Automating Directory Structure Backup

27 Mar, 2025

Problem:

• When vibe-coding full-stack applications, a good hack I have found is giving the directory structure of the entire project (minus the node_modules and lib folders of python etc.) it gives the LLM tool a better understanding of the project and quality of responses also improve.
• Now instead of running this every time I want directory_structure to be updated every hour or to run at a specified duration automatically.
• To achieve this, I setup a cron here, that runs the tree command and creates a new file inside directory-structure folder in the root of the project.

Solution

Step 1:

1. First, create a shell script that will generate the directory structure file with the current date.

2. Then set up a cron job to run this script hourly.

#!/bin/bash

# Set your project directory
PROJECT_DIR="/Users/anmoltomer/Desktop/side-projects/rent-tracker-wizard"
OUTPUT_DIR="$PROJECT_DIR/directory-structure"

# Create directory if it doesn't exist
mkdir -p "$OUTPUT_DIR"

# Generate filename with current date
FILENAME="project_directory_structure_$(date +'%Y-%m-%d').txt"

# Generate the directory structure
cd "$PROJECT_DIR" && tree -L 5 --prune -I 'node_modules|venv|.expo|__pycache__|backend/app/lib|*.pyc' > "$OUTPUT_DIR/$FILENAME"

# Optional: Add a timestamp to the file
echo -e "\n\nLast updated: $(date)" >> "$OUTPUT_DIR/$FILENAME"

3. Make the script executable

cd scripts && chmod +x update_directory_structure.sh

Step 2: Set Up the Cron Job

1. Open your crontab file: EDITOR=nano crontab -e

2. Add this line to run the script hourly (at the top of the hour):

0 * * * * /bin/bash /Users/anmoltomer/Desktop/side-projects/rent-tracker-wizard/scripts/update_directory_structure.sh

3. If you want to run it at a different minute (e.g., 15 minutes past the hour), change the first number:

15 * * * * /bin/bash /Users/anmoltomer/Desktop/side-projects/rent-tracker-wizard/scripts/update_directory_structure.sh

Alternative: Use a Launch Agent (macOS specific)

If you're on macOS, you might prefer to use a Launch Agent:

1. Create a plist file at ~/Library/LaunchAgents/com.user.dirstructure.plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.user.dirstructure</string>
    <key>ProgramArguments</key>
    <array>
        <string>/bin/bash</string>
        <string>/path/to/update_directory_structure.sh</string>
    </array>
    <key>StartInterval</key>
    <integer>3600</integer> <!-- Run every 3600 seconds (1 hour) -->
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>

2. Load the agent:

launchctl load ~/Library/LaunchAgents/com.user.dirstructure.plist

Verification

To verify it's working:

1. Wait for the next hour to pass
2. Check that a new file is created in your directory-structure folder
3. The next day, verify that a new file with the new date is created

This setup will automatically create a new file each day (named with that day's date) and update it hourly while you're working on that day.

Debugging

• To verify if the cron ran properly

1. Check cron logs (most reliable method) grep CRON /var/log/syslog

2. on macOS: grep cron /var/log/system.log

• Check if your output file was updated: ls -l /Users/anmoltomer/Desktop/side-projects/rent-tracker-wizard/directory-structure/ (Check the modification timestamp of your file)

• Check mail for cron errors (cron sends output to mail): mail -> Press 1 to see the details of cron run.

Deleting a Cron

Method 1: Remove the Cron Job via crontab

1. Open your crontab for editing (using nano): EDITOR=nano crontab -e
2. Find the line that contains:

/bin/bash /Users/anmoltomer/Desktop/side-projects/rent-tracker-wizard/scripts/update_directory_structure.sh

3. Delete the entire line (in nano, move cursor to the line and press Ctrl+K to cut it).

4. Save & exit (Ctrl+O → Enter → Ctrl+X).

5. Verify it’s gone: crontab -l (Should no longer show the job.)

Method 2: Completely Clear All Cron Jobs (Nuclear Option) 🔴

• If you want to remove ALL cron jobs for your user: crontab -r

Alternative:

• If You Used launchd (Alternative to Cron)
• If you previously set up a launchd job on your mac (.plist file), remove it with:

launchctl unload ~/Library/LaunchAgents/local.dirstructure.plist
rm ~/Library/LaunchAgents/local.dirstructure.plist

Why this works

• crontab -e edits your user’s personal cron jobs.

• Deleting the line stops the script from running hourly.

• No leftover processes or files remain (unlike launchd).