Talk:User identifier

This is the talk page for discussing improvements to the User identifier article.
This is not a forum for general discussion of the article's subject.

Put new text under old text. Click here to start a new topic.
New to Wikipedia? Welcome! Learn to edit; get help.

Article policies

Find sources: Google (books · news · scholar · free images · WP refs) · FENS · JSTOR · TWL

Computing Low‑importance

	This article is within the scope of WikiProject Computing, a collaborative effort to improve the coverage of computers, computing, and information technology on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.ComputingWikipedia:WikiProject ComputingTemplate:WikiProject ComputingComputing articles
Low	This article has been rated as Low-importance on the project's importance scale.

Linux Low‑importance

	Linux portal This article is within the scope of WikiProject Linux, a collaborative effort to improve the coverage of Linux on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.LinuxWikipedia:WikiProject LinuxTemplate:WikiProject LinuxLinux articles
Low	This article has been rated as Low-importance on the project's importance scale.

Shadow does not store numeric IDs[edit]

The UID value references users in the /etc/passwd file. Shadow password files and Network Information Service also refer to numeric UIDs.

This is not accurate enough, because /etc/shadow does not store numeric UIDs, only the username (and password information).

I'm not sure if "Shadow password files" does mean passwd AND shadow, or only shadow. --CrazyTerabyte 19:22, 3 July 2006 (UTC)[reply]

tools?[edit]

It would sure be nice here to have a simple example command of how to retrieve UID/usernames in various linux/unix shells.. —Preceding unsigned comment added by 217.56.230.234 (talk) 08:47, 3 September 2007 (UTC)[reply]

Nobody[edit]

I dispute that 32767 is "the most-commonly value used for 'nobody'".

The "nobody" user was added when NFS was introduced, as a surrogate for the root user.

Back then, the corresponding numeric UID was 65534 or 4294967294, depending on whether the underlying uid_t type was 16 or 32 bit. These values both correspond to -2 (negative two) after conversion to an "unsigned int" type.

The value -2 was chosen because the usual manner of indicating errors was to return -1, while the usual manner of checking for errors was simply to check for any negative; hence a naive check would say "no such user", while a more sophisticated check would say "nobody".

Sometimes, particularly with System-V derived systems, the numeric value for "nobody" was often forced to meet normal UID allocation policy; hence other outlier values such as 32767 were chosen.

Linux distributions generally followed the earlier BSD policy, but mistakenly continued to use 65534 on kernels with 32-bit UID support.

Martin Kealey (talk) 03:40, 10 September 2013 (UTC)[reply]

Expand Special values section with low-uid users?[edit]

Maybe I'm alone in this, but I feel we need historical and current info covering the low-uid users and groups (bin, daemon, adm, lp, sys, et al.) under User_identifier#Special_values. Each one could be an entire research project in itself, so I'm wary of contributing original research. Thoughts? --Rfsmit (talk) 18:37, 23 January 2020 (UTC)[reply]