What Is a Symbolic Link? A Pointer to Another Path
A symbolic link, or symlink, is a special file that points to another file or directory by its path, acting as a transparent shortcut.
A symbolic link is a small file whose contents are just a path to another location. When you access the symlink, the OS follows it to the target. Symlinks show up in CI for things like tool version managers and node_modules layouts, and they have quirks worth knowing, especially around caching and archiving.
What a symlink is
A symlink stores a path to a target. Reading or writing through the symlink redirects to that target. If the target moves or is deleted, the symlink becomes "dangling" and points nowhere.
Creating one
You create a symlink with ln -s target linkname. The -s flag means symbolic; without it you would create a hard link, which is a different thing entirely.
Symlink versus hard link
- A symlink points to a path and can cross filesystems.
- A symlink can target a directory; a hard link usually cannot.
- If the target is deleted, a symlink dangles but a hard link still works.
Where symlinks appear
Version managers like nvm symlink the active toolchain; package layouts sometimes symlink shared dependencies. They let many references share one real location without copying.
Symlinks in CI
Caching and artifact archiving can mishandle symlinks, either following them and duplicating data, or breaking them so they dangle. When a cached directory contains symlinks, verify they survive a cache restore, or builds can fail mysteriously.
Links on managed runners
On Latchkey runners, symlinks behave like any Linux filesystem. If your dependency cache relies on symlinks, confirm the cache preserves them so restored builds resolve to the right targets.
Key takeaways
- A symbolic link is a file that points to another path, like a shortcut.
- Create one with
ln -s; it dangles if the target disappears. - In CI, caching and archiving can break symlinks, so verify they survive.