laser-lovers@ucbvax.UUCP (01/10/86)
----------------------------- Has anyone else written a LaserWriter server for the Multi-Device Queuing System (by Doug Kingston at Ballistic Research Labs)? I have the server functioning pretty well: it invokes the appropriate filter(s) as supplied by Adobe, based on an extended argument that specifies the type of document being queued. The problem that has really got me stumped is that I can't hear anything on the status channel back from the LaserWriter, while I'm running MDQS. I have a diagnostic program (based on code borrowed from psif.c) that I use to make sure the hardware is talking OK (we DID have a problem with a dead line from printer back to computer, but alas! that is fixed and can't be blamed any more). The program sets up two processes; the parent sends a control-T to stdout to request a status report, and the child listens on a dup of stdout and gets the status. It works great. Basically the exact same code is in my server, and the child never hears anything, but exits after seeing EOF. My suspicion is that there may be something in the way MDQS handles the file descriptors before the server even enters the picture, which might be causing my problem. Except . . . the child's fdopen() for reading on the dup of stdout returns a valid stream pointer. If anybody has any ideas (even long shots!?), or if there's a better way to do this, please get in touch. Thanks much! - Susan Richter richter@rand-unix.ARPA ...!decvax!philabs!ttidca!randvax!richter ...!ihnp4!wlbr!trwrb!randvax!richter