UNIVERSAL - base class for ALL classes (blessed references)
use UNIVERSAL qw(isa); $yes = isa($ref, "HASH"); $io = $fd->isa("IO::Handle"); $sub = $obj->can('print');
UNIVERSAL is the base class which all bless references will inherit from, see perlobj
UNIVERSAL
UNIVERSAL provides the following methods
isa returns true if REF is blessed into package TYPE or inherits from package TYPE.
isa
REF
TYPE
isa can be called as either a static or object method call.
can checks if the object has a method called METHOD. If it does then a reference to the sub is returned. If it does not the undef is returned.
can
METHOD
can can be called as either a static or object method call.
VERSION will return the value of the variable $VERSION in the package the object is blessed into. If REQUIRE is given then it will do a comparison and die if the package version is not greater than or equal to REQUIRE.
VERSION
$VERSION
REQUIRE
VERSION can be called as either a static or object method call.
UNIVERSAL also optionally exports the following subroutines
isa returns true if the first argument is a reference and either of the following statements is true.
REF is a blessed reference and is blessed into package TYPE or inherits from package TYPE
REF is a reference to a TYPE of perl variable (er 'HASH')
To install lib, copy and paste the appropriate command in to your terminal.
cpanm
cpanm lib
CPAN shell
perl -MCPAN -e shell install lib
For more information on module installation, please visit the detailed CPAN module installation guide.