Here is my code

what you forgot to say was that you've simply copied this code from this site, where there's an article written by David Chan, on April 20, 2001 (over 5 years ago!), which says:

$ 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 no
+t
too high, or you'll fork-bomb your computer).
[download]

For more on the code-copying habits of this poster, see this node.