hi, i am pretty new to perl but this one really confuses me...i have taken some code and tried to make it as minimal as possible for the problem i'm getting

consider 'blah.pl' 

#!/usr/bin/perl
use strict;
sub screwed {
  my ($in) = @_;
  open(IN, "<$in");
  while(<IN>) { print "file $in contains $_"; }
  close(IN);
}
my @instances = ("a", "b");
map { print "before $_\n" } @instances;
map { screwed "$_"; } @instances;
map { print "after $_\n" } @instances;

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and data file 'a' 
a1
a2

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and data file 'b' 
b1
b2

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running this i get 
before a
before b
file a contains a1
file a contains a2
file b contains b1
file b contains b2
after
after

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what has happened to the entries of instances? they are there but are empty (null?)

if i remove the while (<IN>) line i get what i expect... 

before a
before b
opening file named a
opening file named b
after a
after b

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so why does iterating over the <IN> with a while kill my instances list?!! i don't get it...

was getting this with a suse7 locally built perl5.6 and thinking it was (maybe) a perl bug i rebuily perl5.8.0 locally and am still getting it.. :( mat

In reply to opening a file destroys nulling entries in a list?!?! by matpalm

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