dwp@mtune.ATT.COM (David Preisler) (10/28/89)
Problem: /----- | | On a 3b2 700 under sVr3 I've got GNU Emacs 18.54 built [ HAVE_PTY defined ], | but I find that it does not work properly through a DataKit VC. I do find | however, that when run through a direct port it appears to work properly. | | Symptoms: The screen opens up correctly, but typed chars do not appear on | the screen. Ctrl chars are also generally ignored. Emacs will beep at ^g | and ^z, and occasionally it will produce the unsupported operation message | ( autosave, abort- core dump ). | | \----- SOLUTION: +------ | | Date: Fri, 27 Oct 89 19:52:41 EDT | From: Jonathan Simon Kay <@JHMAIL.HCF.JHU.EDU:kay@JHUNIX.BITNET> | Subject: Emacs pty problems | To: dwp@mtune.ATT.COM | | | Simple. It's a bug in the pty device driver. Seems the master end of | the ptys don't support nonblocking I/O. So emacs is blocked - it only | responds to characters bound to signals in the tty (that's why ^G | produces a response). The easiest fix is to give up on ptys. If you | really want 'em, I'll send you my workaround code. What it does is | starts up a whole new process that does the waiting instead of emacs | and sends what it gets to emacs via a pipe, which does support | nonblocking I/O. Very inefficient and kinda slow, but it does work. | | | Jon Kay +----- Thanks, david The Distributed Programming Tools Group: "Don't Panic!"