Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sol.ctr.columbia.edu!lll-winken!iggy.GW.Vitalink.COM!widener!netnews.upenn.edu!pender.ee.upenn.edu!chip From: chip@pender.ee.upenn.edu (Charles H. Buchholtz) Newsgroups: comp.unix.admin Subject: SUMMARY: Background processes writing to other people's ptys Message-ID: <42938@netnews.upenn.edu> Date: 10 May 91 17:02:29 GMT References: <42399@netnews.upenn.edu> Sender: news@netnews.upenn.edu Reply-To: chip@pender.ee.upenn.edu (Charles H. Buchholtz) Organization: University of Pennsylvania Lines: 41 Nntp-Posting-Host: pender.ee.upenn.edu Here's the original question: >I run a few multi-user machines running SunOS 4.1. Our users login >via telnet and rlogin. Frequently, the following problem occurs: > >Arnold logs in on ptyp1, starts a long running job, puts it in >background (via ^Z bg), and then logs out. "ps" shows "?" as the >process' tty. > >Betty logs in on ptyp1, and sees the output of Arnold's background >process on her display mixed in along with her session. > >What I want is: > >Some way to cause such processes to abort as soon as they try to write >to the pty, or failing that, some way to cause the processes to block >when they try to write to the pty. > >I can't count on the users to do anything; I need a system wide >solution. A Sun Patch number or "fixed in 4.1.1" is an acceptable >solution. I got the answer I was looking for from hr@sirius.astro.uiuc.edu (Harold Ravlin). He pointed me to the CERT advisory concerning Sun telnet, and Sun patch 100125-03. Many people suggested using "ofiles" to determine which process was using that pty. Thanks to all those who responded: Harold Ravlin Pat Barron Henry Clark Lyle Seaman Gary Mills Charles H. Buchholtz chip@ee.upenn.edu Systems Programmer (215) 898-2491 School of Engineering and Applied Science 200 S. 33rd St, rm 154 University of Pennsylvania Philadelphia, PA 19104