stdinouterr.pl

use strict;
use warnings;
use utf8;

use Perl6::Say;
use String::CamelCase qw(camelize);



say "--- cat ---";
filter_print(\*STDIN, \*STDOUT, sub { shift });

# stdin, stdout, stderr are allowed!
say "--- cat ---";
filter_print(\*stdin, \*stdout, sub { shift });
say "--- cat >&2 ---";
filter_print(\*stdin, \*stderr, sub { shift });

# I like these words though.
say "--- simple camelized ---";
filter_print(\*STDIN, \*STDOUT, sub { ucfirst lc shift });
say "--- camelized by String::CamelCase ---";
filter_print(\*STDIN, \*STDOUT, sub { camelize shift });


sub filter_print {
    my ($in, $out, $sub) = @_;
    $out->print($sub->($_))  while (<$in>);
}