Comments on: The Meaning of ‘su’ http://pthree.org/2009/12/31/the-meaning-of-su/ Linux. GNU. Freedom. Wed, 08 Feb 2012 02:59:26 +0000 hourly 1 http://wordpress.org/?v=3.4-alpha By: Why, fedora WHY!!!??? - Page 4 - Overclock.net - Overclocking.net http://pthree.org/2009/12/31/the-meaning-of-su/#comment-115525 Why, fedora WHY!!!??? - Page 4 - Overclock.net - Overclocking.net Wed, 09 Mar 2011 19:40:22 +0000 http://pthree.org/?p=1213#comment-115525 [...] with my built in console/python terminal, build tools, tabs, and sessions for anything. Noooooo http://pthree.org/2009/12/31/the-meaning-of-su/ It goes way back to the original Unix code and meanings. Originally SU was SuperUser and not [...] [...] with my built in console/python terminal, build tools, tabs, and sessions for anything. Noooooo http://pthree.org/2009/12/31/the-meaning-of-su/ It goes way back to the original Unix code and meanings. Originally SU was SuperUser and not [...]

]]> By: jonkx http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110933 jonkx Mon, 31 May 2010 17:22:42 +0000 http://pthree.org/?p=1213#comment-110933 I worked with the Unix OS from the early 1980's (at first we ran early versions on a DEC PDP-11) until 1992. Starting in 1992, I did contract work on proprietary versions based on SVR4. It was just easier to say the initials "S U" or "super-user" than to say "switch user" or "substitute user". To insist on correctness, whether authoritarian, historical or otherwise seems petty. Depending on the options used, su can be used to switch user, substitute user or become "super user". Success depends on knowledge of the appropriate password. "sudo" on the other hand may allow one to become any other user (depending on the configuration of sudo and being a "sodoer") knowing only the login password. On the systems I have used, a sudoer can become root ("super user") using this shell command at a terminal: sudo su - root and responding to the prompt with the login password used to sign in the current user. I think it is important to point out that you cannot become "super user" or root from a shell with the su command alone unless there is a root password and that password is entered at the prompt. I worked with the Unix OS from the early 1980′s (at first we ran early versions on a DEC PDP-11) until 1992. Starting in 1992, I did contract work on proprietary versions based on SVR4.

It was just easier to say the initials “S U” or “super-user” than to say “switch user” or “substitute user”. To insist on correctness, whether authoritarian, historical or otherwise seems petty.

Depending on the options used, su can be used to switch user, substitute user or become “super user”. Success depends on knowledge of the appropriate password. “sudo” on the other hand may allow one to become any other user (depending on the configuration of sudo and being a “sodoer”) knowing only the login password.

On the systems I have used, a sudoer can become root (“super user”) using this shell command at a terminal:

sudo su – root

and responding to the prompt with the login password used to sign in the current user.

I think it is important to point out that you cannot become “super user” or root from a shell with the su command alone unless there is a root password and that password is entered at the prompt.

]]> By: The (C) Gentoo User http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110757 The (C) Gentoo User Wed, 17 Mar 2010 16:58:53 +0000 http://pthree.org/?p=1213#comment-110757 Please fix the code. It does not compile with the latest GCC. Thanks. Please fix the code. It does not compile with the latest GCC. Thanks.

]]> By: Meanwhile in Gotham City ← pseudopost.org http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110737 Meanwhile in Gotham City ← pseudopost.org Sun, 07 Mar 2010 03:33:40 +0000 http://pthree.org/?p=1213#comment-110737 [...] Shared Aaron Toponce : The Meaning of ’su’. [...] [...] Shared Aaron Toponce : The Meaning of ’su’. [...]

