Linux：定时删除嵌套目录中过期一周的PDF文件（仅删文件）

First, let’s break down what you need: a recursive search for PDF files older than 7 days in your users directory structure, delete only those files (leave directories intact), and schedule this to run automatically via cron.

Step 1: Test the File Deletion Command #

Before setting up cron, always test the command manually to ensure it targets the right files. Run this in your terminal:

find /full/path/to/users -type f -name "*.pdf" -mtime +7

This will list all PDF files modified more than 7 days ago (the +7 means "older than 7 days"). Verify the list is correct—once you’re confident, add the -delete flag to actually remove them:

find /full/path/to/users -type f -name "*.pdf" -mtime +7 -delete

Let’s break down each part:

• /full/path/to/users: Replace this with the absolute path to your top-level users directory (critical for cron, since it doesn’t use your shell’s working directory).
• -type f: Ensures we only target files (not directories).
• -name "*.pdf": Filters for only PDF files.
• -mtime +7: Selects files modified more than 7 days ago.
• -delete: Removes the matched files (only use this after testing!).

Step 2: Set Up the Cron Task #

To schedule this to run regularly (e.g., daily at 2 AM, when server load is low):

1. Open your user’s crontab editor:

crontab -e

2. Add the following line to the end of the file:

0 2 * * * find /full/path/to/users -type f -name "*.pdf" -mtime +7 -delete

Let’s explain the cron schedule:

• 0: Minute (0 minutes past the hour)
• 2: Hour (2 AM, using 24-hour format)
• *: Every day of the month
• *: Every month
• *: Every day of the week

3. Save and exit the editor (in nano, that’s Ctrl+O, Enter, then Ctrl+X). Cron will automatically apply the new schedule.

Important Notes #

• Permissions: Ensure the user running the cron task has write access to all the PDF files you want to delete. If you’re using a system cron job (instead of a user crontab), you might need to run it as root or adjust file permissions accordingly.
• Log Output: If you want to log what’s deleted (for debugging), modify the cron line to redirect output to a log file:

  0 2 * * * find /full/path/to/users -type f -name "*.pdf" -mtime +7 -delete >> /var/log/pdf_cleanup.log 2>&1
  

• Dry Run First: Always run the find command without -delete first to avoid accidentally removing the wrong files.

That’s it! This setup will automatically clean up old PDFs every day while leaving your directory structure untouched.

内容的提问来源于stack exchange，提问作者Robert Moritz