in reply to adding non printable characters in perl's print function

A quick way to check your output to see everything you put in comes out is to use the 'od' command (on any unix-like box):

perl -e 'print ":Hello ^M world:\n"' | od -c

This will give you

0000000   :   H   e   l   l   o      \r       w   o   r   l   d   :  \n

--
Lyon