]]> By: NetStorming » El significado de “su” http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110647 NetStorming » El significado de “su” Sun, 10 Jan 2010 04:40:48 +0000 http://pthree.org/?p=1213#comment-110647 [...] Al parecer, Aaron Toponce lo ha hecho en muchas oportunidades, llegando al punto de escribir un post sobre el significado de su. En el mismo comenta los distintos descubrimientos que evidenciaban diferentes significados para [...] [WORDPRESS HASHCASH] The comment's actual post text did not contain your blog url (http://pthree.org/2009/12/31/the-meaning-of-su) and so is spam. [...] Al parecer, Aaron Toponce lo ha hecho en muchas oportunidades, llegando al punto de escribir un post sobre el significado de su. En el mismo comenta los distintos descubrimientos que evidenciaban diferentes significados para [...]

[WORDPRESS HASHCASH] The comment’s actual post text did not contain your blog url (http://pthree.org/2009/12/31/the-meaning-of-su) and so is spam.

]]> By: Capt Caveman http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110580 Capt Caveman Sun, 03 Jan 2010 03:48:44 +0000 http://pthree.org/?p=1213#comment-110580 Back in the mid 70's when I learning to program my professor said su stood for super user and it that gave you the power to destroy an entire computer system with a single command. [WORDPRESS HASHCASH] The poster sent us '0 which is not a hashcash value. Back in the mid 70′s when I learning to program my professor said su stood for super user and it that gave you the power to destroy an entire computer system with a single command.

[WORDPRESS HASHCASH] The poster sent us ’0 which is not a hashcash value.

]]> By: Garry Parker http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110577 Garry Parker Fri, 01 Jan 2010 20:16:37 +0000 http://pthree.org/?p=1213#comment-110577 Aaron, you've got a point there! The more I think about, the more I tend to agree with you. If it was only used to become super-user, it's possible that's what the name originally meant. Perhaps later when more features were added, the definition changed. I've been using Unix since the late 80s and like you I've always heard that su meant super-user. Aaron, you’ve got a point there! The more I think about, the more I tend to agree with you. If it was only used to become super-user, it’s possible that’s what the name originally meant. Perhaps later when more features were added, the definition changed. I’ve been using Unix since the late 80s and like you I’ve always heard that su meant super-user.

]]> By: Aaron http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110576 Aaron Fri, 01 Jan 2010 08:00:38 +0000 http://pthree.org/?p=1213#comment-110576 @Garry Parker I would agree with you, except the code only allows switching to the root user. Switching to any other user wasn't possible like it is now. But again, it really doesn't matter what it stands for, does it? What matters is how you use it. @Garry Parker I would agree with you, except the code only allows switching to the root user. Switching to any other user wasn’t possible like it is now. But again, it really doesn’t matter what it stands for, does it? What matters is how you use it.

]]> By: Twitted by mehulved http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110575 Twitted by mehulved Fri, 01 Jan 2010 03:28:19 +0000 http://pthree.org/?p=1213#comment-110575 [...] This post was Twitted by mehulved [...] [WORDPRESS HASHCASH] The comment's server IP (94.23.51.159) doesn't match the comment's URL host IP (87.98.139.183) and so is spam. [...] This post was Twitted by mehulved [...]

[WORDPRESS HASHCASH] The comment’s server IP (94.23.51.159) doesn’t match the comment’s URL host IP (87.98.139.183) and so is spam.

]]> By: Links 1/1/2010: Many New GNU/Linux Releases, Ubuntu Tweak 0.5 | Boycott Novell http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110574 Links 1/1/2010: Many New GNU/Linux Releases, Ubuntu Tweak 0.5 | Boycott Novell Fri, 01 Jan 2010 03:07:39 +0000 http://pthree.org/?p=1213#comment-110574 [...] The Meaning of ’su’ [...] [...] The Meaning of ’su’ [...]

]]> By: Vadim P. http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110573 Vadim P. Fri, 01 Jan 2010 00:49:45 +0000 http://pthree.org/?p=1213#comment-110573 Interesting read. Interesting read.

