Launchd Auto

Apr 5, 2026

Example:

Automatically renames Jamf Connect.app to Jamf Connect 2.app the instant it appears in /Applications, using macOS-native launchd with kernel-level FSEvents (WatchPaths). Zero polling, zero lag.

Overview

Trigger	Action
`Jamf Connect.app` appears in `/Applications`	⚡ Fires immediately via WatchPaths
Mac boots / wakes from sleep	🔄 Runs once via `RunAtLoad`
Every day at 12:00 noon	🕛 Runs as final safety net

Step 1: Create the Rename Script

sudo nano /usr/local/bin/rename_jamf.sh

Paste the following:

#!/bin/bash

SRC="/Applications/Jamf Connect.app"
DST="/Applications/Jamf Connect 2.app"

if [ -d "$SRC" ]; then
    # Kill the app if it's running
    pkill -x "Jamf Connect" 2>/dev/null
    sleep 1

    # Remove destination if it already exists
    [ -d "$DST" ] && rm -rf "$DST"

    mv "$SRC" "$DST"
    echo "$(date): Renamed 'Jamf Connect.app' → 'Jamf Connect 2.app'" >> /var/log/rename_jamf.log
else
    echo "$(date): Source not found, skipping." >> /var/log/rename_jamf.log
fi

Make it executable:

sudo chmod +x /usr/local/bin/rename_jamf.sh

Step 2: Create the launchd Plist

sudo nano /Library/LaunchDaemons/com.local.rename-jamf.plist

Paste the following:

<?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.local.rename-jamf</string>

    <key>ProgramArguments</key>
    <array>
        <string>/bin/bash</string>
        <string>/usr/local/bin/rename_jamf.sh</string>
    </array>

    <!-- Trigger immediately when Jamf Connect.app appears -->
    <key>WatchPaths</key>
    <array>
        <string>/Applications/Jamf Connect.app</string>
    </array>

    <!-- Also run at boot as a safety net -->
    <key>RunAtLoad</key>
    <true/>

    <!-- Also run daily at 12:00 noon as a safety net -->
    <key>StartCalendarInterval</key>
    <dict>
        <key>Hour</key>
        <integer>12</integer>
        <key>Minute</key>
        <integer>0</integer>
    </dict>

    <key>StandardOutPath</key>
    <string>/var/log/rename_jamf.log</string>

    <key>StandardErrorPath</key>
    <string>/var/log/rename_jamf_error.log</string>

    <key>UserName</key>
    <string>root</string>

</dict>
</plist>

Step 3: Set Permissions & Load

# Set correct ownership and permissions
sudo chown root:wheel /Library/LaunchDaemons/com.local.rename-jamf.plist
sudo chmod 644 /Library/LaunchDaemons/com.local.rename-jamf.plist

# Load the daemon
sudo launchctl load /Library/LaunchDaemons/com.local.rename-jamf.plist

# Trigger immediately to test
sudo launchctl start com.local.rename-jamf

Step 4: Verify It Is Running

Check it’s loaded

sudo launchctl list | grep rename-jamf

Expected output:

-   0   com.local.rename-jamf

Column	Value	Meaning
PID	`-`	Idle (normal when not actively running)
Exit Code	`0`	✅ Last run succeeded
Exit Code	`1`	❌ Last run failed — check error log
Not listed	—	❌ Not loaded — reload it

Validate the plist syntax

plutil -lint /Library/LaunchDaemons/com.local.rename-jamf.plist

Expected: com.local.rename-jamf.plist: OK

Check the plist is in place

ls -la /Library/LaunchDaemons/com.local.rename-jamf.plist

Check logs

tail -20 /var/log/rename_jamf.log
tail -20 /var/log/rename_jamf_error.log

Management Commands

Action	Command
Load / enable	`sudo launchctl load /Library/LaunchDaemons/com.local.rename-jamf.plist`
Unload / disable	`sudo launchctl unload /Library/LaunchDaemons/com.local.rename-jamf.plist`
Reload after edits	`sudo launchctl unload ... && sudo launchctl load ...`
Trigger manually	`sudo launchctl start com.local.rename-jamf`
Check status	`sudo launchctl list \| grep rename-jamf`
Watch logs live	`tail -f /var/log/rename_jamf.log`

Why WatchPaths? — Performance Impact

Method	How it works	CPU/RAM impact
WatchPaths (launchd)	Kernel FSEvents — sleeps until file event fires	~0% — event-driven
`StartInterval` polling	Wakes every N seconds to check	Very low but wasteful
`while true; do sleep 1` loop	Constant process running	⚠️ Unnecessary overhead

WatchPaths is completely event-driven — the daemon is dormant until a filesystem change occurs at the watched path. It uses the same FSEvents mechanism as Spotlight and Time Machine. There is no noticeable performance impact on the Mac.

Why `/Library/LaunchDaemons/`?

Location	Runs as	When
`/Library/LaunchDaemons/`	root	At boot, before login ✅
`/Library/LaunchAgents/`	root	After login
`~/Library/LaunchAgents/`	current user	After user login

Renaming apps in /Applications requires root privileges, making LaunchDaemons the correct choice.

Does It Run When the MacBook Lid Is Closed?

No — both cron and launchd are paused when the Mac is asleep. However:

WatchPaths will fire immediately on wake if Jamf Connect.app appeared while asleep
RunAtLoad ensures it runs on every boot and wake
StartCalendarInterval catches up and runs on the next wake if the Mac was asleep at noon

This combination makes the setup resilient without needing the Mac to be awake 24/7.

File Summary

File	Purpose
`/usr/local/bin/rename_jamf.sh`	The rename script
`/Library/LaunchDaemons/com.local.rename-jamf.plist`	launchd daemon configuration
`/var/log/rename_jamf.log`	stdout log
`/var/log/rename_jamf_error.log`	stderr / error log