Info files are usually kept in the `info' directory. You can read Info files using the standalone Info program or the Info reader built into Emacs. (See Info file `info', node `Top', for an introduction to Info.)
For Info to work, the `info' directory must contain a file that serves as a top level directory for the Info system. By convention, this file is called `dir'. (You can find the location of this file within Emacs by typing C-h i to enter Info and then typing C-x C-f to see the pathname to the `info' directory.)
The `dir' file is itself an Info file. It contains the top level menu for all the Info files in the system. The menu looks like this:
* Menu: * Info: (info). Documentation browsing system. * Emacs: (emacs). The extensible, self-documenting text editor. * Texinfo: (texinfo). With one source file, make either a printed manual using TeX or an Info file. ...
Each of these menu entries points to the `Top' node of the Info file that is named in parentheses. (The menu entry does not need to specify the `Top' node, since Info goes to the `Top' node if no node name is mentioned. See section Referring to Other Info Files.)
Thus, the `Info' entry points to the `Top' node of the `info' file and the `Emacs' entry points to the `Top' node of the `emacs' file.
In each of the Info files, the `Up' pointer of the `Top' node refers
back to the
dir file. For example, the line for the `Top'
node of the Emacs manual looks like this in Info:
File: emacs Node: Top, Up: (DIR), Next: Distrib
(Note that in this case, the `dir' file name is written in upper case letters--it can be written in either upper or lower case. Info has a feature that it will change the case of the file name to lower case if it cannot find the name as written.)
To add a new Info file to your system, you must write a menu entry to add to the menu in the `dir' file in the `info' directory. For example, if you were adding documentation for GDB, you would write the following new entry:
* GDB: (gdb). The source-level C debugger.
The first part of the menu entry is the menu entry name, followed by a colon. The second part is the name of the Info file, in parentheses, followed by a period. The third part is the description.
The name of an Info file often has a `.info' extension. Thus, the Info file for GDB might be called either `gdb' or `gdb.info'. The Info reader programs automatically try the file name both with and without `.info'; so it is better to avoid clutter and not to write `.info' explicitly in the menu entry. For example, the GDB menu entry should use just `gdb' for the file name, not `gdb.info'.
If an Info file is not in the `info' directory, there are three ways to specify its location:
Info-directory-listvariable in your personal or site initialization file. This tells Emacs's Info reader where to look for `dir' files. Emacs merges the files named `dir' from each of the listed directories. (In Emacs Version 18, you can set the
Info-directoryvariable to the name of only one directory.)
INFOPATHenvironment variable in your `.profile' or `.cshrc' initialization file. (Only you and others who set this environment variable will be able to find Info files whose location is specified this way.)
For example, to reach a test file in the `~bob/manuals' directory, you could add an entry like this to the menu in the `dir' file:
* Test: (/home/bob/manuals/info-test). Bob's own test file.
In this case, the absolute file name of the `info-test' file is written as the second part of the menu entry.
Alternatively, you could write the following in your `.emacs' file:
(setq Info-directory-list '("/home/bob/manuals" "/usr/local/emacs/info"))
This tells Emacs to merge the `dir' file from the `/home/bob/manuals' directory with the `dir' file from the `"/usr/local/emacs/info'" directory. Info will list the `/home/bob/manuals/info-test' file as a menu entry in the `/home/bob/manuals/dir' file.
Finally, you can tell Info where to look by setting the
INFOPATH environment variable in your `.cshrc' or
If you use
bash for your shell command interpreter,
you must set the
INFOPATH environment variable in the
`.profile' initialization file; but if you use
csh, you must
set the variable in the `.cshrc' initialization file. The two
files use slightly different command formats.
INFOPATHvariable as follows:
setenv INFOPATH .:~bob/manuals:/usr/local/emacs/info
INFOPATH=.:~bob/manuals:/usr/local/emacs/info export INFOPATH
The `.' indicates the current directory. Emacs uses the
INFOPATH environment variable to initialize the value of Emacs's
When you install an Info file onto your system, you can use the program
install-info to update the Info directory file `dir'.
Normally the makefile for the package runs
after copying the Info file into its proper installed location.
In order for the Info file to work with
install-info, you should
use the commands
@direntry in the
Texinfo source file. Use
@direntry to specify the menu entry to
add to the Info directory file, and use
@dircategory to specify
which part of the Info directory to put it in. Here is how these
commands are used in this manual:
@dircategory Texinfo documentation system @direntry * Texinfo: (texinfo). The GNU documentation format. * install-info: (texinfo)Invoking install-info. ... ... @end direntry
Here's what this produces in the Info file:
INFO-DIR-SECTION Texinfo documentation system START-INFO-DIR-ENTRY * Texinfo: (texinfo). The GNU documentation format. * install-info: (texinfo)Invoking install-info. ... ... END-INFO-DIR-ENTRY
install-info program sees these lines in the Info file, and
that is how it knows what to do.
Always use the
@dircategory commands near
the beginning of the Texinfo input, before the first
command. If you use them later on in the input,
will not notice them.
If you use
@dircategory more than once in the Texinfo source,
each usage specifies one category; the new menu entry is added to the
Info directory file in each of the categories you specify. If you use
@direntry more than once, each usage specifies one menu entry;
each of these menu entries is added to the directory in each of the
install-info inserts menu entries from an Info file into the
top-level `dir' file in the Info system (see the previous sections
for an explanation of how the `dir' file works). It's most often
run as part of software installation, or when constructing a dir file
for all manuals on a system. Synopsis:
install-info [option]... [info-file [dir-file]]
If info-file or dir-file are not specified, the various
options (described below) that define them must be. There are no
compile-time defaults, and standard input is never used.
install-info can read only one info file and write only one dir
file per invocation.
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