Call-stack information. Use
caller()
to find
out who’s calling this subroutine:
($package, $file, $line) = caller();
List of a package’s global variables. For a package
Foo
, %Foo::
contains the symbol
table, whose keys are names of global identifiers in that package and
whose values are typeglobs.
Find out what a reference contains. ref($r)
returns undef
if $r
is an
ordinary scalar, “SCALAR” if it is a reference to a
scalar (similarly “ARRAY,” “HASH,”
“CODE,” and “REF”) or the name of a package,
if $r
is a blessed object reference.
Object information:
$obj->isa("Foo"); # returns true if $obj inherits from Foo $obj->can("bar"); # returns true if it supports method "bar"