http://www.perlmonks.org?node_id=924479


in reply to Merging files, 1 line for every 10

I'm with others here wondering what possible purpose this serves, but I would probably do something like the below. $in_file1 being the larger of the two files. 

open($in_fh1, '<', $in_file1);
open($in_fh2, '<', $in_file2);
open($out_fh, '>', $out_file);

while (my $line1 = <$in_fh1>)
{
   chomp($line1);
   state $i;
   $i++;
   say {$out_fh} $line1;
   unless ($i % 10)
   {
      chomp(my $line2 = <$in_fh2>);
      say {$out_fh} $line2 if $line2;
   }
}

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Re^2: Merging files, 1 line for every 10
by trizen (Hermit) on Sep 07, 2011 at 21:59 UTC
    I'd recommend a simpler code: 
    open my $in_fh1, '<', $in_file1;
open my $in_fh2, '<', $in_file2;
open my $out_fh, '>', $out_file;

while (defined(my $line1 = <$in_fh1>)) {
    print {$out_fh} $line1;
    unless ($. % 10) {
        my $line = <$in_fh2>;
        print {$out_fh} $line;
    }
}

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[reply]
[d/l]

      The use of $. does make things more simple. I'll have to take note of that for similar situations in the future. What is the benefit of the added defined call?

[reply]
[d/l]
[select]

        It deals with the edge case where $line gets a value that is false before the actual end of file.

        True laziness is hard work
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