in reply to undef var

B::Deparse is your friend (although it really doesn't reveal too much with these one-liners): 
$ perl -MO=Deparse -e 'print (my ($rec) = undef);'

print my($rec) = undef;
-e syntax OK


$ perl -MO=Deparse -e 'print "return=" . (my ($rec) = undef);'

print 'return=' . (my($rec) = undef);
-e syntax OK

[download]
The first one-liner is printing the result of assigning undef to $rec and the second appends that result to a string.

UPDATE:
Nope ... i wasn't quite correct on this one. Thanks for clearing things up sgifford and tye.

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

In Section Seekers of Perl Wisdom