]]> By: Garry Parker http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110572 Garry Parker Thu, 31 Dec 2009 23:02:04 +0000 http://pthree.org/?p=1213#comment-110572 I'm looking at volume 1 of the "UNIX Programmer's Manual, Revised and Expanded Version", published by Bell Laboratories, copywrite 1983, 1979 and according to this source, su means "substitue user id". Of course the C code you posted above predates that, but I think you might be misinterpreting the comment. The comment is merely saying the "substitute user id" command is used to become the "super-user" AKA root user. I’m looking at volume 1 of the “UNIX Programmer’s Manual, Revised and Expanded Version”, published by Bell Laboratories, copywrite 1983, 1979 and according to this source, su means “substitue user id”. Of course the C code you posted above predates that, but I think you might be misinterpreting the comment. The comment is merely saying the “substitute user id” command is used to become the “super-user” AKA root user.

]]> By: BUGabundo http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110571 BUGabundo Thu, 31 Dec 2009 19:45:40 +0000 http://pthree.org/?p=1213#comment-110571 Thanks for sharing. its a fun and nice reading [[]] Thanks for sharing.
its a fun and nice reading
[[]]

]]> By: Joseph Scott http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110570 Joseph Scott Thu, 31 Dec 2009 18:35:33 +0000 http://pthree.org/?p=1213#comment-110570 The FreeBSD man page - http://www.freebsd.org/cgi/man.cgi?query=su&apropos=0&sektion=0&manpath=FreeBSD+8.0-RELEASE&format=html - calls it "su -- substitute user identity". The history section at the bottom mentions: "A su command appeared in Version 1 AT&T UNIX." The man page for V3 - http://minnie.tuhs.org/UnixTree/V3/usr/man/man8/su.8.html - (dated 1/20/73) says: "su -- become privileged user" If there was a su command in V1 (which sounds likely) I wonder if it only supported switching to root. Perhaps the more generalized approach didn't come until later. There are some other interesting early Unix history bits in this paper - http://www.usenix.org/events/usenix09/tech/full_papers/toomey/toomey.pdf - not directly related to su, but an interesting read. Oh! More searching turned up this as well - http://code.google.com/p/unix-jun72/ - the scanned in codes from this - http://www.bitsavers.org/pdf/bellLabs/unix/PreliminaryUnixImplementationDocument_Jun72.pdf The FreeBSD man page – http://www.freebsd.org/cgi/man.cgi?query=su&apropos=0&sektion=0&manpath=FreeBSD+8.0-RELEASE&format=html – calls it “su — substitute user identity”.

The history section at the bottom mentions:

“A su command appeared in Version 1 AT&T UNIX.”

The man page for V3 – http://minnie.tuhs.org/UnixTree/V3/usr/man/man8/su.8.html – (dated 1/20/73) says:

“su — become privileged user”

If there was a su command in V1 (which sounds likely) I wonder if it only supported switching to root. Perhaps the more generalized approach didn’t come until later.

There are some other interesting early Unix history bits in this paper – http://www.usenix.org/events/usenix09/tech/full_papers/toomey/toomey.pdf – not directly related to su, but an interesting read.

Oh! More searching turned up this as well – http://code.google.com/p/unix-jun72/ – the scanned in codes from this – http://www.bitsavers.org/pdf/bellLabs/unix/PreliminaryUnixImplementationDocument_Jun72.pdf

]]> By: Aaron http://pthree.org/2009/12/31/the-meaning-of-su/#comment-110569 Aaron Thu, 31 Dec 2009 17:21:29 +0000 http://pthree.org/?p=1213#comment-110569 @Jensen I have no idea, but Ken Thompson said himself that if he were to rewrite the C programming language, creat() would be create(). @kragil You didn't read the post, at least not all the way through, did you? You might want to do that before commenting. @Jensen I have no idea, but Ken Thompson said himself that if he were to rewrite the C programming language, creat() would be create().

@kragil You didn’t read the post, at least not all the way through, did you? You might want to do that before commenting.

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