2. Advanced Info Commands

This chapter describes various advanced Info commands. (If you are using a stand-alone Info reader, there are additional commands specific to it, which are documented in several chapters of (info-stnd)Top section ‘GNU Info’ in GNU Info.)

One advanced command useful with most of the others described here is C-q, which “quotes” the next character so that it is entered literally (see (xemacs)Inserting Text section ‘Inserting Text’ in XEmacs User’s Manual). For example, pressing ? ordinarily brings up a list of completion possibilities. If you want to (for example) search for an actual ‘?’ character, the simplest way is to insert it using C-q ?. This works the same in XEmacs and stand-alone Info.

2.1 s searches Info documents

The commands which move between and inside nodes allow you to read the entire manual or its large portions. But what if you need to find some information in the manual as fast as you can, and you don’t know or don’t remember in what node to look for it? This need arises when you use a manual as a reference, or when it is impractical to read the entire manual before you start using the programs it describes.

Info has powerful searching facilities that let you find things quickly. You can search either the manual text or its indices.

The s command allows you to search a whole Info file for a string. It switches to the next node if and when that is necessary. You type s followed by the string to search for, terminated by <RET>. To search for the same string again, just s followed by <RET> will do. The file’s nodes are scanned in the order they are in the file, which has no necessary relationship to the order that they may be in the tree structure of menus and ‘next’ pointers. But normally the two orders are not very different. In any case, you can always look at the mode line to find out what node you have reached, if the header is not visible (this can happen, because s puts your cursor at the occurrence of the string, not at the beginning of the node).

In XEmacs, Meta-s is equivalent to s. That is for compatibility with other GNU packages that use M-s for a similar kind of search command. Both s and M-s run in XEmacs the command Info-search.

Instead of using s in XEmacs Info and in the stand-alone Info, you can use an incremental search started with C-s or C-r. It can search through multiple Info nodes. See (xemacs)Incremental Search section ‘Incremental Search’ in XEmacs User’s Manual. In XEmacs, you can disable this behavior by setting the variable Info-isearch-search to nil (see section XEmacs Info-mode Variables).

2.2 i searches the indices for specific subjects

Since most topics in the manual should be indexed, you should try the index search first before the text search. The i command prompts you for a subject and then looks up that subject in the indices. If it finds an index entry with the subject you typed, it goes to the node to which that index entry points. You should browse through that node to see whether the issue you are looking for is described there. If it isn’t, type , one or more times to go through additional index entries which match your subject.

The i command and subsequent , commands find all index entries which include the string you typed as a substring. For each match, Info shows in the echo area the full index entry it found. Often, the text of the full index entry already gives you enough information to decide whether it is relevant to what you are looking for, so we recommend that you read what Info shows in the echo area before looking at the node it displays.

Since i looks for a substring, you can search for subjects even if you are not sure how they are spelled in the index. For example, suppose you want to find something that is pertinent to commands which complete partial input (e.g., when you type <TAB>). If you want to catch index entries that refer to “complete,” “completion,” and “completing,” you could type icomplet<RET>.

Info documents which describe programs should index the commands, options, and key sequences that the program provides. If you are looking for a description of a command, an option, or a key, just type their names when i prompts you for a topic. For example, if you want to read the description of what the C-l key does, type iC-l<RET> literally.

If you aren’t sure which manual documents the topic you are looking for, try the M-x info-apropos command in XEmacs, or the M-x index-apropos command in the stand-alone reader. It prompts for a string and then looks up that string in all the indices of all the Info documents installed on your system.

2.3 g goes to a node by name

If you know a node’s name, you can go there by typing g, the name, and <RET>. Thus, gTop<RET> would go to the node called ‘Top’ in this file. (This is equivalent to t, see Some intermediate Info commands.) gGo to node<RET> would come back here.

Unlike m, g does not allow the use of abbreviations. But it does allow completion, so you can type <TAB> to complete a partial node name.

To go to a node in another file, you can include the file name in the node name by putting it at the front, in parentheses. Thus, g(dir)Top<RET> would go to the Info Directory node, which is the node ‘Top’ in the Info file ‘dir’. Likewise, g(xemacs)Top<RET> goes to the top node of the XEmacs manual.

The node name ‘*’ specifies the whole file. So you can look at all of the current file by typing g*<RET> or all of any other file with g(filename)*<RET>.

