Remove string.h hack.

[bpt/emacs.git] / man / faq.texi

\input texinfo   @c -*-texinfo-*-  -*- coding: latin-1 -*-
@c %**start of header
@setfilename ../info/efaq
@settitle GNU Emacs FAQ
@c %**end of header

@setchapternewpage odd

@c The @ifinfo stuff only appears in the Info version
@ifinfo
@dircategory Editors
@direntry
* Emacs FAQ: (efaq).	Frequently Asked Questions about Emacs.
@end direntry

Copyright 1994,1995,1996,1997,1998,1999 Reuven M. Lerner@*
Copyright 1992,1993 Steven Byrnes@*
Copyright 1990,1991,1992 Joseph Brian Wells@*

This list of frequently asked questions about GNU Emacs with answers
("FAQ") may be translated into other languages, transformed into other
formats (e.g. Texinfo, Info, WWW, WAIS), and updated with new information.

The same conditions apply to any derivative of the FAQ as apply to the FAQ
itself.  Every copy of the FAQ must include this notice or an approved
translation, information on who is currently maintaining the FAQ and how to
contact them (including their e-mail address), and information on where the
latest version of the FAQ is archived (including FTP information).

The FAQ may be copied and redistributed under these conditions, except that
the FAQ may not be embedded in a larger literary work unless that work
itself allows free copying and redistribution.

[This version has been somewhat edited from the last-posted version
(as of August 1999) for inclusion in the Emacs distribution.]

@end ifinfo

@c The @titlepage stuff only appears in the printed version
@titlepage
@sp 10
@center @titlefont{GNU Emacs FAQ}

@c The following two commands start the copyright page.
@page
@vskip 0pt plus 1filll
Copyright @copyright{} 1994,1995,1996,1997,1998,1999 Reuven M. Lerner@*
Copyright @copyright{} 1992,1993 Steven Byrnes@*
Copyright @copyright{} 1990,1991,1992 Joseph Brian Wells@*

This list of frequently asked questions about GNU Emacs with answers
("FAQ") may be translated into other languages, transformed into other
formats (e.g. Texinfo, Info, WWW, WAIS), and updated with new information.

The same conditions apply to any derivative of the FAQ as apply to the FAQ
itself.  Every copy of the FAQ must include this notice or an approved
translation, information on who is currently maintaining the FAQ and how to
contact them (including their e-mail address), and information on where the
latest version of the FAQ is archived (including FTP information).

The FAQ may be copied and redistributed under these conditions, except that
the FAQ may not be embedded in a larger literary work unless that work
itself allows free copying and redistribution.

[This version has been somewhat edited from the last-posted version
(as of August 1999) for inclusion in the Emacs distribution.]
@end titlepage

@node    Top, FAQ notation, (dir), (dir)

This is the GNU Emacs FAQ, last updated on @today{}.

The FAQ is slowly but surely being turned into a Texinfo document,
allowing us to create HTML, Info, and TeX documents from a single source
file.  Please bear with us as we improve on this format.  If you have
any suggestions or questions, please contact
@email{emacs-faq@@lerner.co.il, the FAQ maintainers}.

@menu
* FAQ notation::                
* General questions::           
* Getting help::                
* Status of Emacs::             
* Common requests::             
* Bugs and problems::           
* Compiling and installing Emacs::  
* Finding Emacs and related packages::  
* Major packages and programs::  
* Key bindings::                
* Alternate character sets::    
* Mail and news::               
* Concept index::               
@end menu

@c ------------------------------------------------------------
@node FAQ notation, General questions, Top, Top
@chapter FAQ notation
@cindex FAQ notation

This section describes notation used in the GNU Emacs FAQ, as well as in
the Emacs documentation.  Consult this section if this is the first time
you are reading the FAQ, or if you are confused by notation or terms
used in the FAQ.

