i am trying to edit the contents of each file in one folder and trying to save in another copy in another folder the code is shown below. after executing code i am getting 'readline() on unopened filehandle perl at line 21' error. please help me. 

use strict;
use warnings;

sub variable;

my $indirname = $ARGV[0];
my $variable = 00001;
my $outdirname = "F:/TTS_RA_work/convert/edited";

opendir ( DIR, $indirname ) || die "Error in opening dir $indirname\n"
+;
my @files = grep(/.lab/,readdir(DIR));
closedir(DIR);


foreach my $filename( @files ){
    my $file = "text_000".$variable."."."lab";
    my $outfile = "$outdirname/"."$file";
    open my $output , ">$outfile" || die "Can't open the output file!"
+;
    print "file: $file\n";
    while ( my $line = <$filename> ) {
        $line =~ s/^\s+//;
        $line =~ s/ +/ /g;
        $line =~ s/\s+$/\n/g;
        print $output $line;
    }
    close ($output);
    $variable++;
}

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In reply to help with error 'readline() on unopened filehandle' by bhargavkanakiya

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