Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: Notesfiles; site uokvax.UUCP Path: utzoo!watmath!clyde!floyd!vax135!houxz!houxm!ihnp4!inuxc!pur-ee!uiucdcs!uokvax!jab From: jab@uokvax.UUCP Newsgroups: net.unix Subject: Re: job control in Sys V - (nf) Message-ID: <6100034@uokvax.UUCP> Date: Mon, 18-Jun-84 20:43:00 EDT Article-I.D.: uokvax.6100034 Posted: Mon Jun 18 20:43:00 1984 Date-Received: Fri, 22-Jun-84 05:48:25 EDT References: <827@sri-arpa.UUCP> Lines: 49 Nf-ID: #R:sri-arpa:-82700:uokvax:6100034:004:1637 Nf-From: uokvax!jab Jun 18 19:43:00 1984 #R:sri-arpa:-82700:uokvax:6100034:004:1637 uokvax!jab Jun 18 19:43:00 1984 /***** uokvax:net.unix / sri-arpa!ARPA / 10:11 pm Jun 14, 1984 */ From: Preston MullenI keep seeing hints that System V (perhaps only release 2?) has some form of job control. Could someone elaborate on this and compare it with 4.2bsd job control? I am especially interested in job control at the user command (shell) level, not capabilities that are only implemented in system calls. /* ---------- */ I'll tell you about it, with a quick disclaimer: I'll provide you with facts (not a rave about how good it is, or a flame about how bad it is) and let you for your own opinions. System V Release 2.0 has a utility called "shell layers", named after the "layers" program that runs on the Teletype 5620 terminal and implements windows on the dot-mapped-display screen. "shell layers" is best thought of as a "virtual terminal" facility, although it isn't as complete as the Purdue "pseudo-tty" driver. You are given the ability to run up to seven virtual terminals (each with its own /dev entry), and switch between them via a magic character, which is usually ^Z. For example, % shl >>> create layer1 layer1 (PS1 is set to the layer name) layer1 ls (output from ls) layer1 ^Z >>> create layer2 layer2 cd / layer2 ^Z >>> resume layer1 (resuming layer1) layer1 You get the gist. The magic differences from the "job control" you see now is that ^Z takes you to a "manager", not to a shell, and that the programs in each "virtual terminal" don't know that they're running in a layer. Let's not get into a discussion on whether this is a good or bad implementation. Jeff Bowles Lisle, IL