Number in man page titles e.g. sleep(3)

LtWorf

Step 1: Read `man man` Step 2: Feel the urge to write an article about that

amelius

Confession. I think I haven't read manpages since stackoverflow and certainly not since LLMs. Perhaps the modern version of "man" should be a program you can talk to.

kykat

I looked up what the numbers mean a couple of times, but always forget it immediately

mjlee

If you like man trivia (and why else would you be reading this?) you could check out the top comment at https://unix.stackexchange.com/questions/405783/why-does-man... (discussed at https://news.ycombinator.com/item?id=27994194 )

gerikson

> (... less common section numbers) One very important section number is 5 - it's for file formats. So if you forget the crontab format, you need to invoke `man 5 crontab` to read about it.

PhilipRoman

Interestingly, the section doesn't actually have to start with a number. TCL man pages use the 'n' section and 'man' resolves them just fine despite the ambiguity. Conversely, manpage names can also start with numbers, although this is rare (I found only one such example: man 30-systemd-environment-d-generator)

chasil

The POSIX standard manual pages for the utilities can be found here: https://pubs.opengroup.org/onlinepubs/9799919799/idx/xcu.htm... These would all be in section 1, if I am correct.

s20n

For me man(3) is the most interesting of them all. Run `apropos . | grep "(3)"`; you'll be surprised how many libraries come with man pages for their functions (e.g; curl). Now I wonder if there are any IDEs that can automatically dial into these man pages and pull up documentation for functions?

pfdietz

I'm feeling old now.

beej71

My favorite piece of man trivia is from the source of the tunefs BSD man page, which contains: .\" Take this out and a Unix Daemon will dog your steps from now until .\" the time_t's wrap around. .Pp You can tune a file system, but you cannot tune a fish. https://github.com/freebsd/freebsd-src/blob/main/sbin/tunefs...

et1337

Thousands of keystrokes saved by not having to type “man syscall”… and millions of hours lost by confused folks like OP (and myself)

throwanem

Remarkable that no one yet here, including the article author, reports the true origin of these section numbers: they identified (depending on section size, one or a group of) physical binders in the series published by AT&T to document System V UNIX, and when you got an update to your system software, it came with a package of new manual pages which you would physically install in the binders to replace the now-superseded older versions. Everything you hate about man pages is in consequence of that origin, and of the corollary that the online version was never designed to be authoritative. I have one of those physical binders, a volume of Section 3 for an AT&T 3B2, in the software section of my library downstairs. A beautiful artifact in every respect, of the level of quality you would imagine in the manual for a machine that cost $15,000 in the 80s.

mbo

Note that this is contrary to the convention used in the Erlang community, where the number is used to disambiguate function definitions with different parameter counts, e.g. in https://www.erlang.org/docs/18/man/supervisor.html we see definitions of `start_link/2` and `start_link/3`. It is a stylistic convention to always add this number to any reference to a function, even if there is only one definition.