Add Invoke-OldFilePurge script and README documentation for file cleanup utility

AutomationAccount/Invoke-OldFilePurge/README.md

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+# Invoke-OldFilePurge
+
+## Overview
+
+This PowerShell script deletes files older than a specified number of days from a target directory.
+
+It is designed for high-volume deletion of small files — for example Tomcat temp folders, IIS logs, or other directories that accumulate large numbers of files over time. The function:
+
+- Scans a directory (optionally recursively) for files older than a given age
+- Deletes matching files using `[System.IO.File]::Delete()` for speed
+- Reports progress (percentage, rate, deleted/failed counts) via `Write-Progress`
+- Logs every deletion (and failure) to a timestamped log file
+- Supports `-WhatIf` / `-Confirm` via `SupportsShouldProcess`
+
+---
+
+# Prerequisites
+
+## PowerShell
+
+PowerShell 5.1 or later.
+
+---
+
+# Files
+
+## Invoke-OldFilePurge.ps1
+
+Defines the `Invoke-OldFilePurge` function. Dot-source the file or copy the function into your session/module before use.
+
+```powershell
+. .\Invoke-OldFilePurge.ps1
+```
+
+---
+
+# Parameters
+
+| Parameter | Mandatory | Default | Description |
+|-----------|-----------|---------|-------------|
+| `Path` | Yes | — | Target directory to clean up. |
+| `DaysOld` | No | `7` | Files with `LastWriteTime` older than this many days are deleted. Range: 1–3650. |
+| `Recurse` | No | Enabled | If specified, subdirectories are also scanned. |
+| `LogDir` | No | `C:\Temp` | Directory for the log file. Created automatically if it does not exist. |
+| `LogEnabled` | No | `$true` | Enables or disables logging. |
+
+---
+
+# Running the script
+
+Preview what would be deleted without actually deleting anything:
+
+```powershell
+Invoke-OldFilePurge.ps1 -Path "C:\Program Files\Apache Software Foundation\Tomcat 9.0\temp" -WhatIf
+```
+
+Delete files older than 7 days (default):
+
+```powershell
+Invoke-OldFilePurge.ps1 -Path "C:\Program Files\Apache Software Foundation\Tomcat 9.0\temp"
+```
+
+Delete files older than 30 days and write logs to a custom directory:
+
+```powershell
+Invoke-OldFilePurge.ps1 -Path "D:\IIS\Logs" -DaysOld 30 -LogDir "D:\Logs"
+```
+
+Run without logging:
+
+```powershell
+Invoke-OldFilePurge.ps1 -Path "D:\Temp" -LogEnabled $false
+```
+
+---
+
+# Logging
+
+Each execution (when `LogEnabled` is `$true`) creates a log file:
+
+```
+FileCleanup_YYYYMMDD_HHMMSS.log
+```
+
+Example:
+
+```
+2026-07-02 09:12:11  [INFO ]  === Invoke-OldFilePurge started ===
+2026-07-02 09:12:11  [INFO ]  Path      : D:\IIS\Logs
+2026-07-02 09:12:11  [INFO ]  DaysOld   : 30 (cutoff: 2026-06-02 09:12:11)
+2026-07-02 09:12:11  [INFO ]  Recurse   : True
+2026-07-02 09:12:11  [INFO ]  Files to delete: 1245
+2026-07-02 09:12:12  [INFO ]  DELETED: D:\IIS\Logs\u_ex260101.log
+2026-07-02 09:12:12  [WARN ]  FAILED : D:\IIS\Logs\u_ex260102.log — file in use
+2026-07-02 09:13:05  [INFO ]  Completed in 00:00:53.42 — Deleted: 1244 | Failed: 1 | Total: 1245
+2026-07-02 09:13:05  [INFO ]  === Invoke-OldFilePurge finished ===
+```
+
+---
+
+# Progress reporting
+
+While running, the script displays a progress bar updated every 500 processed files (or on the last file), showing the count deleted, failed, and the deletion rate (files/second).
+
+---
+
+# Error Handling
+
+- Validates that `Path` exists and is a directory before starting.
+- Each file deletion is wrapped in `try/catch`; failures are counted and logged with `[WARN]` but do not stop the run.
+- Supports `-WhatIf` and `-Confirm` (via `SupportsShouldProcess`) to preview or confirm deletions before they happen.
+
+---
+
+# Notes
+
+- Files are matched purely on `LastWriteTime`; there is no filter on file extension or name.
+- Hidden and system files are included (`-Force`).
+- Deletion uses `[System.IO.File]::Delete()` instead of `Remove-Item`, which is significantly faster for large numbers of small files.