@menu
* Basic keys::                  
* Extended commands::           
* On-line manual::              
* Filename conventions::        
* Common acronyms::             
@end menu

@node Basic keys, Extended commands, FAQ notation, FAQ notation
@section What do these mean: @kbd{C-h}, @kbd{M-C-a}, @key{RET}, @kbd{@key{ESC} a}, etc.?
@cindex Basic keys
@cindex Control key, notation for
@cindex @key{Meta} key, notation for
@cindex Control-meta characters, notation for
@cindex @kbd{C-h}, definition of
@cindex @kbd{M-C-h}, definition of
@cindex @key{DEL}, definition of
@cindex @key{ESC}, definition of
@cindex @key{LFD}, definition of
@cindex @key{RET}, definition of
@cindex @key{SPC}, definition of
@cindex @key{TAB}, definition of

@itemize @bullet

@item
@kbd{C-x}: press the @key{x} key while holding down the @key{Control} key

@item
@kbd{M-x}: press the @key{x} key while holding down the @key{Meta} key
(if your computer doesn't have a @key{Meta} key, see @pxref{No Meta key})

@item
@kbd{M-C-x}: press the @key{x} key while holding down both @key{Control}
and @key{Meta}

@item
@kbd{C-M-x}: a synonym for the above

@item
@key{LFD}: Linefeed or Newline; same as @kbd{C-j}

@item
@key{RET}: @key{Return}, sometimes marked @key{Enter}; same as @kbd{C-m}

@item
@key{DEL}: @key{Delete}, usually not the same as @key{Backspace}; same
     as @kbd{C-?}  (@pxref{Backspace invokes help} if deleting invokes Emacs help)

@item
@key{ESC}: Escape; same as @kbd{C-[}

@item
@key{TAB}: Tab; same as @kbd{C-i}

@item
@key{SPC}: Space bar

@end itemize

Key sequences longer than one key (and some single-key sequences) are
inside double quotes or on lines by themselves.  Any real spaces in such
a key sequence should be ignored; only @key{SPC} really means press the
space key.

The ASCII code sent by @kbd{C-x} (except for @kbd{C-?}) is the value
that would be sent by pressing just @key{x} minus 96 (or 64 for
uppercase @key{X}) and will be from 0 to 31.  The ASCII code sent by
@kbd{M-x} is the sum of 128 and the ASCII code that would be sent by
pressing just @key{x}.  Essentially, @key{Control} turns off bits 5 and
6 and @key{Meta} turns on bit 7.

@kbd{C-?} (aka @key{DEL}) is ASCII code 127.  It is a misnomer to call
@kbd{C-?}  a "control" key, since 127 has both bits 5 and 6 turned ON.
Also, on very few keyboards does @kbd{C-?} generate ASCII code 127.

@inforef{Characters, Characters, emacs} and @inforef{Keys, Keys, emacs}
for more information.  (@pxref{On-line manual} for more information about
Info.)

@node Extended commands, On-line manual, Basic keys, FAQ notation
@section What does @file{M-x @var{command}} mean?
@cindex Extended commands
@cindex Commands, extended
@cindex M-x, meaning of

@kbd{M-x @var{command}} means type @kbd{M-x}, then type the name of the
command, then type @key{RET}.  (@pxref{Basic keys} if you're not sure
what @kbd{M-x} and @key{RET} mean.)

@kbd{M-x} (by default) invokes the command
@code{execute-extended-command}.  This command allows you to run any
Emacs command if you can remember the command's name.  If you can't
remember the command's name, you can type @key{TAB} and @key{SPC} for
completion, @key{?} for a list of possibilities, and @kbd{M-p} and
@kbd{M-n} to see previous commands entered.  An Emacs "command" is any
"interactive" Emacs function.

Your system administrator may have bound other key sequences to invoke
@code{execute-extended-command}.  A function key labeled @kbd{Do} is a
good candidate for this.

To run non-interactive Emacs functions, @pxref{Evaluating Emacs Lisp code}.

@node On-line manual, Filename conventions, Extended commands, FAQ notation
@section How do I read topic XXX in the on-line manual?
@cindex On-line manual, reading topics in
@cindex Reading topics in the on-line manual
@cindex Finding topics in the on-line manual
@cindex Info, finding topics in

When we refer you to topic XXX in the on-line manual, you can read this
manual node inside Emacs (assuming nothing is broken) by typing @kbd{C-h
i m emacs @key{RET} m XXX @key{RET}}.

