Explain the sections

Learn

Manual sections

Manuals are split into numbered sections by kind of thing, so the same name can appear in more than one:

1: user commands (ls, grep)
5: file formats and config files (e.g. passwd the file)
8: system administration commands

So passwd (1) is the command you run to change a password, while passwd (5) documents the /etc/passwd file format: different pages, same name, told apart by the section number.

This step isn't a command: answer the questions below.

Your task

Feedback Report a problem

Answer the questions below about manual sections.

What does the (1) in ls(1) mean?It's the first version of the ls pagels takes one argumentThe page is in manual section 1: user commands

Why does man 5 passwd need the section number?passwd is both a command (section 1) and a file format (section 5)Section 5 pages are hidden unless you ask for themBecause passwd needs root to read

Interview prep

Knowing how to read the manual is what lets you pick up any command on the job; interviewers notice when you reach for man instead of guessing.

You're on a server with no internet and don't remember a command's flags. What do you do?

Read its manual in place: man <cmd> opens the page, and man <cmd> | grep <keyword> jumps straight to the flag I need. If I don't even know the command's name, apropos <keyword> (a.k.a. man -k) searches every manual's summary by topic, and whatis <cmd> gives the one-line reminder. The section number in ls (1) tells me which manual section the page lives in — handy when a name exists in several (e.g. passwd (1) the command vs passwd (5) the file).