#!perl -sw
use strict;
$^W=0;

my @instances = ('a', 'b', 'c');

sub screwed {
	my ($in) = @_;
	open(IN, '<', $in);
	print "before while: @instances\n";
#	while(local $_ = <IN>) {
	while(<IN>) {
		chomp;
		print "after while: @instances\n";
		print "file $in contains $_\n";
	}
	close(IN);
}


print "before $_\n" for @instances;
screwed $_ for @instances;
print "after $_\n" for @instances;
__END__
P:\test>test
before a
before b
before c
before while: a b c
after while: a1 b c
file a contains a1
after while: a2 b c
file a contains a2
before while:  b c
after while:  b1 c
file b contains b1
after while:  b2 c
file b contains b2
before while:   c
after while:   c1
file c contains c1
after while:   c2
file c contains c2
after while:   c3
file c contains c3
after
after
after