本篇介绍在ubuntu上安装C++在线文档（man pages），下篇将介绍C++在线文档的使用。需要注意的一点是：在这里的方法有别于通常的 man func_name，因此需要单独说明，以免安装后也不知道怎么用。

另外，为了达到最好的使用效果，请首先把C的开发文档提前安装上吧，命令：

sudo apt-get install update

sudo apt-get install manpages-dev glibc-doc

然后安装C++的开发文档，命令通常是

sudo apt-get install libstdc++6-4.4-doc

上面的4.4是gcc的版本，可以是4.2、4.3、4.4, 4.4是最新的。至于软件库中有无4.4，请参见下文的说明，使用命令查询：

apt-cache search libstdc++|grep "doc"

以决定安装4.2、4.3或4.4

下面是英文原文：

It’s so easy to search for any C related programming functions. All you need is to search the man pages. Take for example, if you want to know more about printf, simply type
`$ man 2 printf`

But that’s not the case with C++ functions. Every time, you have to go to the web for any doubts related to C++ functions. There are two ways by which you can search for documentation related to C++ functions.

    Man pages for C++ functions
    HTML documentation

Both of the above are available from a single package. To install C++ documentation
`$ sudo apt-get install libstdc++6-4.4-doc`

This installs both the man pages and HTML documentation.
The HTML documentation is found in the following path:file:///usr/share/doc/libstdc++6-4.4-doc/libstdc++/html/index.html

If you are struggling to search C++ man pages, ReferHow to search C++ man pages
Now there may be case that when you are referring this article the documentation 6.4.4 version is no longer available.

In that case, follow the following steps
`$ apt-cache search libstdc++|grep"doc"`

libstdc++6-4.4-doc - The GNU Standard C++ Library v3 (documentation files)libstdc++6-4.1-doc - The GNU Standard C++ Library v3 (documentation files)libstdc++6-4.3-doc - The GNU Standard C++ Library v3 (documentation files)

Search for the libstdc++ docs as shown above and install the version you want, preferably the latest ones (as shown above)

`$ sudo apt-get install libstdc++6-4.4-doc`