Hello Gert, Good question.
What we discovered during an upgrade of our OpenWRT distribution (from a fairly old one, I cannot exactly recall the version, I do recall it was running kernel 2.6.22), was that suddenly our curses application did not start anymore. And yes, for historical reasons, it was executed from the inittab, no argument there. I was looking into the reason and typing an answer to you, but I have to look a little better as to the why. If you don't mind, I will get back to you on Monday. Kind regards, Michel Stam -----Original Message----- From: Gert Doering [mailto:g...@greenie.muc.de] Sent: Friday, October 03, 2014 16:16 PM To: Stam, Michel [FINT] Cc: openwrt-devel@lists.openwrt.org Subject: Re: [OpenWrt-Devel] [PATCH procd 3/8] Fix curses applications to work with procd Hi, On Thu, Oct 02, 2014 at 02:56:18PM +0200, Michel Stam wrote: > The problem was caused by procd not opening /dev/tty* (which ever was > specified in /etc/inittab), causing /proc/PID/fd to point to /console > instead. /dev/console is a non-controlling tty (CTTY), and cannot be > used as one, which is exactly what curses applications want. Since > this is very likely to cause problems with other programs, procd now > opens /dev/tty? when the ID field of the inittab assigns one, and forces this to be a CTTY. I won't claim to understand the OpenWRT intricacies here, so take this with a grain of salt. In traditional unix systems, setting up a tty and acquiring a controlling tty is getty's job, and not that of the init system - and init should not start interactive programs (or "possibly interactive programs") from /etc/inittab. Changing this is fairly invasive into the way the system works and what programs can expect regarding signal delivery etc. - like, someone pressing ctrl-c on a tty, and a background process being started on that tty will get a SIGINT (while it normally wouldn't). Genuinely curious: can you explain a bit better in which cases this change would be needed and/or beneficial? thanks, gert -- USENET is *not* the non-clickable part of WWW! //www.muc.de/~gert/ Gert Doering - Munich, Germany g...@greenie.muc.de fax: +49-89-35655025 g...@net.informatik.tu-muenchen.de _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
