jlogtail.pl

#!/usr/bin/perl
use strict;
use warnings;

use JLog::Writer;
use JLog::Reader;

use Compress::Zlib;
use Getopt::Long;
use Fcntl;

my $compressed;
my $count = 1;
my $jlog_path;

GetOptions("z" => \$compressed,
           "n=i" => \$count,
           "path=s" => \$jlog_path);
print STDERR "jlog_path=$jlog_path\n";
print STDERR "compressed=$compressed\n";

$SIG{'INT'} = 'cleanup';
sub cleanup {
    my $queue_writer = JLog::Writer->new($jlog_path, O_CREAT);
    $queue_writer->open;
    $queue_writer->remove_subscriber('jlogtail');
    $queue_writer->close;
    exit();
}

my $queue_writer = JLog::Writer->new($jlog_path, O_CREAT);
$queue_writer->open;
$queue_writer->add_subscriber('jlogtail');
$queue_writer->close;

my $queue_reader = JLog::Reader->new($jlog_path);
$queue_reader->open('jlogtail');

for (my $i = 0; $i < $count; $i++) {
    my $msg = $queue_reader->read;
    if ($compressed) {
           $msg = Compress::Zlib::memGunzip($msg);
    }
    print "$msg\n";
}

$queue_reader->close;
cleanup();