This invokes Info, the GNU hypertext documentation browser.  If you don't
already know how to use Info, type @key{?} from within Info.

If we refer to topic XXX:YYY, type @kbd{C-h i m emacs @key{RET} m XXX
@key{RET} m YYY @key{RET}}.

Your system administrator may not have installed the Info files, or may
have installed them improperly.  In this case you should complain.

@xref{Getting a printed manual}, if you would like a paper copy of the
Emacs manual.

@node Filename conventions, Common acronyms, On-line manual, FAQ notation
@section What are @file{etc/SERVICE}, @file{src/config.h}, and @file{lisp/default.el}?
@cindex Filename conventions
@cindex Conventions for filenames
@cindex Directories and files that come with Emacs

These are files that come with Emacs.  The Emacs distribution is divided
into subdirectories; the important ones are @file{etc}, @file{lisp}, and
@file{src}.

If you use Emacs, but don't know where it is kept on your system, start
Emacs, then type @kbd{C-h v data-directory @key{RET}}.  The directory
name displayed by this will be the full pathname of the installed
@file{etc} directory.

The location of your Info directory (i.e., where on-line documentation
is stored) is kept in the variable @code{Info-default-directory-list}.  Use
@kbd{C-h v Info-default-directory-list @key{RET}} to see the contents of
this variable, which will be a list of directory names.  The last
directory in that list is probably where most Info files are stored.  By
default, Info documentation is placed in @file{/usr/local/info}.

Some of these files are available individually via FTP or e-mail;
@pxref{Informational files for Emacs}.  All are available in the source
distribution.  Many of the files in the @file{etc} directory are also
available via the Emacs "help" menu, or by typing @kbd{C-h ?} (@kbd{M-x
help-for-help}).

Your system administrator may have removed the @file{src} directory and
many files from the @file{etc} directory.

@node Common acronyms,  , Filename conventions, FAQ notation
@section What are FSF, LPF, OSF, GNU, RMS, FTP, and GPL?
@cindex FSF, definition of
@cindex LPF, definition of
@cindex OSF, definition of
@cindex GNU, definition of
@cindex RMS, definition of
@cindex Stallman, Richard, acronym for
@cindex Richard Stallman, acronym for
@cindex FTP, definition of
@cindex GPL, definition of
@cindex Acronyms, definitions for
@cindex Common acronyms, definitions for

@table @asis

@item FSF
Free Software Foundation

@item LPF
League for Programming Freedom

@item OSF
Open Software Foundation

@item GNU
GNU's Not Unix

@item RMS
Richard Matthew Stallman

@item FTP
File Transfer Protocol

@item GPL
GNU General Public License

@end table

Avoid confusing the FSF, the LPF, and the OSF.  The LPF opposes
look-and-feel copyrights and software patents.  The FSF aims to make
high quality free software available for everyone.  The OSF is a
consortium of computer vendors which develops commercial software for
Unix systems.

The word "free" in the title of the Free Software Foundation refers to
"freedom," not "zero dollars."  Anyone can charge any price for
GPL-covered software that they want to.  However, in practice, the
freedom enforced by the GPL leads to low prices, because you can always
get the software for less money from someone else, because everyone has
the right to resell or give away GPL-covered software.

@c ------------------------------------------------------------
@node    General questions, Getting help, FAQ notation, Top
@chapter General questions
@cindex General questions

This section contains general questions having to do with Emacs, the
Free Software Foundation, and related organizations.

@menu
* The LPF::                     
* Real meaning of copyleft::    
* Guidelines for newsgroup postings::  
* Newsgroup archives::          
* Reporting bugs::              
* Unsubscribing from Emacs lists::  
* Contacting the FSF::          
@end menu

@node The LPF, Real meaning of copyleft, General questions, General questions
@section What is the LPF?
@cindex LPF, description of
@cindex League for Programming Freedom
@cindex Software patents, opposition to
@cindex Patents for software, opposition to

The LPF opposes the expanding danger of software patents and
look-and-feel copyrights.  To get more information, feel free to contact
the LPF via e-mail or otherwise.  You may also contact
@email{jbw@@cs.bu.edu, Joe Wells}; he will be happy to talk with you
about the LPF.

