Path: csiph.com!weretis.net!feeder9.news.weretis.net!panix!.POSTED.spitfire.i.gajendra.net!not-for-mail From: cross@spitfire.i.gajendra.net (Dan Cross) Newsgroups: comp.unix.shell Subject: Re: ed Date: Wed, 10 Jun 2026 23:48:46 -0000 (UTC) Organization: PANIX Public Access Internet and UNIX, NYC Message-ID: <110ct4u$n7d$1@reader1.panix.com> References: <1109qej$2vlaa$1@dont-email.me> <110abmr$ckmk$12@dont-email.me> <110cmrj$32trj$1@dont-email.me> Injection-Date: Wed, 10 Jun 2026 23:48:46 -0000 (UTC) Injection-Info: reader1.panix.com; posting-host="spitfire.i.gajendra.net:166.84.136.80"; logging-data="23789"; mail-complaints-to="abuse@panix.com" X-Newsreader: trn 4.0-test77 (Sep 1, 2010) Originator: cross@spitfire.i.gajendra.net (Dan Cross) Xref: csiph.com comp.unix.shell:26881 In article <110cmrj$32trj$1@dont-email.me>, John McCue wrote: >Lawrence D?Oliveiro wrote: >> On Tue, 9 Jun 2026 19:44:19 -0000 (UTC), John McCue wrote: >> >>> There is one use for ed(1), when I boot NetBSD into single user >>> mode, ed(1) is the only one available without jumping through hoops. >> >> Why is that? Is it because NetBSD still has the legacy root-versus-usr >> separation of executables and libraries? > >From what I have seen, seems Linux does not have a real single >user mode. But I think that is OK for Linux. Hmm, boot with `init=/bin/sh` is probably pretty close. >NetBSD and the other BSDs have real single user mode where no >file systems are mounted, no daemons are started and root is >mounted RO. NetBSD boots into /bin/sh or a shell of your >choice and you work from that, no login needed. Also I think >only static executables are available for use. Dynamic executables can be used, provided the shared objects are available. "Single user mode" really just means that the full boot sequence hasn't run and a shell got started on the console; it doesn't change much else (all of the mounting of filesystems and so on happens in a startup script).. >I do not know what "legacy root-versus-usr" means, I would >never want a system that does not have a clear separation >between root and users. Lawrence is a known troll. I'm sure he's referring to the split between `/bin` and `/usr/bin` etc. Ie, why have some things on the root filesystem (`/bin`) and others in the `/usr` filesystem (`/usr/bin`). There is an answer; it's historical. `/usr` is actually the _user_ filesystem; that's where home directories went. And there was more space on that device than on the device that contained `/`, so `/usr/bin` was born for binaries that were too big to fit on `/bin`. Several systems have more or less done away with the split, now that disk is plentiful. Linux and Solaris spring to mind; others keep the split for organizational purposes. It doesn't really say anything about a system, however, beyond what aesthetics its users and maintainers subscribe to. - Dan C.