Your launch agents, in the menu bar

At a glance

One row per launch agent: the switch is on when it is loaded into launchd, and a running process shows its pid. Loaded agents come first.

One flip

The menu stays open after loading or unloading and shows the real state when it is done. If it fails, you get what launchctl said.

Always current

The list is read again every time you open the menu, so it never shows stale state.

Knows “disabled”

Agents disabled with launchctl disable are marked. Turning one on re-enables it first, then loads it.

Readable names

Give a cryptic label a name you recognise in settings.json.

Chinese and English

Follows the system language, or pick one in the menu.

Automatic updates

Checks and downloads new versions in the background, verifies them, and waits for you to install.

Bollard starts nothing and supervises nothing itself. It is a remote control for launchd, which ships with macOS: it reads launchd’s state into a menu and runs one launchctl command when you flip a switch.

What a launch agent is

launchd is the macOS process that starts background services and keeps an eye on them. Each plist in ~/Library/LaunchAgents describes one service; at login launchd goes through the folder and loads them. Bollard only touches this folder, so it never needs an administrator password.

Three layers of state

Whether the plist is in the folder decides if it loads at the next login. Loaded or not is whether launchd knows about it right now, and lasts until you log out. Disabled is a flag stored by launchd: loading is refused while it is set, and it survives a restart.

Where the list comes from

Every time the menu opens: list the plists and read each Label, ask launchctl list which are loaded and their pids, ask launchctl print-disabled which are disabled, and match them by Label. Nothing polls in the background.

Flipping a switch

On runs launchctl bootstrap (after launchctl enable for a disabled agent); off runs launchctl bootout. launchctl’s exit code is unreliable, so success is judged by the state it is actually in afterwards.

On, but no pid

Some agents are the service itself, such as redis: they show a pid, and switching them off stops the service. Others are only a trigger, such as an app’s launch-at-login item: it runs open once to start the app and exits, so it is on with no pid. Switching it off does not quit the app; it just stops it starting at the next login.

Run these two lines in a terminal. Bollard installed this way opens without a prompt.

$ curl -fL https://bollard.tianyw0.xyz/Bollard.zip \
    -o ~/Downloads/Bollard.zip
$ unzip -o ~/Downloads/Bollard.zip -d /Applications

Bollard is ad-hoc signed and not notarized by Apple. If you download it with a browser, macOS blocks the first launch; go to System Settings → Privacy & Security and click Open Anyway.

Unloading an agent lasts until you log out: its plist is still in LaunchAgents, so macOS loads it again at the next login.

Current version

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System

macOS 11 or later

Chip

Universal for Intel and Apple silicon, one package

Scope

The current user’s ~/Library/LaunchAgents

How it applies

launchctl bootstrap / bootout, no administrator password

Signature

Ad-hoc, not notarized

SHA-256

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