$ perl -we 'fork || print for split //, "a" x 10'

when I run that on my computer, I get strange output.  Instead of 
printing "a" 2**10 times, the output contains random "1"'s, like this:

aa1aaaaa1aaa1aaaaa1aaa1aaaa1aaa1aaaaaa1aaaaa1aa1aaaaaa1a

etc..  I suspect this is due to a failing malloc() or something, but
It is silent failure.  Apparently similar commands don't output "a"s,
e.g.: 

$ perl -we 'for || print "a" for 1..10'

It also affects different computers differently; the "x 10" needs to
be replaced by a higher value to get the same effect sometimes (but not
too high, or you'll fork-bomb your computer).