Perl not able to tail rotated log file - perl

Question

I am using property based filters of rsyslog to send specific logs to seperate file where those logs will be parsed using perl.
This is my rsyslog entry
$template SPLIT,"/home/shivam/hello-%$YEAR%%$MONTH%%$DAY%%$HOUR%%$MINUTE%"
:msg, contains, "hello" -?SPLIT
So rsyslog will create separate files for logs coming after every minute. Files will be created like this hello-201505281139.
My perl script to parse these files is
use strict;
use warnings;
use POSIX qw(strftime);
my $date = strftime "%Y%m%d%H%M", localtime;
my $file = '/root/defer-'.$date;
open(my $fh,'<',$file) or die "unable to open file $!\n";
while(1) {
while(my $line = <$fh>){
print "$date\n";
print "$line";
}
sleep(2);
unless ($date == strftime "%Y%m%d%H%M", localtime) {
close($fh);
$date = strftime "%Y%m%d%H%M", localtime;
$file = '/root/defer-'. $date;
system("touch $file");
open(my $fh,'<',$file) or die "unable to open file $!\n";
}
}
In unless block i am checking that if minute has changed then i close previous file and open new file.
The reason i am creating new file from script and not waiting for rsyslog to create file is that the frequency of logs coming is not that much. So i create file and just start reading on it in hope that when any new log will come i will be able to read that.
But what is happening is that i am able to create new file but not able to read anything from that file.
This is what i am getting as warning
readline() on closed filehandle $fh at test.pl line 14.
Line 14 in my code is this line
while(my $line = <$fh>){
I am not able to see anything wrong in my code. Please suggest what is the mistake.

Answer 1

You have two different $fh lexical (my) variables,
So instead declaring new one
open(my $fh,'<',$file) or die "unable to open file $!\n";
keep using previously declared one,
open($fh,'<',$file) or die "unable to open file $!\n";