Re: ed

From	cross@spitfire.i.gajendra.net (Dan Cross)
Newsgroups	comp.unix.shell
Subject	Re: ed
Date	2026-06-10 23:53 +0000
Organization	PANIX Public Access Internet and UNIX, NYC
Message-ID	<110ctda$kkq$1@reader1.panix.com> (permalink)
References	<slrn112c9fb.2pa2.zaydm@new.localdomain> <110abmr$ckmk$12@dont-email.me> <110cmrj$32trj$1@dont-email.me> <110csrb$13aa9$2@kst.eternal-september.org>

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In article <110csrb$13aa9$2@kst.eternal-september.org>,
Keith Thompson  <Keith.S.Thompson+u@gmail.com> wrote:
>John McCue <jmclnx@gmail.com.invalid> writes:
>> Lawrence D?Oliveiro <ldo@nz.invalid> 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.
>>
>> 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.
>>
>> 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.
>
>That's not what it means.
>
>Historically, /bin and /usr/bin were two different directories,
>with /bin containing only executables that are needed during
>system startup.  /usr/bin can be on a separate filesystem that isn't
>initially mounted.  I think /usr was also where home directories were
>located; for example, Dennis Ritchie's home directory was /usr/dmr.
>
>I think the origin of that is an early PDP-11 or PDP-7 system at
>Bell Labs that had limited space on its main hard drive a larger
>secondary drive.

That's about right.  Btw, it was the -11; the organization of
the filesystem on PDP-7 Unix was very different.

>NetBSD 10.1, the latest release, retains that distinction.  I have
>it running in a VM, and it has 39 files in /bin and 515 in /usr/bin.
>All the executables are dynamically linked, but I think they
>depend on on libraries in /lib, not /usr/lib.  /bin and /usr/bin
>are on the same filesystem (though I think it can be configured
>with /usr in its own filesystem).
>
>Many other Unix-like systems have transitioned to making /bin a
>symbolic link to /usr/bin.  But remnants of the old layout still
>exist; for example /usr/bin and /bin are typically both in $PATH
>even if they're the same directory.
>
>Similar things apply to /lib and /usr/bin, and to /sbin and
>/usr/sbin.

Yup.  I usually just make one big filesystem on most machines.
There isn't much reason to split them up anymore.  Back in the
day, partition sizes were hardcoded and compiled into the
drivers for the different disk devices; you carefully chose how
you used each disk and which partitions you created filesystems
on.  BSD fixed that with disklabels; many commercial Unixes
similiarly with their own proprietary versions.  Now it is du
jour.

	- Dan C.

