kill zsh with USR1 every time a path directory changes

org.wholezero.watchpath.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>org.wholezero.watchpath</string>
	<key>ProgramArguments</key>
	<array>
		<string>/bin/zsh</string>
		<string>-lc</string>
		<string>fswatch -o "${path[@]}" | xargs -n1 -I{} pkill -USR1 -u "$UID" zsh</string>
	</array>
	<key>KeepAlive</key>
	<true/>
</dict>
</plist>
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For this to work, you need something like this in your ~/.zshrc:

TRAPUSR1() { rehash }

And you probably want something like this in ~/.zshenv:

[[ ! -o interactive ]] && TRAPUSR1(){}

Oh, I had a hard time getting this working. This is what worked for me in the end:

launchctl enable gui/$(id -u)/org.wholezero.watchpath
launchctl load -w ~/Library/LaunchAgents/org.wholezero.watchpath.plist