Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!uakari.primate.wisc.edu!samsung!munnari.oz.au!ariel!ucsvc.ucs.unimelb.edu.au!wehi!baxter_a From: BAXTER_A@wehi.dn.mu.oz Newsgroups: comp.sys.amiga.tech Subject: Setting priority for 2 interacting programs Message-ID: <16666@wehi.dn.mu.oz> Date: 26 Nov 90 12:14:46 GMT Organization: Walter & Eliza Hall Institute Lines: 22 PROBLEM: Program A spools a file to disk and execute()s a command to type the file to a device which prints it after some processing. Program A runs at priority 0, device runs at priority 5. Device hoggs processor, and Program A does bugger all, making the spool fairly useless. Thus Program A at priority 0, device at priority 0. Works fine, except now, if Program A tries to write direct to device with fprintf() calls, the system hangs (or seems to, I got bored). This does _not_ happen if device priority is set to 5. Note, I do not check the return code from fprintf(). Should I? What's wrong with this? How do I get the two programs to talk to each other politely without stepping on each others toes? Regards Alan