Powershell to Split huge folder in multiple folders - powershell

Question

I have a folder that contains many huge files. I want to split these files in 3 folders. The requirement is to get the count of files in main folder and then equally split those files in 3 child folders.
Example - Main folder has 100 files. When I run the powershell, 3 child folders should be created with 33, 33 and 34 files respectively.
How can we do this using Powershell?
I've tried the following:
$FileCount = (Get-ChildItem C:\MainFolder).count
Get-ChildItem C:\MainFolder -r | Foreach -Begin {$i = $j = 0} -Process {
if ($i++ % $FileCount -eq 0) {
$dest = "C:\Child$j"
md $dest
$j++
}
Move-Item $_ $dest
}

Answer 1

Here is another solution. This one accounts for the sub folders not existing.
# Number of groups to support
$groupCount = 3
$path = "D:\temp\testing"
$files = Get-ChildItem $path -File
For($fileIndex = 0; $fileIndex -lt $files.Count; $fileIndex++){
$targetIndex = $fileIndex % $groupCount
$targetPath = Join-Path $path $targetIndex
If(!(Test-Path $targetPath -PathType Container)){[void](new-item -Path $path -name $targetIndex -Type Directory)}
$files[$fileIndex] | Move-Item -Destination $targetPath -Force
}
If you need to split up the files into a different number of groups the use $groupCount of higher that 3. Can also work logic with a switch that would change $groupCount to something else if the count was greater that 500 for example.
Loop though the files one by one. Using $fileIndex as a tracker we determine the folder 0,1 or 2 in my case that the file will be put into. Then using that value we check to be sure the target folder exists. Yes, this logic could easily be placed outside the loop but if you have file and folder changes while the script is running you could argue it is more resilient.
Ensure the folder exists, if not make it. Then move that one item. Using the modulus operator, like in the other answers, we don't have to worry about how many files are there. Let PowerShell do the math.

Answer 2

This is super quick and dirty, but it does the job.
#Get the collection of files
$files = get-childitem "c:\MainFolder"
#initialize a counter to 0 or 1 depending on if there is a
#remainder after dividing the number of files by 3.
if($files.count % 3 -eq 0){
$counter = 0
} else {
$counter = 1
}
#Iterate through the files
Foreach($file in $files){
#Determine which subdirectory to put the file in
If($counter -lt $files.count / 3){
$d = "Dir1"
} elseif($counter -ge $files.count / 3 * 2){
$d = "Dir3"
} else {
$d = "Dir2"
}
#Create the subdirectory if it doesn't exist
#You could just create the three subdirectories
#before the loop starts and skip this
if(-Not (test-path c:\Child\$d)){
md c:\Child\$d
}
#Move the file and increment the counter
move-item $file.FullName -Destination c:\Child\$d
$counter ++
}

Answer 3

I think it's possible to do without doing the counting and allocating yourself. This solution:
Lists all the files
Adds a counter property which cycles 0,1,2,0,1,2,0,1,2 to each file
groups them into buckets based on the counter
moves each bucket in one command
There's scope for rewriting it in a lot of ways to make it nicer, but this saves doing the math, handling uneven allocations, iterating over the files and moving them one at a time, would easily adjust to different numbers of groups.
$files = (gci -recurse).FullName
$buckets = $files |% {$_ | Add-Member NoteProperty "B" ($i++ % 3) -PassThru} |group B
$buckets.Name |% {
md "c:\temp$_"
Move-Item $buckets[$_].Group "c:\temp$_"
}