#!/usr/bin/perl -w

use strict qw(refs vars);
use POSIX;

our $polltime= 60;
our $logfile= "/var/log/news.notice";

our ($loghandle, $logfile_devino);

sub current_devino () { return join '.', (stat _)[0..1]; }

our %months;
$months{ (qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec))[$_] }= $_
    foreach qw(0..11);

sub processline_core ($) {
    local ($_) = @_;
    my ($mon,$dom,$h,$m,$s) = 
	s/^ ([A-Z][a-z]{2}) [ ]
	    ([ 013]\d) [ ]
	    ([ 0-2]\d) : (\d\d) : (\d\d) [ ]
	    [-0-9a-z]+ /x;
    return "date re not matched" unless defined $mon;
    $mon= $months{$mon};
    return "unknown month $mon" unless defined $mon;

    my $isdst= 0;
    $ts= mktime($s,$m,$h, $dom,$current_year, 0,0, $isdst);
    $last_ts= 
}

sub backlog () {
    my $fh= new IO::File '<', "$logfile.0";
    if (!$fh) {
	die "$logfile.0 $!" unless $!==&ENOENT;
	return;
    }
    while (defined(my $l= <$fh>)) {
	$l =~ s/\n$// or last;
	processline($l);
    }
    close $fh;
}
    
sub logpoll () {
    my $lbuf= '';
    my $waited_eol= 0;
    
    for (;;) {
	sleep($polltime);

	if (!$loghandle) {
	    $loghandle= new IO::File '<', $logfile;
	    if (!$loghandle) {
		die "$logfile $!" unless $!==&ENOENT;
		next;
	    }
	    stat $loghandle or die $!;
	    $logfile_devino= join '.', (stat _)[0..1];
	}

	for (;;) {
	    if ($lbuf =~ s/\n$//) {
		processline($l);
		$lbuf= '';
	    }
	    my $xtra= <$loghandle>;
	    if (!defined $xtra) {
		die "$logfile $!" if $loghandle->error;
		last;
	    }
	    $lbuf .= $xtra;
	}

	if (stat $logfile) {
	    next if $logfile_devino eq current_devino;
	} else {
	    die "$logfile $!" unless $!==&ENOENT;
	}

	# current file is no longer right
	if (length $lbuf) {
	    # wait for the rest of the line ?
	    next unless $waited_eol++ > 3;
	}
	$lbuf= '';
	close $loghandle;
	$loghandle= undef;
    }
}

backlog();
logpoll();