General :: Able To Write On Stdout But Not In A File

I want to keep a trace of the URL I visit, so I use a command line like this:

tcpdump -ien1 -v -X 'tcp port 80' | sed -nl
's/^.0x[0-9a-f]{4}:.{43}(.)$/1/p' |perl break.pl |perl -pe
's/(GET|POST).(.*?).HTTP/1....Host:.([a-zA-Z._0-9-]*)../"
BEGURL

[Code]....

I also tried redirecting stdout and stderr to /tmp/out, it's still empty. The file has write access. I have no idea what it can be. Is there anything else than stdout and stderr?