Hey, what about SIGIO?

[Edward Luke]

In signal.h there is a signal defined as:
#define        SIGIO   23      /* input/output possible signal */


I have an application that will be doing computations, asynchronously
with this I would like to get a signal when new data arrives on an
input file descriptor, or when an output file descriptor is free to be
filled again.  Is it possible for me to do this without using fork()
to start another process to monitor the file descriptor?  Can I tell
the OS to give me a SIGIO when there is a pending condition on a
socket?  Just what is the SIGIO signal for?

Edward Luke
Mississippi State University
NSF Engineering Research Center for Complex Field Simulations