Have a look at the IO::Scalar module which is part of the IO::Stringy distribution:

    #!/usr/bin/perl -w

    use strict;
    use IO::Scalar;

    my $str;

    tie *STDOUT, 'IO::Scalar', \$str;

    print "hello, world";

    untie *STDOUT;

    print "The data is here: ",$str;
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--
John.