replace '<$file' with "<$file" fix my problem. Thanks a lot for your suggestion.

--here is my original question--

Hello, I am trying to copy multiple files to their corresponding output file as following: 


use warnings;
use strict;
use IO::File;
use diagnostics;

my @handles;
my @temp;

foreach my $file ( glob( '*.input' ) ) {
        (my $out = $file) =~ s/\.input$/.output/;
        push @handles, [
                (IO::File->new('<$file') || die "die here\n"),
                (IO::File->new('>$out') || die "die under\n"),
        ];
}
#push @handles, [ (IO::File->new('</etc/hosts') || die "die here\n"), 
+(IO::File->new('>/tmp/hostlist') || die "die under\n"), ];

while (@handles) {
  @handles = grep {
    if (defined(my $line = $_->[0]->getline)) {
      print { $_->[1] } $line;
    } else {
      0;
    }
  } @handles;
}

[download]
It complains "Uncaught exception from user code:". If I don't use foreach loop, only copy one file as indicated in the commented out line. It is working fine.

What is wrong with the loop? Thanks in advance!

In reply to anonymous file handler objects by roadtest

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