After having read the linked thread, I'm still not sure what your message is with respect to forking.

For all practical matters, there's no real differnce between accessing an "our" vs. a "my" variable from within a child process.  In both cases, the child has access to the variable's value as it was at the time of the fork, but as soon as either the child or the parent modifies it, they become different entities stored at different memory locations (due to the copy-on-write mechanism).  In other words, neither the child nor the parent can "update" the variable in the other process. 

#!/usr/bin/perl -wl
use strict;

our $var = "foo";
# my $var = "foo";   # same thing wrt fork

sub modify_var {
    $var = shift;
}

unless (fork) {
    sleep 1;
    print "child: $var";
    modify_var("bar");
    print "child: $var";
} else {
    modify_var("baz");
    wait;
    print "parent: $var";
}

[download]

prints (as expected): 

child: foo
child: bar
parent: baz

[download]

As I'm reading your comment, you'd expect the output to be (?) 

child: baz
child: bar
parent: bar

[download]

As you can see, the variable is not shared.

In reply to Re^5: Defining global variable in a subroutine by Eliya
in thread Defining global variable in a subroutine by bihuboliya

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