Global variables are global, and @_ are aliases. This is easily replicated and tested with the following code (your while loop will never terminate so I used a for loop instead):

#!perl -w
use strict;
use Data::Dumper;

my @someNameArray = qw(foo bar baz);
print Dumper \@someNameArray;

for(@someNameArray){
   print( "Before: $_\n" );# $_ correct
   frobnicate($_);
   print( "After : $_\n" );# $_ changed
}
print "Final:\n";
print Dumper \@someNameArray;

sub frobnicate {
    $_[0] = "changed value from '$_[0]'";
};

__END__

$VAR1 = [
          'foo',
          'bar',
          'baz'
        ];
Before: foo
After : changed value from 'foo'
Before: bar
After : changed value from 'bar'
Before: baz
After : changed value from 'baz'
Final:
$VAR1 = [
          'changed value from \'foo\'',
          'changed value from \'bar\'',
          'changed value from \'baz\''
        ];

[download]

If you

I suggest to use a lexical iterator instead of $_, and don't have your callees change elements in @_. Using a lexical iterator prevents action at a distance from called subroutines. Using @_ will need more changes and information about $finder->isExist(...).

In reply to Re: Does perl sub using stack and possible to crash? by Corion
in thread Does perl sub using stack and possible to crash? by anaconda_wly

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