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Luisa Donato

How old were you when you found out that /usr stands for Unix System Resources and not for user?

8 Jun 2023 at 21:19 | Open on hachyderm.io
126 comments
No Fun Berg

@Luisa_Donato Today. I always wondered, but never enough to look it up. Thanks!

12 Jun 2023 at 21:56 | Open on mastodon.world
Joe G

@Luisa_Donato @FreakyFwoof 44! Seriously, I had no idea until I just now read it. Lol.

13 Jun 2023 at 5:00 | Open on tweesecake.social
Georg
lj·rk

@Luisa_Donato It doesn't! To quote "The UNIX Programming Environment" (archive.org/details/UnixProgra) by BWK and Rob Pike:

> _(user is abbreviated to usr in the same spirit as cmp, Is, etc.) /usr/you is your login directory, your current directory when you first log in._

(p. 48)

and

> _/usr is called the “user file system,” although it may have little to do with the actual users of the system. On our machine, our login directories are /usr/bwk and /usr/rob, but on your machine the /usr part might be dif ferent,[...]_

(p. 65)

There's another interesting paragraph following it:

> _Just as in /, there are directories called /usr/bin, /usr/lib and /usr/tmp. These directories have functions similar to their namesakes in /, but contain programs less critical to the system. For example, nroff is usually in /usr/bin rather than /bin, and the FORTRAN compiler libraries live in /usr/lib. Of course, just what is deemed “critical” varies from system to system. Some systems, such as the
distributed 7th Edition, have all the programs in /bin and do away with /usr/bin altogether; others split /usr/bin into two directories according to frequency of use. _

@Luisa_Donato It doesn't! To quote "The UNIX Programming Environment" (archive.org/details/UnixProgra) by BWK and Rob Pike:

> _(user is abbreviated to usr in the same spirit as cmp, Is, etc.) /usr/you is your login directory, your current directory when you first log in._

(p. 48)

14 Jun 2023 at 17:35 | Open on todon.eu
lj·rk

@Luisa_Donato
To give a bit of history: The user file system`/usr` was indeed used for home directories but on a separate disk, namely `/dev/rp01`, while the rest of the *root* file system resided on `/dev/rp00`. The latter was a faster and smaller disk which contained the system, the second disk was added once it was full and the user home directories moved to it. In UNIX V3, there were too many binaries in `/bin` to store on the fast disk, less crucial binaries were stored in a special "user directory" for those binaries, called `/usr/bin` (also, some of them where simply stored in the developer's directory, so you had a bunch of `/usr/dmr/ls` or the like. This practice of splitting crucial from non-curcial binaries, only born out of disk space got standardized. On most modern UNIX and alike systems, the initial boot happens through something like Linux' initial RAM file system, thus completely removing the need for having "crucial" binaries separate. Which is why most Linux distros move or moved to merge everything (for some reason they merged it into `/usr` instead of getting rid of it, like UNIX V7 from '79, don't ask me why). At some point people startet calling it "UNIX System Resources" as a "post hoc backronym".

Also cf. DMR's "UNIX Notes" bell-labs.com/usr/dmr/www/note

@Luisa_Donato
To give a bit of history: The user file system`/usr` was indeed used for home directories but on a separate disk, namely `/dev/rp01`, while the rest of the *root* file system resided on `/dev/rp00`. The latter was a faster and smaller disk which contained the system, the second disk was added once it was full and the user home directories moved to it. In UNIX V3, there were too many binaries in `/bin` to store on the fast disk, less crucial binaries were stored in a special "user directory"...

14 Jun 2023 at 17:35 | Open on todon.eu
andrei!
DELETED

@Luisa_Donato @smallsco Source? Because /usr is where user files used to be. The reason we have /usr/bin etc is because the hard drive of / was full.

15 Jun 2023 at 18:52 | Open on mstdn.io
Scott Small

@js @Luisa_Donato From what I’ve read it was originally for user files, but when those later got moved to /home, a backronym was created for its’ new purpose. tldp.org/LDP/Linux-Filesystem-

Although some say “User System Resources” others say “Unix Shared Resources”, it doesn’t seem like there’s one clear backronym.

15 Jun 2023 at 19:03 | Open on oldbytes.space
FluffyPuppyKasey
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