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Re^6: Stupid question (mortalization)

by runrig (Abbot)
on May 11, 2012 at 23:52 UTC ( #970118=note: print w/ replies, xml ) Need Help??


in reply to Re^5: Stupid question (mortalization)
in thread Stupid question

Seems like there are just bugs related to altering function arguments, perhaps when they also refer to more global variables, and maybe especially @ARGV. E.g. (copied and modified from bizarre Carp - also I posted a patch in that thread):

use Carp; Main(@ARGV); sub Main { my $first = shift @ARGV; $ARGV[0] = [qw(1 2 3)]; confess "Rubbish"; exit; }

I get different results on different versions of perl (tested on 5.8.4, 5.8.8, and 5.14.1). And different results when I comment out the assignment to $ARGV[0].

But passing @ARGV to Main() and then modifying @ARGV (and Getopt::* modules modify @ARGV by default -- so yes @_ should be copied and parsed instead) seems to be a bad thing (bad in that it triggers bugs in perl/Carp, not that you shouldn't be allowed to do it and perl should blow up).


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