You can find more information about the LPF in the file @file{etc/LPF}.
More papers describing the LPF's views are available on the Internet and
also from @uref{http://lpf.ai.mit.edu/, the LPF}.

@node Real meaning of copyleft, Guidelines for newsgroup postings, The LPF, General questions
@section What is the real legal meaning of the GNU copyleft?
@cindex Copyleft, real meaning of
@cindex GPL, real meaning of
@cindex General Public License, real meaning of
@cindex Discussion of the GPL

The real legal meaning of the GNU General Public License (copyleft) will
only be known if and when a judge rules on its validity and scope.
There has never been a copyright infringement case involving the GPL to
set any precedents.  Please take any discussion regarding this issue to
the newsgroup @uref{news:gnu.misc.discuss}, which was created to hold the
extensive flame wars on the subject.

RMS writes:

@quotation
The legal meaning of the GNU copyleft is less important than the spirit,
which is that Emacs is a free software project and that work pertaining
to Emacs should also be free software.  "Free" means that all users have
the freedom to study, share, change and improve Emacs.  To make sure
everyone has this freedom, pass along source code when you distribute
any version of Emacs or a related program, and give the recipients the
same freedom that you enjoyed.
@end quotation

@node Guidelines for newsgroup postings, Newsgroup archives, Real meaning of copyleft, General questions
@section  What are appropriate messages for @uref{news:gnu.emacs.help}, @uref{news:gnu.emacs.bug}, @uref{news:comp.emacs}, etc.?
@cindex Newsgroups, appropriate messages for
@cindex GNU newsgroups, appropriate messages for
@cindex Usenet groups, appropriate messages for
@cindex Mailing lists, appropriate messages for

The file @file{etc/MAILINGLISTS} discusses the purpose of each GNU
mailing-list.  (@pxref{Informational files for Emacs} if you want a copy
of the file.)  For those lists which are gatewayed with newsgroups, it
lists both the newsgroup name and the mailing list address.

@uref{news:comp.emacs} is for discussion of Emacs programs in general.
This includes Emacs along with various other implementations, such as
JOVE, MicroEmacs, Freemacs, MG, Unipress, CCA, and Epsilon.

Many people post Emacs questions to @uref{news:comp.emacs} because they
don't receive any of the gnu.* newsgroups.  Arguments have been made
both for and against posting GNU-Emacs-specific material to
@uref{news:comp.emacs}.  You have to decide for yourself.

Messages advocating "non-free" software are considered unacceptable on
any of the gnu.* newsgroups except for @uref{news:gnu.misc.discuss},
which was created to hold the extensive flame-wars on the subject.
"Non-free" software includes any software for which the end user can't
freely modify the source code and exchange enhancements.  Be careful to
remove the gnu.* groups from the "Newsgroups:" line when posting a
followup that recommends such software.

@uref{news:gnu.emacs.bug} is a place where bug reports appear, but avoid
posting bug reports to this newsgroup (@pxref{Reporting bugs}).

@node Newsgroup archives, Reporting bugs, Guidelines for newsgroup postings, General questions
@section Where can I get old postings to @uref{news:gnu.emacs.help} and other GNU groups?
@cindex Archived postings from @uref{news:gnu.emacs.help}
@cindex Usenet archives for GNU groups
@cindex Old Usenet postings for GNU groups

The FSF has maintained archives of all of the GNU mailing lists for many
years, although there may be some unintentional gaps in coverage.  The
archive is not particularly well organized or easy to retrieve
individual postings from, but pretty much everything is there.

The archive is at @uref{ftp://ftp-mailing-list-archives.gnu.org}.

As of this writing, the archives are not yet working.

Web-based Usenet search services, such as
@uref{http://www.dejanews.com, DejaNews}, also archive the
gnu.* groups.

