This could be useful for tracking any temporary files such as web metering to understand what files are being generated, but could be useful for any general troubleshooting.

##
#Description:
#Log the files written in a folder path. 
# 
# Version: 1.1
# Updated: 20231121
# Author: Julian Dalley
# Change: Added limit to log file size, and day roll for log, now logs deleted files.
###

###<<<<RUN IN POWERSHELL ISE AS ADMINISTRATOR>>>>###

# Define the folder path to monitor
$folderToMonitor = "C:\Temp"

# Define the log file path and size limit (in bytes)
$logPath = "C:\File\Logfolder"
$logSizeLimit = 1048576 # 1 MB (adjust as needed)

# Create a FileSystemWatcher to monitor the folder and subfolders
$watcher = New-Object System.IO.FileSystemWatcher
$watcher.Path = $folderToMonitor
$watcher.IncludeSubdirectories = $true
$watcher.EnableRaisingEvents = $true

# Function to check and rotate log file if size limit is reached or new day begins
function RotateLogFile {
    $currentDate = Get-Date -Format "yyyy-MM-dd"
    $logFileName = $currentDate + "-FileLog.txt"
    $logFilePath = Join-Path -Path $logPath -ChildPath $logFileName
    
    if ((Test-Path -Path $logFilePath) -and ((Get-Item $logFilePath).length -ge $logSizeLimit)) {
        $newLogFileName = (Get-Date -Format "yyyy-MM-dd_HH-mm-ss") + "-FileLog.txt"
        $newLogFilePath = Join-Path -Path $logPath -ChildPath $newLogFileName
        Rename-Item -Path $logFilePath -NewName $newLogFileName
        Write-Host "Log file rotated. New log file created: $newLogFilePath"
    }
    
    # Check if a new day has started
    $currentDay = Get-Date -Format "yyyy-MM-dd"
    if ($currentDay -ne $global:previousDay) {
        $global:previousDay = $currentDay
        $newLogFileName = $currentDay + "-FileLog.txt"
        $newLogFilePath = Join-Path -Path $logPath -ChildPath $newLogFileName
        if (!(Test-Path -Path $newLogFilePath)) {
            New-Item -Path $newLogFilePath -ItemType File -Force
            Write-Host "New day started. Created new log file: $newLogFilePath"
        }
    }
}

# Function to log output to console and file
function LogOutput {
    param (
        [string]$logEntry
    )

    Write-Host $logEntry
    RotateLogFile

    # Define the log file name with an ISO date
    $logFileName = (Get-Date -Format "yyyy-MM-dd") + "-FileLog.txt"
    $logFilePath = Join-Path -Path $logPath -ChildPath $logFileName

    # Append the log entry to the log file
    Add-Content -Path $logFilePath -Value $logEntry
}

# Define the event to trigger when a new file is created
$createdEventAction = {
    $file = $Event.SourceEventArgs.Name
    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    $logEntry = "$timestamp - New file created: $file"

    # Log output for created file
    LogOutput -logEntry $logEntry
}

# Define the event to trigger when a file is deleted
$deletedEventAction = {
    $file = $Event.SourceEventArgs.Name
    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
    $logEntry = "$timestamp - File deleted: $file"

    # Log output for deleted file
    LogOutput -logEntry $logEntry
}

# Register the events for created and deleted files
Register-ObjectEvent -InputObject $watcher -EventName "Created" -Action $createdEventAction
Register-ObjectEvent -InputObject $watcher -EventName "Deleted" -Action $deletedEventAction

# Start an infinite loop to keep the script running
Write-Host "Monitoring folder: $folderToMonitor"
Write-Host "Logging to: $logPath"
Write-Host "Press Ctrl+C to exit."

# Initialize previous day variable
$global:previousDay = Get-Date -Format "yyyy-MM-dd"

while ($true) {
    Start-Sleep -Seconds 1
}