polling streams

[straz@cambridge.apple.com (Steve Strassmann)]

 >To: info-mcl@ministry.cambridge.apple.com
 >From: chaput@ils.nwu.edu (Cliff Chaput)
 >Newsgroups: comp.lang.lisp.mcl
 >Subject: polling streams
 >Followup-To: comp.lang.lisp.mcl
 >Date: 8 Jun 1993 19:36:04 GMT
 >Organization: Institute for the Learning Sciences, Northwestern University
 >Distribution: world
 >Nntp-Posting-Host: chaput.ils.nwu.edu
 >
 >I'm using a the tcp-stream from the mcl library, and I'd like to display
 >the output I get whenever there is new output to get.  Is there any way to
 >know if there is any output to get off the stream so that I don't hang my
 >program when I read something?
 >
 >thanks
 >cliff
 >
 >Cliff Chaput                   | "The scribes on all the people shove
 >Institute of Learning Sciences |  and bawl allegiance to the state.
 >Northwestern University        |  But they who love the greater love
 >chaput@ils.nwu.edu             |  lay down their lives; they do not hate"
 >

The Common Lisp function LISTEN is used to poll a stream.