@node Reporting bugs, Unsubscribing from Emacs lists, Newsgroup archives, General questions
@section Where should I report bugs and other problems with Emacs?
@cindex Bug reporting
@cindex Good bug reports
@cindex How to submit a bug report
@cindex Reporting bugs

The correct way to report Emacs bugs is by e-mail to
@email{bug-gnu-emacs@@gnu.org}.  Anything sent here also appears in the
newsgroup @uref{news:gnu.emacs.bug}, but please use e-mail instead of
news to submit the bug report.  This ensures a reliable return address
so you can be contacted for further details.

Be sure to read the "Bugs" section of the Emacs manual before reporting
a bug to bug-gnu-emacs!  The manual describes in detail how to submit a
useful bug report.  (@pxref{On-line manual} if you don't know how to read the
manual.)

RMS says:

@quotation
Sending bug reports to @email{help-gnu-emacs@@gnu.org} (which has the
effect of posting on @uref{news:gnu.emacs.help}) is undesirable because
it takes the time of an unnecessarily large group of people, most of
whom are just users and have no idea how to fix these problem.
@email{bug-gnu-emacs@@gnu.org} reaches a much smaller group of people
who are more likely to know what to do and have expressed a wish to
receive more messages about Emacs than the others.
@end quotation

RMS says it is sometimes fine to post to @uref{news:gnu.emacs.help}:

@quotation
If you have reported a bug and you don't hear about a possible fix,
then after a suitable delay (such as a week) it is okay to post on
gnu.emacs.help asking if anyone can help you.
@end quotation

If you are unsure whether you have found a bug, consider the following
non-exhaustive list, courtesy of RMS:

@quotation
If Emacs crashes, that is a bug.  If Emacs gets compilation errors
while building, that is a bug.  If Emacs crashes while building, that
is a bug.  If Lisp code does not do what the documentation says it
does, that is a bug.
@end quotation

@node Unsubscribing from Emacs lists, Contacting the FSF, Reporting bugs, General questions
@section  How do I unsubscribe from this mailing list?
@cindex Unsubscribing from GNU mailing lists
@cindex Removing yourself from GNU mailing lists

If you are receiving a GNU mailing list named "XXX", you might be able
to unsubscribe from it by sending a request to the address
@email{XXX-request@@gnu.org}.  However, this will not work if you are
not listed on the main mailing list, but instead receive the mail from a
distribution point.  In that case, you will have to track down at which
distribution point you are listed.  Inspecting the @samp{Received} headers
on the mail messages may help, along with liberal use of the "EXPN" or
"VRFY" sendmail commands through "telnet <site-address> smtp".  Ask your
postmaster for help.

@node Contacting the FSF,  , Unsubscribing from Emacs lists, General questions
@section  What is the current address of the FSF?
@cindex Snail mail address of the FSF
@cindex Postal address of the FSF
@cindex Contracting the FSF
@cindex Free Software Foundation, contacting

@table @asis

@item E-mail
gnu@@gnu.org

@item Telephone
+1-617-542-5942

@item Fax
+1-617-542-2652

@item World Wide Web
@uref{http://www.gnu.org/}

@item Postal address
Free Software Foundation@*
59 Temple Place - Suite 330@*
Boston, MA 02111-1307@*
USA@*

@end table

For details on how to order items directly from the FSF, see the file
@file{etc/ORDERS}.

@c ------------------------------------------------------------
@node Getting help, Status of Emacs, General questions, Top
@chapter Getting help
@cindex Getting help

This section tells you how to get help with Emacs

@menu
* Basic editing::               
* Learning how to do something::  
* Getting a printed manual::    
* Emacs Lisp documentation::    
* Installing Texinfo documentation::  
* Printing a Texinfo file::     
* Viewing Info files outside of Emacs::  
* Informational files for Emacs::  
* Help installing Emacs::       
* Obtaining the FAQ::           
@end menu

@node Basic editing, Learning how to do something, Getting help, Getting help
@section I'm just starting Emacs; how do I do basic editing?
@cindex Basic editing with Emacs
@cindex Beginning editing
@cindex Tutorial, invoking the
@cindex Self-paced tutorial, invoking the
@cindex Help system, entering the

Type @kbd{C-h t} to invoke the self-paced tutorial.  Just typing @kbd{C-h}
enters the help system.

