Linux Magazine: Fit To Be Tied, Part One
May 09, 2005, 05:30 (0 Talkback[s])
(Other stories by Randal L. Schwartz)
"You may have heard the term tied variable before, especially if
you've accessed a DBM- based hash, but what is a tied variable and
why would you use one? This month and next, let's take a look.
"A tied variable is a variable that presents a relatively normal
outward appearance to the rest of your Perl program but has
additional wiring on the inside. Specifically, nearly all of the
operations on the variable (fetching its value, updating a hash
element, getting the length of an array) trigger subroutine calls
that replace Perl's normal internal operations on variables. The
subroutines can perform anything you wish, although each one must
return an appropriate value if the corresponding outward action is
looking for one..."