Bookmarks is a command line utility for creating and resolving bookmarks of files and directories. Bookmarks, or aliases, are similar to symlinks, with the added benefit that they keep working even if the item they point to gets renamed and / or moved. They are usually created by invoking a contextual menu item or by command-option-dragging the item in the Finder. Though their format isn't completely documented, we can leverage some Foundation APIs to create them programmatically and make them a little more convenient to deal with.
The interface consists of the two subcommands create <source> <target> and resolve <target>. The latter writes the absolute path of the bookmarked item to stdout.
$ cd /Users/Tesch/Desktop/
$ touch ❤️.txt
$ bookmarks create ❤️.txt 📦.txt
$ mv ❤️.txt ../Documents/💙.txt
$ bookmarks resolve 📦.txt
/Users/Tesch/Documents/💙.txt