Path: utzoo!utgpu!watmath!clyde!att!chinet!les From: les@chinet.chi.il.us (Leslie Mikesell) Newsgroups: comp.unix.questions Subject: Re: signals to running processes Message-ID: <7045@chinet.chi.il.us> Date: 1 Dec 88 18:50:33 GMT References: <950@taux01.UUCP> Reply-To: les@chinet.chi.il.us (Leslie Mikesell) Organization: Chinet - Public Access Unix Lines: 18 In article <950@taux01.UUCP> cjosta@taux01.UUCP (Jonathan Sweedler) writes: >2) Or, is there another way for a random user to cause a program to >asynchronously print out a status report (or perform some action) once >it has started running? If you are running SysV you can have the program fork off a process that creates a FIFO with appropriate write permissions and blocks waiting for someone to write a command to it. When it reads a command it would send a signal to its parent. You might also set up a pipe from the child to the parent so that the details of the command could be passed (such as the device or another FIFO name to send the progress report to). If response doesn't have to be instant, the main process could periodically do a non-blocking read on the FIFO instead of using a child process. I suppose that something similar is possible with sockets under BSD. Les Mikesell