Your system administrator may have changed @kbd{C-h} to act like
@key{DEL} to deal with local keyboards.  You can use @kbd{M-x
help-for-help} instead to invoke help.  To discover what key (if any)
invokes help on your system, type @kbd{M-x where-is @key{RET}
help-for-help @key{RET}}.  This will print a comma-separated list of key
sequences in the echo area.  Ignore the last character in each key
sequence listed.  Each of the resulting key sequences invokes help.

Emacs help works best if it is invoked by a single key whose value
should be stored in the variable @code{help-char}.

There is also a WWW-based tutorial for Emacs 18, much of which is also
relevant for Emacs 20, available at

@uref{http://kufacts.cc.ukans.edu/cwis/writeups/misc/emacsguide.html}

@node Learning how to do something, Getting a printed manual, Basic editing, Getting help
@section How do I find out how to do something in Emacs?
@cindex Help for Emacs
@cindex Learning to do something in Emacs
@cindex Reference card for Emacs
@cindex Overview of help systems

There are several methods for finding out how to do things in Emacs.

@itemize @bullet

@item
The complete text of the Emacs manual is available on-line via the Info
hypertext reader.  Type @kbd{C-h i} to invoke Info.  Typing @key{h}
immediately after entering Info will provide a short tutorial on how to
use it.

@item
You can order a hardcopy of the manual from the FSF.  @xref{Getting a
printed manual}.

@item
You can get a printed reference card listing commands and keys to
invoke them.  You can order one from the FSF for $1 (or 10 for $5),
or you can print your own from the @file{etc/refcard.tex} or
@file{etc/refcard.ps} files in the Emacs distribution.

@item
You can list all of the commands whose names contain a certain word
(actually which match a regular expression) using @kbd{C-h a} (@kbd{M-x
command-apropos}).

@item
You can list all of the functions and variables whose names contain a
certain word using @kbd{M-x apropos}.

@item
There are many other commands in Emacs for getting help and
information.  To get a list of these commands, type @samp{?} after
@kbd{C-h}.

@end itemize

@node Getting a printed manual, Emacs Lisp documentation, Learning how to do something, Getting help
@section How do I get a printed copy of the Emacs manual?
@cindex Printed Emacs manual, obtaining
@cindex Manual, obtaining a printed copy of
@cindex Emacs manual, obtaining a printed copy of

You can order a printed copy of the Emacs manual from the FSF.  For
details see the file @file{etc/ORDERS}.

The full @TeX{} source for the manual also comes in the @file{man}
directory of the Emacs distribution, if you're daring enough to try to
print out this 440-page manual yourself (@pxref{Printing a Texinfo
file}).

If you absolutely have to print your own copy, and you don't have @TeX{},
you can get a PostScript version from

@uref{http://www.gnu.org/manual/emacs/ps/emacs.ps.gz}

A WWW version of the manual is at

@uref{www.gnu.org/manual/emacs/index.html}

@xref{Learning how to do something}, for how to view the manual on-line.

@node Emacs Lisp documentation, Installing Texinfo documentation, Getting a printed manual, Getting help
@section Where can I get documentation on Emacs Lisp?
@cindex Documentation on Emacs Lisp
@cindex Function documentation
@cindex Variable documentation
@cindex Emacs Lisp Reference Manual
@cindex Reference manual for Emacs Lisp

Within Emacs, you can type @kbd{C-h f} to get the documentation for a
function, @kbd{C-h v} for a variable.

For more information, obtain the Emacs Lisp Reference Manual.  Details on
ordering it from FSF are in file @file{etc/ORDERS}.

The Emacs Lisp Reference Manual is also available on-line, in Info
format.  Texinfo source for the manual (along with pregenerated Info
files) is available at

@uref{ftp://ftp.gnu.org/pub/gnu/emacs/elisp-manual-20-2.5.tar.gz}

and all mirrors of @samp{ftp.gnu.org} (@pxref{Current GNU distributions} for a
list).  @xref{Installing Texinfo documentation}, if you want to install
the Info files, or @ref{Printing a Texinfo file} if you want to use the
Texinfo source to print the manual yourself.

