Add Find A File Installed By Brew as a unix til

unix/find-a-file-installed-by-brew.md

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+# Find A File Installed By Brew
+
+I installed a homebrew formula to satisfy a dependency for a Rails application.
+Related to [the whole mimemagic
+debacle](https://github.com/rails/rails/issues/41750), I had run [`brew install
+shared-mime-info`](https://formulae.brew.sh/formula/shared-mime-info). The
+specific file that Rails needed from this install was `freedesktop.org.xml`.
+
+It took me two commands to figure out if that file had been included and where
+it was living.
+
+The first was to find the _brew prefix directory_ — the place where homebrew
+had installed everything related to `shared-mime-info`.
+
+```bash
+$ brew --prefix shared-mime-info
+/usr/local/opt/shared-mime-info
+```
+
+Now that I know about that directory, I can use
+[`fd`](https://github.com/sharkdp/fd)—a more user-friendly alternative to
+`find`—to _find_ the specific file in that directory. Not wanting to cast too
+narrow of a net, I decided to look for any `xml` file in that directory.
+
+```bash
+$ fd -e xml . /usr/local/opt/shared-mime-info
+/usr/local/opt/shared-mime-info/share/shared-mime-info/packages/freedesktop.org.xml
+```
+
+The `-e` flag specifies the file extension. The `.` is the first argument, the
+pattern to look for. In this case, anything. The second argument
+(`/usr/local/opt/shared-mime-info`) is the path to look within. In this case,
+the brew prefix for the `shared-mime-info` package.