http://qs321.pair.com?node_id=27460


in reply to Filehandle Filter

All right, here's a new version. This one has support for filtering and unfiltering filehandles by calling functions on them, as opposed to the object going out of scope method.

Usage below.

package Filter::Handle; use strict; sub import { my $class = shift; return if !@_; my $caller = caller; if ($_[0] eq "subs") { no strict 'refs'; for my $sub (qw/Filter UnFilter/) { *{"${caller}::$sub"} = \&{"${class}::$sub"}; } } } sub Filter { my $fh = $_[0]; tie *{ $fh }, __PACKAGE__, @_; } sub UnFilter { my $fh = shift; { local $^W = 0; untie *{ $fh } } } sub TIEHANDLE { my $class = shift; my $fh = shift or die "Need a filehandle."; my $output = shift || sub { my($file, $line) = (caller(1))[1,2]; sprintf "%s:%d - %s\n", $file, $line, "@_" }; bless { fh => $fh, output => $output }, $class; } sub new { Filter(@_[1..$#_]); bless { fh => $_[1] }, $_[0] } sub DESTROY { my $self = shift; UnFilter($self->{fh}); } sub PRINT { my $self = shift; my $fh = *{ $self->{fh} }; ## thanks, chromatic :) print $fh $self->{output}->(@_); } sub PRINTF { my $self = shift; my $fmt = shift; @_ = ($self, sprintf $fmt, @_); goto &PRINT; ## thanks, tilly :) } 1;
Usage is either what we had before:
my $f = Filter::Handle->new(\*STDOUT, sub { "Foo: @_\n" }); print "Bar";
Or the new
use Filter::Handle qw/subs/; Filter \*STDOUT, sub { "Foo: @_\n" }; print "Bar"; UnFilter \*STDOUT;