Subject: Re: Splitting / and /usr
To: Alistair G. Crooks <>
From: Robert Elz <kre@munnari.OZ.AU>
List: current-users
Date: 04/13/2000 10:36:15
    Date:        Wed, 12 Apr 2000 01:31:41 -0700 (PDT)
    From:        "Alistair G. Crooks" <>
    Message-ID:  <>

  | [Off topic warning]

Ditto - but recording history sometimes has its uses...

  | I believe that the topic of splitting / and /usr was discussed
  | at the Glasgow University meeting of the UKUUG, which was around
  | 1978,

It was definitely done before that.

Unfortunately, I can't find a 5th edition manual (or even a reprinted
facsimilie thereof at the minute), but the 6th edition manual for sh(1)
says ...

	If the first argument [ on a command line ] is the name of an
	executable file, it is invoked; otherwise the string `/bin' is
	prepended to the argument.  (In this way most standard commands,
	which reside in `/bin', are found.)  If no such command is found,
	the string `/usr' is further prepended (to give `/usr/bin/command')
	and another attempt is made to execute the resulting file.  (Certain
	lesser-used commands live in `/usr/bin'.)

The sixth edition manual is dated May 75, but the date on the sh man page
is 5/15/74 (which I interpret as the 15th of May, 1974).

For those who are new to unix (within the last 20 years) note that there
was no notion of a user settable path...

  | I don't have my copy of the CACM paper to hand, so I can't
  | check dates.

I have checked now, and it says nothing either way, so that is no help.
Kernighan's "Unix for Beginners" (of a generally similar vintage) gives
a diagrammatic view of the filesystem tree, in which all that exists in
/usr are user directories, though that is not really conclusive.

  | I suspect that Alistair Kilgour or Zdravko Podolski could provide
  | more information, or any of the Bell Labs alumni who were there.

I will see if Dennis will tell me...