2.4 1–9 choose a menu subtopic by its number

If you begrudge each character of type-in which your system requires, you might like to use the commands 1, 2, 3, 4, …, 9. They are short for the m command together with a name of a menu subtopic. 1 goes through the first item in the current node’s menu; 2 goes through the second item, etc. In the stand-alone reader, 0 goes through the last menu item; this is so you need not count how many entries are there.

If your display supports multiple fonts, colors or underlining, and you are using XEmacs’ Info mode to read Info files, the third, sixth and ninth menu items have a ‘*’ that stands out, either in color or in some other attribute, such as underline; this makes it easy to see at a glance which number to use for an item.

Some terminals don’t support either multiple fonts, colors or underlining. If you need to actually count items, it is better to use m instead, and specify the name, or use <TAB> to quickly move between menu items.

2.5 M-n creates a new independent Info buffer in XEmacs

If you are reading Info in XEmacs, you can select a new independent Info buffer in a new XEmacs window by typing M-n. The new buffer starts out as an exact copy of the old one, but you will be able to move independently between nodes in the two buffers. (In Info mode, M-n runs the XEmacs command clone-buffer.)

In XEmacs Info, you can also produce new Info buffers by giving a numeric prefix argument to the m and g commands. C-u m and C-u g go to a new node in exactly the same way that m and g do, but they do so in a new Info buffer which they select in another window.

Another way to produce new Info buffers in XEmacs is to use a numeric prefix argument for the C-h i command (info) which switches to the Info buffer with that number. Thus, C-u 2 C-h i switches to the buffer ‘*info*<2>’, creating it if necessary.

2.6 XEmacs Info-mode Variables

The following variables may modify the behavior of Info-mode in XEmacs; you may wish to set one or several of these variables interactively, or in your init file. See Examining and Setting Variables: (xemacs)Examining section ‘Examining and Setting Variables’ in XEmacs User’s Manual. The stand-alone Info reader program has its own set of variables, described in (info-stnd)Variables section ‘Manipulating Variables’ in GNU Info.

Info-directory-list

The list of directories to search for Info files. Each element is a string (directory name) or nil (try default directory). If not initialized Info uses the environment variable INFOPATH to initialize it, or Info-default-directory-list if there is no INFOPATH variable in the environment.

If you wish to customize the Info directory search list for both XEmacs Info and stand-alone Info, it is best to set the INFOPATH environment variable, since that applies to both programs.

Info-additional-directory-list

A list of additional directories to search for Info documentation files. These directories are not searched for merging the ‘dir’ file.

Info-mode-hook

Hooks run when Info-mode is called. By default, it contains the hook turn-on-font-lock which enables highlighting of Info files. You can change how the highlighting looks by customizing the faces info-node, info-xref, info-xref-visited, info-header-xref, info-header-node, info-menu-header, info-menu-star, and info-title-n (where n is the level of the section, a number between 1 and 4). To customize a face, type M-x customize-face <RET> face <RET>, where face is one of the face names listed here.

Info-fontify-maximum-menu-size

Maximum size of menu to fontify if font-lock-mode is non-nil.

Info-fontify-visited-nodes

If non-nil, menu items and cross-references pointing to visited nodes are displayed in the info-xref-visited face.

Info-use-header-line

If non-nil, XEmacs puts in the Info buffer a header line showing the ‘Next’, ‘Prev’, and ‘Up’ links. A header line does not scroll with the rest of the buffer, making these links always visible.

Info-hide-note-references

As explained in earlier nodes, the XEmacs version of Info normally hides some text in menus and cross-references. You can completely disable this feature, by setting this option to nil. Setting it to a value that is neither nil nor t produces an intermediate behavior, hiding a limited amount of text, but showing all text that could potentially be useful.

Info-scroll-prefer-subnodes

If set to a non-nil value, <SPC> and <BACKSPACE> (or <DEL>) keys in a menu visit subnodes of the current node before scrolling to its end or beginning, respectively. For example, if the node’s menu appears on the screen, the next <SPC> moves to a subnode indicated by the following menu item. Setting this option to nil results in behavior similar to the stand-alone Info reader program, which visits the first subnode from the menu only when you hit the end of the current node. The default is nil.

Info-isearch-search

If non-nil, isearch in Info searches through multiple nodes.

Info-enable-active-nodes

When set to a non-nil value, allows Info to execute Lisp code associated with nodes. The Lisp code is executed when the node is selected. The Lisp code to be executed should follow the node delimiter (the ‘DEL’ character) and an ‘execute: ’ tag, like this:

^_execute: (message "This is an active node!")

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