Powershell, look through all drives - powershell

Question

I'm new to Powershell and I've tried finding a solution to my problem online but I can't seem to find one. Basically I need to write something that will let powershell look through all drives and directories to find the following:
total number of files (exclude folders), largest file size, average file size, total file size
Here's what I've written so far:
$source = "get-psdrive"
#attempt at looking through all drives/directories which didn't work
foreach($a in $source) {
#counts files in given directory
Get-ChildItem -Recurse -File -ErrorAction SilentlyContinue -Force |
Measure-Object |
ForEach-Object { $_.Count }
#select largest file in given directory
Get-ChildItem -Recurse -File -ErrorAction SilentlyContinue -Force |
Sort-Object Length -Descending |
Select-Object -First 1
#get average file size in a given directory
Get-ChildItem -Recurse -File -ErrorAction SilentlyContinue -Force |
Measure-Object -Property Length -Average
#sum of file sizes in given directory
(Get-ChildItem -Recurse -File -ErrorAction SilentlyContinue -Force |
Measure-Object -Sum Length).Sum
}
The issue is that it only looks in the C drive. I don't know if there's a way to look through my computer instead of specific drives but I couldn't seem to find a way. Any help is appreciated.

Answer 1

With "..." you define a string, so in your example you try to loop over a string.
Try it like this:
$Drives = Get-PSDrive -PSProvider 'FileSystem'
foreach($Drive in $drives) {
#counts files in given directory
Get-ChildItem -Path $Drive.Root -Recurse -File -ErrorAction SilentlyContinue -Force |
Measure-Object |
ForEach-Object { $_.Count }
#select largest file in given directory
Get-ChildItem -Path $Drive.Root -Recurse -File -ErrorAction SilentlyContinue -Force |
Sort-Object Length -Descending |
Select-Object -First 1
#get average file size in a given directory
Get-ChildItem -Path $Drive.Root -Recurse -File -ErrorAction SilentlyContinue -Force |
Measure-Object -Property Length -Average
#sum of file sizes in given directory
(Get-ChildItem -Path $Drive.Root -Recurse -File -ErrorAction SilentlyContinue -Force |
Measure-Object -Sum Length).Sum
}
Note! I didn't chang your Get-ChildItem code (except the path where it will search). I only wrote the foreach loop.

Answer 2

Could make it a bit faster by feeding the results into a variable, instead of running GCI it 4 times each loop. Something like this:
#specify preferred measures
$average_size = "MB"
$individual_size = "GB"
$total_size = "TB"
Get-PSDrive -PSProvider FileSystem |ForEach-Object {
"`n$($_.Root)" |Write-Host -ForegroundColor Cyan
$details=$null
$details = Get-ChildItem -Path $_.Root -Recurse -File -ErrorAction SilentlyContinue -Force
"`nFile Count: $('{0:N0}' -f $details.count)"
"Average size: "+"$([math]::round(($details |
Measure-Object -Property Length -Average |select -Property average).average /"1$($average_size)", 2))"+" $($average_size)"
"Total size: "+"$([math]::round(($details |
Measure-Object -Property Length -sum |select -Property sum).sum /"1$($total_size)", 2))"+" $($total_size)"
$details |
Sort-Object Length -Descending |
Select-Object -First 5 -Property #{L='Path';E ={$_.fullname}},#{L="Size $($individual_size)";E={[math]::round(($_.length) /"1$($individual_size)", 3)}} |ft
}
Couldn't stretch it to assign sizes dynamically, but where do you draw the line...