---
title: Reading UNIX Manual Pages
framework: os
role: article
role_heading: Article
path: os/reading-unix-manual-pages
---

# Reading UNIX Manual Pages

Use the Terminal app to read the documentation for low-level UNIX tools and APIs.

## Overview

Overview The UNIX online manual, known as the man pages, documents low-level UNIX command-line tools, APIs, and file formats. If you’re working at the lowest levels of the system, don’t miss out on this rich source of information. Display a Man Page in the Terminal App Type man and the name of a tool or API whose documentation you want to access, and press Return.

Because the man page is larger than the window, Terminal displays only the first part of the page. Press Space to display subsequent parts, or press Q to exit the man tool. important: Developer-oriented man pages are distributed as part of Xcode. The man tool searches for man pages within the active developer directory. If you have multiple copies of Xcode installed, you can select your active developer directory using the xcode-select command-line tool. See the xcode-select man page for details. Search a Specific Section Section 1 of the man pages covers command-line tools, section 2 covers system calls, section 3 covers user-space libraries, and so on. If you don’t specify a section, man displays the page from the first section that has a matching entry. For example, the following command displays the man page for the open command-line tool. $ man open If you want to get the man page for the open system call, specify section 2. $ man 2 open If you’re not sure which section to use, do a keyword search using the -k option. For example, the following command shows all the man pages that mention open. $ man -k open Learn More About Man Pages The man command-line tool has its own man page, which is a good place to learn more about this feature. $ man man