How to Install Offline C++ Man Pages on Linux

Overview

Linux's man command provides manual pages for C functions, but C++ library documentation is not installed by default. This guide shows how to obtain and configure offline C++ man pages.

How man locates manuals

The utility searches directories listed in /etc/man_db.conf. The MANDATORY_MANPATH entry defines additional paths that are always searched.

Installation steps

1. Download the C++ man‑page archive

Choose a GCC mirror (e.g., http://gcc.gnu.org/mirrors.html) and navigate to the libstdc++/doxygen directory. Download the compressed package that contains the man pages, for example:

libstdc++-api.20140403.man.tar.bz2

2. Extract the archive

tar -xvf libstdc++-api.20140403.man.tar.bz2

The extraction creates a directory libstdc++-api.20140403.man with a subdirectory man3 that holds the C++ reference pages.

Create a dedicated location for the pages (root privileges may be required): mkdir -p /usr/local/cpp/man Copy the man3 tree into that location:

cp -rf ./libstdc++-api.20140403.man/man3 /usr/local/cpp/man/

3. Register the new path with man

Open the configuration file and add the directory to MANDATORY_MANPATH:

# /etc/man_db.conf
MANDATORY_MANPATH   /usr/local/cpp/man

Save the file. The man command will now include this path when searching for manuals.

Verification

Query a C++ symbol, remembering to include the namespace and class name: man std::cout If the entry is found, you will see a page such as std::iostream.3. For symbols that are not directly indexed, you can search inside the manual using the forward slash:

/size   # searches for the word “size” in the current page

Alternative online references

https://en.cppreference.com/ (English)

https://zh.cppreference.com/ (Chinese)

http://www.cplusplus.com/

Summary of required actions

Download the C++ man‑page archive from a GCC mirror.

Extract the man3 directory.

Copy it to a dedicated location, e.g. /usr/local/cpp/man.

Add that location to MANDATORY_MANPATH in /etc/man_db.conf.

Use man std::<symbol> to view C++ library documentation.