readlink
See the current Perl documentation for readlink.
Here is our local, out-dated (pre-5.6) version:
readlink - determine where a symbolic link is pointing
readlink EXPR
readlink
Returns the value of a symbolic link, if symbolic links are implemented. If
not, gives a fatal error. If there is some system error, returns the
undefined value and sets $!
(errno). If
EXPR is omitted, uses $_
.