How macOS actually works

The three kinds of shortcut

Updated 2026-07-31 · 4 min read

macOS has three ways to point at a file and they behave very differently.

The three

Type	Made by	Survives the target moving
Alias	Finder (⌘L)	Yes — tracks by file ID
Symlink	ln -s	No — stores a path
Hard link	ln	Yes — it *is* the file

Aliases

A Finder alias records both a path and the file's unique ID, so it keeps working when you move the target. It is a macOS-specific format, and the Terminal treats it as an ordinary small file rather than following it.

Symlinks

The Unix standard. Stores a path; breaks if the target moves.

ln -s /path/to/original /path/to/link
find ~ -type l                        # find all symlinks
find ~ -type l ! -exec test -e {} \; -print   # find broken ones

That last command is worth keeping — broken symlinks accumulate silently after moving folders around.

Hard links

A second directory entry pointing at the same data. There is no "original"; the data survives until every link is deleted.

ln original.txt second-name.txt

Time Machine used hard links extensively before APFS snapshots.

Why this matters for search

A search tool that follows symlinks can loop forever — a link pointing at its own ancestor creates an infinite tree. Well-built indexers record symlinks but never follow them, which is why a linked folder may appear once rather than being traversed twice.

Hard links are the harder case: the same data with two names, both real, and neither a duplicate in any meaningful sense.

Common questions

What is the difference between an alias and a symlink?

An alias tracks the file even if it moves; a symlink stores a path and breaks. Terminal tools follow symlinks but not aliases.

How do I find broken symlinks?

find ~ -type l ! -exec test -e {} \; -print