Are symbolic links and aliases the same thing on OS X?

Question

I have been trying to set up some symbolic links in the Terminal, and haven't been able to get them to work.

In trying to find what I was doing wrong, I compared their function to the "create alias" button in the right click menu.

My question is this: what is the difference between alias(es) and symbolic links in Mac OS X?

Solution

While symbolic links are a feature of the file system, aliases are a feature of OS X. I don't know if they still use that technique, but back in the days of Mac OS Classic or even System 7, they were a file with just a resource fork which had a special resource telling the OS what path AND what file-id the file had.

Symbolic links are more like a database entry on file system level. They differ from hard links in the point that they get invalid when you delete or move the target file. Hard links are actual file entries in the file systems catalog pointing to the same location on your storage medium.