ON linux I’ve found that infact readlink -f $0 solves all the problems as it resolved relative paths and follows all the links correctly, the downside being mac’s don’t have gnu readlink by default! and the BSD equivalent has barely any functionality (That’s Reason no.343249 to look at moving to Ubuntu for me!)

However currently I’d ideally like a solution that works for Mac too. When I work out a portable solution I’ll update the post.

1) symlink chains (i.e. l2 symlinks to l1 symlinks to script). If the script is invoked as l2, you’ll get the directory of l1 instead of script.

2) relative symlinks. If the symlink is relative rather then absolute, the directory name you get needs to be interpreted relative to the symlinks directory.