#!/usr/bin/perl -w

#  Notch out time when lines from 'tail -f' arrive so that lines
#  from different minutes are separated by a timestamp.

use strict;

{
    my $lastMinute = (localtime)[1];

    while(<>) {

        my $thisLine = $_;
        my $thisMinute = (localtime)[1];
        if ( $thisMinute != $lastMinute ) {

          $lastMinute = $thisMinute;
          print "\n";
          print scalar localtime;
          print "\n";
        }
        print $thisLine;
    }
}