A WWW version of the Emacs Lisp Reference Manual is available at

@uref{http://www.gnu.org/manual/elisp-manual-20-2.5/elisp.html}

@node Installing Texinfo documentation, Printing a Texinfo file, Emacs Lisp documentation, Getting help
@section How do I install a piece of Texinfo documentation?
@cindex Texinfo documentation, installing
@cindex Installing Texinfo documentation
@cindex New Texinfo files, installing
@cindex Documentation, installing new Texinfo files

First, you must turn the Texinfo files into Info files.  You may do this
using the stand-alone @file{makeinfo} program, available as part of the latest
Texinfo package at

@uref{ftp://ftp.gnu.org/pub/gnu/texinfo/texinfo-3.12.tar.gz}

and all mirrors of @samp{ftp.gnu.org} (@pxref{Current GNU distributions} for a list).

For information about the Texinfo format, read the Texinfo manual which
comes with Emacs.  This manual also comes installed in Info format, so
you can read it on-line.

Neither @code{texinfo-format-buffer} nor @file{makeinfo} installs the
resulting Info files in Emacs's Info tree.  To install Info files:

@enumerate

@item Move the files to the @file{info} directory in the installed Emacs
 distribution.  @xref{Filename conventions}, if you don't know where that is.

@item Edit the file @file{info/dir} in the installed Emacs distribution,
 and add a line for the top level node in the Info package that you are
 installing.  Follow the examples already in this file.  The format is:

@example
* Topic: (relative-pathname).  Short description of topic.
@end example

@end enumerate 

If you want to install Info files and you don't have the necessary
privileges, you have several options:

@itemize @bullet

@item
Info files don't actually need to be installed before being used.  You
can feed a file name to the @code{Info-goto-node} command (invoked by
pressing @key{g} in Info mode) by typing the name of the file in
parentheses.  This goes to the node named "Top" in that file.  For
example, to view a Info file named "XXX" in your home directory, you can
type this:

@lisp
C-h i g (~/XXX) @key{RET}
@end lisp

@item
You can create your own Info directory.  You can tell Emacs where the
Info directory is by adding its pathname to the value of the variable
@code{Info-default-directory-list}.  For example, to use a private Info
directory which is a subdirectory of your home directory named "Info",
you could put this in your @file{.emacs} file:

@lisp
(setq Info-default-directory-list
      (cons "~/Info" Info-default-directory-list))
@end lisp

You will need a top-level Info file named @file{dir} in this directory
which has everything the system dir file has in it, except it should
list only entries for Info files in that directory.  You might not need
it if all files in this directory were referenced by other @file{dir}
files.  The node lists from all @file{dir} files in
@code{Info-default-directory-list} are merged by the Info system.

@end itemize

@node Printing a Texinfo file, Viewing Info files outside of Emacs, Installing Texinfo documentation, Getting help
@section How do I print a Texinfo file?
@cindex Printing a Texinfo file
@cindex Texinfo file, printing

You can't get nicely printed output from Info files; you must still have
the original Texinfo source file for the manual you want to print.

Assuming you have @TeX{} installed on your system, follow these steps:

@enumerate

@item Make sure the first line of the Texinfo file looks like this:

@example
\input texinfo
@end example

 You may need to change @samp{texinfo} to the full pathname of the
 texinfo.tex file, which comes with Emacs as @samp{man/texinfo.tex} (or
 copy or link it into the current directory).

@item @code{tex XXX.texinfo}

@item @code{texindex XXX.??}

 The @samp{texindex} program comes with Emacs as @file{man/texindex.c}.

@item @code{tex XXX.texinfo}

@item Print the DVI file @file{XXX.dvi} in the normal way for printing DVI files at your site.

@end enumerate

To get more general instructions, retrieve the latest Texinfo package
(@pxref{Installing Texinfo documentation}).

@node Viewing Info files outside of Emacs, Informational files for Emacs, Printing a Texinfo file, Getting help
@section Can I view Info files without using Emacs?
@cindex Viewing Info files
@cindex Info file viewers
@cindex Alternative Info file viewers

Yes.  Here are some alternative programs:

@itemize @bullet

@item Info, a stand-alone version of the Info program, comes as part of the
Texinfo package.  @xref{Installing Texinfo documentation}, for details.

