file_one_liners.ps1

# Count files in current dir and all subdirectories
(Get-ChildItem *.jpg -Recurse -File | Measure-Object).Count

# Measure size of files in current directory and all subdirectories (in Gb)
(Get-ChildItem *.jpg -Recurse -File | Measure-Object -Property Length -Sum).Sum / 1Gb

# Get 100 random jpg files and exclude FOLDER (you have to provide CountOfFiles)
Get-ChildItem -Exclude FOLDER | Get-ChildItem -Recurse -Filter *.jpg -File | Get-Random -Count CountOfFiles | Select-Object -First 100

# Same as above but copies selected files to DESTINATION_FOLDER
Get-ChildItem -Exclude FOLDER | Get-ChildItem -Recurse -Filter *.jpg -File | Get-Random -Count CountOfFiles | Select-Object -First 100 | Copy-Item -Destination DESTINATION_FOLDER