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#!/usr/bin/perl -w
# vim: ts=2 sw=2 filetype=perl expandtab
# Make sure that the default behavior for POE::Wheel::FollowTail is to
# skip to the end of the file when it first starts.
use warnings;
use strict;
sub POE::Kernel::ASSERT_DEFAULT () { 1 }
use IO::Handle;
use POE qw(Wheel::FollowTail Filter::Line);
use Test::More tests => 2;
my $filename = 'bingos-followtail';
# Using "!" as a newline to avoid differences in opinion about "\n".
open FH, ">$filename" or die "$!\n";
FH->autoflush(1);
print FH "moocow - this line should be skipped!";
POE::Session->create(
package_states => [
'main' => [qw(_start _input _error _shutdown _file_is_idle)],
],
inline_states => {
_stop => sub { undef },
},
heap => { filename => $filename, },
);
$poe_kernel->run();
exit 0;
sub _start {
my ($kernel,$heap) = @_[KERNEL,HEAP];
$heap->{wheel} = POE::Wheel::FollowTail->new(
Filter => POE::Filter::Line->new( Literal => "!" ),
Filename => $heap->{filename},
InputEvent => '_input',
ErrorEvent => '_error',
IdleEvent => '_file_is_idle',
);
$heap->{running} = 1;
$heap->{counter} = 0;
print FH "Cows go moo, yes they do!";
close FH;
return;
}
sub _shutdown {
delete $_[HEAP]->{wheel};
return;
}
sub _input {
my ($kernel,$heap,$input) = @_[KERNEL,HEAP,ARG0];
# Make sure we got the right line.
is($input, 'Cows go moo, yes they do', 'Got the right line');
ok( ++$heap->{counter} == 1, 'Cows went moo' );
POE::Kernel->delay( _shutdown => 5 );
return;
}
sub _error {
my ($heap,$operation, $errnum, $errstr, $wheel_id) = @_[HEAP,ARG0..ARG3];
diag("Wheel $wheel_id generated $operation error $errnum: $errstr\n");
POE::Kernel->delay( _shutdown => 0.01 );
return;
}
sub _file_is_idle {
return unless $_[HEAP]{counter};
# At first I thought just a delay( _shutdown => 1 ) would be nice
# here, but there's a slight chance that the POE::Wheel::FollowTail
# polling interval could refresh this indefinitely.
#
# So I took the slightly more awkward course of turning off the
# shutdown timer and triggering shutdown immediately.
POE::Kernel->delay(_shutdown => undef);
POE::Kernel->yield("_shutdown");
}
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