Man page/Navigate/zh-cn

本指南介绍如何使用man浏览手册页.

man程序
Everyone at some point in their Linux life has used it: the command. However, while the man program itself appears to be rather simplistic in its construct, it has a few extra abilities than just simply scrolling through the page. This document hopes to help shed some light on these capabilities.

Man 布局
Man pages are mainly stored in the directory. However, as long as a man page is located in the MANPATH environment variable, man will be able to pick it up. Gentoo will generally store MANPATH variables in. Within these directories are some folders with the structure manX where X is the section number. For example, a standard man layout might look like so:

The actual section numbering appears fairly standard. However, notice that there is a and some  folders. The following table lists the above man page directories and what is contained within them:

While this is not an extensive and detailed list, it does cover the man pages that most people will be interested in. However, sometimes you can find out what a section does as easily as looking at this table. The next chapter will look at using man to traverse this layout.

Browsing the man layout
Now that we understand the man layout, we can begin to look it over for commands. Sometimes we may need to narrow down what man page we want. The first way would be addressing by section. To find out a description of a section, one can use man intro like so:

Unfortunately, this does not always work! However, luckily for us there is another way to search for commands that may return multiple results (such as a library call and system command having the same name). To do so, we use the  option to the man command like so:

Sometimes the output may be a lot larger. In this case it might be better to specify more specific keywords. Now that we know where to find the man page, the next section will look at viewing the man page.

Viewing man pages
Viewing man pages can be done in 2 ways, first is with. The second way is. Take for example. I can view either the first man page that comes up on (which would be section 1, because it is the lowest section containing a man page on bc):

However, what if I want the POSIX version? Then I can use the second form:

And the man page is displayed. Now that we have the man page up, it is time to work with it. The next section will look at navigation and searching.

Navigating and searching man pages
Navigating a man page is fairly simple. To move up and down line by line, use the and  arrow keys. To move up page by page, you can use the and  keys. Do however note that these navigation instructions assume the environmental PAGER variable is set to use the default pager,. Less also has a few other commands for navigation, but the arrow keys usually suffice:

Searching, however, is more interesting. The two most basic searches are  and. The first version searches forwards, and the second searches backwards. is a regular expression pattern that is described in. Let's take for example searching for the  option to. First, bring up the emerge man page:

Then, at the screen, press the key to bring up the entry prompt to search forwards and enter in our search pattern:

This will search the man page, and bring the searched item into focus:

If you hit a search result by accident and want to continue searching for the same results, simply press the key again, and press  (i.e. don't put a pattern it). This will cause the search to default to the last pattern used. Now with some man pages, options are listed, then explained later on. Take the man page. It lists the files used, then explains their usage. Searching forward a few times would return the results, but there's an easier way to handle this, with the second search form, backwards searching. Let's use this to find the description on. First, bring up man 5 portage:

Now press +. This will bring you to the end of the page:

Now we'll go ahead and enter the pattern to search for with the  backwards search option. First press the key to bring up the prompt, and then enter in, our query:

Then hit to bring up the result:

And the search is complete! Note that just as with, using   search with no pattern will use the last pattern to search.

总结
This concludes the man guide. This will hopefully shed some light on navigating man pages, and maybe even give a few new tips to the more experienced users. For those who prefer alternate means of navigating man pages, the following are also available:


 * - A program for converting man pages to HTML.
 * - A tk based man page browser.

Also the KDE web browser can browse man pages using the   syntax in the address bar.