-ChildItem $sourcePath -Recurse | Where { ! $_.PSIsContainer }
foreach ($file in $fileSystemItems) {
Write-Host "Writing name of the file is $($file.BaseName)"
}
I have tried using the Rename-Item and regex but renaming the files the source is not an option as other programs are accessing the same data, for example:
Get-ChildItem $sourcePath -Recurse | Rename-Item -NewName { $_.Name -replace "^_DATE+","" }
How do I modify the filename in the $file variable in the foreach loop to output both a edited version of the file name (e.g. DATEFILE1) and also the full file name DATAFILE1_DATE_20210101_RUNDATE_20210101.csv ?

Answer 1

Rename-Item is a great tool to begin with! First, let's optimize your code snippet a little bit:
Instead of piping Get-ChildItems output to Where { ! $_.PSIsContainer }, we'll use the -File switch.
Let's also change your regex from ^_DATE+ to _DATE.* and use a pipeline with ForEach-Object:
Get-ChildItem $sourcePath -Recurse -File | ForEach-Object {
Rename-Item -Path $_.Fullname -NewName (($_.Name -replace "_DATE.*","") + $_.Extension)
}
Looking at your destination structure it looks like you might also want to move files to a target directory.