C:\>type test.pl
# grab the first ENV var name we find
for ( keys %ENV ) { $key = $_; last; }
# reset ENV var
print "Resetting $key, was $ENV{$key}\n";
$ENV{$key} = 'new value';
# fork
my $pid = fork();
# confess
print $pid ? "Parent has $key:$ENV{$key}\n" : "Child has $key:$ENV{$key}\n";


C:\>perl test.pl
Resetting PROMPT, was $P$G
Parent has PROMPT:new value
Child has PROMPT:new value

C:\>

##</code><code>##

[root@www root]# cat test.pl
# grab the first ENV var name we find
for ( keys %ENV ) { $key = $_; last; }
# reset ENV var
print "Resetting $key, was $ENV{$key}\n";
$ENV{$key} = 'new value';
# fork
my $pid = fork();
# confess
print $pid ? "Parent has $key:$ENV{$key}\n" : "Child has $key:$ENV{$key}\n";

[root@www root]# perl test.pl
Resetting _, was /usr/bin/perl
Parent has _:new value
Child has _:new value
[root@www root]#