Thread

ed __ ___ ________ ____ ______. Zayd Mohammed <zaydm@172.24.208.1> - 2026-06-08 02:16 +0000
  Re: ed __ ___ ________ ____ ______. Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-06-08 04:46 +0200
    Re: ed __ ___ ________ ____ ______. cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-08 13:44 +0000
      Re: ed __ ___ ________ ____ ______. gazelle@shell.xmission.com (Kenny McCormack) - 2026-06-08 14:12 +0000
        Re: ed. cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-08 19:30 +0000
      Re: ed __ ___ ________ ____ ______. Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-06-08 14:40 -0700
        Re: ed __ ___ ________ ____ ______. groenveld@acm.org (John D Groenveld) - 2026-06-09 00:04 +0000
        Re: ed __ ___ ________ ____ ______. Adam Sampson <ats@offog.org> - 2026-06-09 01:50 +0100
        Re: ed __ ___ ________ ____ ______. Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-06-09 16:47 +0200
          Re: ed __ ___ ________ ____ ______. Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-06-09 16:41 -0700
      Re: ed __ ___ ________ ____ ______. Ben Collver <bencollver@tilde.pink> - 2026-06-09 14:27 +0000
    Re: ed __ ___ ________ ____ ______. Eric Pozharski <apple.universe@posteo.net> - 2026-06-08 22:28 +0000
    Re: ed __ ___ ________ ____ ______. Lumin Etherlight <lumin+usenet@etherlight.link> - 2026-06-09 03:25 +0300
      Re: ed __ ___ ________ ____ ______. Daniel Cerqueira <dan.list@lispclub.com> - 2026-06-09 09:47 +0100
        Re: ed __ ___ ________ ____ ______. Joerg Mertens <joerg-mertens@t-online.de> - 2026-06-09 15:53 +0200
          Re: ed __ ___ ________ ____ ______. Daniel Cerqueira <dan.list@lispclub.com> - 2026-06-09 21:00 +0100
          Re: ed __ ___ ________ ____ ______. Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-06-09 16:29 -0700
            Re: ed __ ___ ________ ____ ______. Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-06-11 08:39 +0200
              Re: ed __ ___ ________ ____ ______. Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-06-11 13:40 -0700
                Re: ed __ ___ ________ ____ ______. Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-06-12 16:56 +0200
                Re: ed __ ___ ________ ____ ______. Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-06-12 15:22 -0700
                Re: ed __ ___ ________ ____ ______. Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-06-13 00:58 +0200
      Re: ed __ ___ ________ ____ ______. Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-06-09 17:57 +0200
  Re: ed __ ___ ________ ____ ______. John McCue <jmclnx@gmail.com.invalid> - 2026-06-08 22:57 +0000
  Re: ed __ ___ ________ ____ ______. Lumin Etherlight <lumin+usenet@etherlight.link> - 2026-06-09 03:02 +0300
  Re: ed __ ___ ________ ____ ______. gmc@metro.cx (Koen Martens) - 2026-06-09 06:17 +0000
    Re: ed __ ___ ________ ____ ______. Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-09 06:55 +0000
    Re: ed __ ___ ________ ____ ______. John McCue <jmclnx@gmail.com.invalid> - 2026-06-09 19:44 +0000
      Re: ed __ ___ ________ ____ ______. Top Dead Ctr <tdc@invalid.invalid> - 2026-06-09 14:09 -0600
      Re: ed __ ___ ________ ____ ______. Christian Weisgerber <naddy@mips.inka.de> - 2026-06-09 23:52 +0000
        Re: ed Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-10 00:40 +0000
      Re: ed Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-10 00:38 +0000
        Re: ed John McCue <jmclnx@gmail.com.invalid> - 2026-06-10 22:01 +0000
          Re: ed Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-06-10 16:43 -0700
            Re: ed Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-06-10 16:50 -0700
            Re: ed cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-10 23:53 +0000
              Re: ed Eli the Bearded <*@eli.users.panix.com> - 2026-06-11 00:12 +0000
                Re: ed Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-11 00:55 +0000
                Re: ed cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-11 02:00 +0000
                Re: ed Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2026-06-10 19:30 -0700
                Re: ed cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-11 11:31 +0000
                Re: ed Christian Weisgerber <naddy@mips.inka.de> - 2026-06-11 15:02 +0000
              Re: ed Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-06-11 08:46 +0200
            Re: ed John McCue <jmclnx@gmail.com.invalid> - 2026-06-11 14:28 +0000
          Re: ed cross@spitfire.i.gajendra.net (Dan Cross) - 2026-06-10 23:48 +0000
          Re: ed Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2026-06-11 00:24 +0000
            Re: ed John McCue <jmclnx@gmail.com.invalid> - 2026-06-11 14:11 +0000
              Re: ed Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-12 00:22 +0000
          Re: ed Lawrence D’Oliveiro <ldo@nz.invalid> - 2026-06-11 00:53 +0000
            Re: ed Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-06-11 09:02 +0200
    Re: ed __ ___ ________ ____ ______. Nuno Silva <nunojsilva@invalid.invalid> - 2026-06-10 11:03 +0100
      Re: ed __ ___ ________ ____ ______. Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2026-06-11 09:12 +0200
        Re: ed __ ___ ________ ____ ______. Nuno Silva <nunojsilva@invalid.invalid> - 2026-06-12 09:44 +0100
          Android editor (Was: ed __ ___ ________ ____ ______.) gazelle@shell.xmission.com (Kenny McCormack) - 2026-06-12 09:03 +0000
            Re: Android editor Nuno Silva <nunojsilva@invalid.invalid> - 2026-06-12 12:01 +0100

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