Mulitple I/O streams

I am writing a UNIX shell and I'm having some problems writing the scripting component.... acts just like the POSIX script command. Ok, so here's my question is it possible to, say, create a new process that uses multiple I/O streams. What I need is one stream to output to the console and another stream to output the same to a file. Is this possible?... or should I create one process and redirect its output to the file, then create the same again process and output to the console?... any thoughts?

What OS?

gg

At home i'm using Red Hat 8.0... but the target system is IRIX 6

Yea... tee will work just fine. Thx for the info