APT isn't installing man pages by default

Question

I have installed a minimal Debian 9 through CD image. I configured Apt to not install recommended packages and now the system don't have any man page.

man apt-get, man mkdir, or man ping doesn't show any man page; instead, I get

bash: man: command not found

Solution 1

bash: man: command not found

means that you need to install the man-db package.

Manpages are installed by default in most cases, because Debian policy strongly encourages them to be shipped in the same package as the commands themselves:

Each program, utility, and function should have an associated manual page included in the same package.

Solution 2

The apt package which contain apt-get, also contains the manpage for apt-get (it even contains it in 7 languages), so if you have apt-get installed, you really should have the manpage. If you don't you've messed up your system in a way beyond what any packaging system can help you with.

Similar can be said for mkdir in the coreutils package, and for ping in iputils-ping.

But configuring APT to not install recommends (which I also always do, and believe to be a good thing), will mean that you don't get manpages of any program where the Debian developer making the package has chosen not to include it in the package, but in a package that is only a recommandation. I guess there's a lot of options, but some number of programs have manpages in the manpages package.

Solution 3

FWIW if you try and install Debian under Windows using WSL, then you do not get the man pages as default (I imagine this may also be a minimal installation). This is easily remedied using the method that Stephen Kitt suggests in a previous answer, but for the avoidance of doubt the command is:

sudo apt-get install man-db

If you install the build-essential packages (e.g. to install a C compiler), then you MAY need to also use:

sudo apt-get install manpages-dev

Comments

[Knud Larsen]

"man pages" are on-line : man apt-get linux.die.net/man/8/apt-get or manpages.ubuntu.com/manpages/xenial/man8/apt.8.html ... man mkdir (1) man7.org/linux/man-pages/man1/mkdir.1.html , etc. etc.

[Stephen Kitt]

@Knud since the OP is using Debian, the appropriate site for online manpages is manpages.debian.org.

[Pablo A]

Sure, but there is any reason why Debian 9 doesn't ship with man-db (and hence man) installed by default?

[Stephen Kitt]

@Pablo what makes you think it doesn’t? The OP explicitly performed a minimal install and configured apt to ignore “Recommends”. That’s not the default installation. man-db is “Priority: standard” and installed in the default installation, but not in the minimal one.

[Pablo A]

OK, so Digital Ocean Debian default droplet (at least with 9.6 x64) installation is a minimal one.