ln -s /path/to/original /path/to/symlink// or to use echo use the commands below $ echo content > original $ ln -s original symlink $ ls -la original symlink -rw-r--r-- 1 admin staff 8 28 Mar 10:04 original lrwxr-xr-x 1 admin staff 8 28 Mar 10:04 symlink -> original $ cat symlink content
To create a symlink to replace the system directory, you have to disable System Integrity Protection. And you then can re-enable it after the symlink is set up.