Überprüfen, ob eine Referenz geblesst ist

Was ist geblesst?

      bless REF,CLASSNAME
      bless REF
              This function tells the thingy referenced by REF
              that it is now an object in the CLASSNAME package.
              If CLASSNAME is omitted, the current package is
              used.  Because a "bless" is often the last thing
              in a constructor, it returns the reference for
              convenience.  Always use the two-argument version
              if the function doing the blessing might be inher-
              ited by a derived class.  See perltoot and perlobj
              for more about the blessing (and blessings) of
              objects.

              Consider always blessing objects in CLASSNAMEs
              that are mixed case.  Namespaces with all lower-
              case names are considered reserved for Perl prag-
              mata.  Builtin types have all uppercase names, so
              to prevent confusion, you may wish to avoid such
              package names as well.  Make sure that CLASSNAME
              is a true value.

              See "Perl Modules" in perlmod.

Überprüfung

Möglichkeit 1

#! /usr/bin/perl

use strict;
use warnings;
use CGI;

my $cgi = CGI->new();

print "it's an object\n" if UNIVERSAL::isa($cgi,'UNIVERSAL');

  it's an object

Möglichkeit 2

#! /usr/bin/perl

use strict;
use warnings;
use CGI;
use Scalar::Util qw(blessed);

my $cgi = CGI->new();

print blessed($cgi);

  CGI

Möglichkeit 3

sub blessed {
   my $obj = shift;
   return (UNIVERSAL::isa($obj, 'UNIVERSAL') ? ref($obj) : undef);
}

Ergänzungen, Kommentare

---+++ Main.??? - 14 Jul 2003 - Betreff