A symbolic link is a special type of file that refers to another file or directory and is most often encountered in UNIX derived/inspired operating systems and their file systems. Symbolic links are real files that contain a path which is automatically resolved when the link is accessed.
There are multiple ways of handling symbolic links during path resolution: Some operating systems maintain the hierarchy of the path leading to the symlink while others substitute the entire hierarchy of the path for that of the target. UNIX-like operating systems handle this in a strange way: The kernel and C library do the latter while some shells maintain a history of path changes and resolve the parent of a symlinked directory as the parent of the symlink.
Example: On a system substituting the hierarchy (Linux, glibc, shown as shell commands for clarity) :
$ ln -T /dir1/sdir1 /dir2/sdirlink1 $ cd /dir2/sdirlink1 $ pwd /dir1/sdir1 $ cd .. $ pwd /dir1 $ cd / $ cd /dir2/sdirlink1/.. $ pwd /dir1
On a system maintaining the symlink's hierarchy (posnk (old version), newlib, shown as shell commands for clarity) :
$ ln -T /dir1/sdir1 /dir2/sdirlink1 $ cd /dir2/sdirlink1 $ pwd /dir2/sdirlink1 $ cd .. $ pwd /dir2 $ cd / $ cd /dir2/sdirlink1/.. $ pwd /dir2