Add List All Services Managed By Brew as a Brew TIL

Author: jbranchaud

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
 For a steady stream of TILs, [sign up for my newsletter](https://crafty-builder-6996.ck.page/e169c61186).
 
-_1416 TILs and counting..._
+_1417 TILs and counting..._
 
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@@ -99,6 +99,7 @@ _1416 TILs and counting..._
 ### Brew
 
 - [Configure Brew Environment Variables](brew/configure-brew-environment-variables.md)
+- [List All Services Managed By Brew](brew/list-all-services-managed-by-brew.md)
 
 ### Chrome
 

brew/list-all-services-managed-by-brew.md

@@ -0,0 +1,28 @@
+# List All Services Managed By Brew
+
+Daemonized services, such as PostgreSQL, can be installed and managed with
+Homebrew. Under the hood `brew` uses `launchctl` on Mac to manage these
+services — i.e. starting, restarting, and stopping them.
+
+Assuming you've already installed some services, you can run `brew services
+list` to see what services there are and what their current status is.
+
+```bash
+$ brew services list
+Name          Status  User       File
+mailhog       none
+mysql         none
+postgresql@11 started jbranchaud ~/Library/LaunchAgents/[email protected]
+postgresql@13 none
+postgresql@16 none
+unbound       none
+```
+
+This is the default behavior if you just run `brew services` without a subcommand.
+
+This is helpful if you are, for instance, trying to see which PostgreSQL server
+version you are currently running and which other ones are available to run. I
+might then issue a `stop` to `postgresql@11` so that I can then `start` the
+`postgresql@16` service.
+
+See `brew services --help` for more details.