my $logfile = "logfile";
open( LOG, "<$logfile" ) or die "$logfile: $!";

while (!$end_condition)
{
    while ( my $line = <LOG> ) {
        print $line;
    }
    sleep(1); # do something usefull 
    seek( LOG, 0, 1 );
}
close(LOG);

##</code><code>##

tie *LOG, "Tie::Tailrotate", "$logfile"; 
open ...

##</code><code>##

package Tie::Tailrotate;
use strict;  # ;-) learned that
use Carp;

sub TIEHANDLE {
    my $class = shift;
    my $fname = shift; 
    # need $fname to open file and initialize filehandle
    if ( $fname =~ /[>+|]/) {
        croak "Only read support for $fname\n"; }
    open my $self, $fname
        or croak "Open $fname failed:$!";
    # $self is  filehandle, 
    # but created is $$$self, @$$self and %$$self
    # see Camel Book: 14.4. Tying Filehandles
    $$self->{filename} = $fname;
    $$self->{curpos}   = 0;    
    return bless $self, $class;    # $self is a glob ref
}

sub OPEN { # needs to be covered
    my $self  = shift;
    my $fname = shift;
    $self->CLOSE;
    if ( $fname =~ /[>+|]/) {
        croak "Only read support for $fname\n"; }
    open $self, $fname
        or croak "Open $fname failed:$!";
    $$self->{curpos}   = 0;    
    $$self->{filename} = $fname;
    close($self);
    return 1;
}

sub READLINE {
    my $self = shift;
    my $line;
    my $size  = (stat $$self->{filename} )[7];
    # if the last position I read from is bigger than
    # actual file size, the file rotated. Continue
    # reading from last file, last position.
    my $use_active_file = ($$self->{curpos} <= $size );
    if ($use_active_file)
    {	# continue with active logfile
        open $self, $$self->{filename}
            or croak "Open $$self->{filename} failed:$!";
        seek ($self, $$self->{curpos}, 0 );
        $line = <$self>;  # undef if eof
        $$self->{curpos} = tell($self)  if ($line);
    } 
    else {  # File rotated, Log::Agent naming convention
        my $rot_fname = "$$self->{filename}.0";
        $size = (stat $rot_fname )[7];
        open $self, $rot_fname
            or croak "Open $rot_fname failed:$!";
        seek ($self, $$self->{curpos}, 0 );
        $line = <$self>; # undef if eof
        if ($line) { $$self->{curpos} = tell($self); }
        else 
        {  # reset position, to continue with active file
            $$self->{curpos} = 0;
        }
    }
    close($self); # unlock file
    return $line;
}