@item Xinfo, a stand-alone version of the Info program that runs under X
Windows.  You can get it at
@uref{ftp://ftp.gnu.org/pub/gnu/xinfo/xinfo-1.01.01.tar.gz} and all
mirrors of @samp{ftp.gnu.org} (@pxref{Current GNU distributions}  for a list).

@item Tkinfo, an Info viewer that runs under X Windows and uses Tcl/Tk.  You
can get Tkinfo at @uref{http://math-www.uni-paderborn.de/~axel/tkinfo/}.

@end itemize

@node Informational files for Emacs, Help installing Emacs, Viewing Info files outside of Emacs, Getting help
@section What informational files are available for Emacs?
@cindex Informational files included with Emacs
@cindex Files included with Emacs
@cindex @file{COPYING}, description of file
@cindex @file{DISTRIB}, description of file
@cindex @file{FAQ}, description of file
@cindex @file{FTP}, description of file
@cindex @file{GNU}, description of file
@cindex @file{INTERVIEW}, description of file
@cindex @file{LPF}, description of file
@cindex @file{MACHINES}, description of file
@cindex @file{MAILINGLISTS}, description of file
@cindex @file{NEWS}, description of file
@cindex @file{SERVICE}, description of file
@cindex @file{SUN-SUPPORT}, description of file

This isn't a frequently asked question, but it should be!  A variety of
informational files about Emacs and relevant aspects of the GNU project
are available for you to read.

The following files are available in the @file{etc} directory of the
Emacs distribution (@pxref{Filename conventions}  if you're not sure where that is).

@table @file

@item COPYING
Emacs General Public License

@item DISTRIB
Emacs Availability Information, including the popular "Free Software
Foundation Order Form"

@item FAQ
Emacs Frequently Asked Questions (You're reading it)

@item FTP
How to get GNU Software by Internet FTP or by UUCP

@item GNU
The GNU Manifesto

@item INTERVIEW
Richard Stallman discusses his public-domain UNIX-compatible software
system with BYTE editors

@item LPF
Why you should join the League for Programming Freedom

@item MACHINES
Status of Emacs on Various Machines and Systems

@item MAILINGLISTS
GNU Project Electronic Mailing Lists

@item NEWS
Emacs news, a history of user-visible changes

@item SERVICE
GNU Service Directory

@item SUN-SUPPORT
including "Using Emacstool with GNU Emacs"

@end table

Latest versions of the above files also available at

@uref{ftp://ftp.gnu.org/pub/gnu/GNUinfo/}

More GNU information, including back issues of the "GNU's Bulletin", are
at

@uref{http://www.gnu.org/bulletins/bulletins.html} and

@uref{http://www.cs.pdx.edu/~trent/gnu/gnu.html}

@node Help installing Emacs, Obtaining the FAQ, Informational files for Emacs, Getting help
@section Where can I get help in installing Emacs?
@cindex Installation help
@cindex Help installing Emacs

@xref{Installing Emacs}, for some basic installation hints, and question
83 if you have problems with the installation.

The file @file{etc/SERVICE} (@pxref{Filename conventions} if you're not
sure where that is) lists companies and individuals willing to sell you
help in installing or using Emacs.  An up-to-date version this file is
available on @samp{ftp.gnu.org} (@pxref{Informational files for Emacs}).

@node Obtaining the FAQ,  , Help installing Emacs, Getting help
@section Where can I get the latest version of this FAQ?
@cindex FAQ, obtaining the
@cindex Latest FAQ version, obtaining the
@cindex Retrieving the latest FAQ version
@cindex E-mail, retrieving the FAQ via
@cindex Web, reading the FAQ on the

The Emacs FAQ is available in several ways:

@itemize @bullet

@item
Inside of Emacs itself.  You can get it from selecting the "Emacs FAQ"
option from the "Help" menu at the top of any Emacs frame, or by typing
@kbd{C-h F} (@kbd{M-x view-emacs-FAQ}).

@item
Via USENET.  If you can read news, the FAQ should be available in your
news spool, in both the @uref{news:gnu.emacs.help} and
@uref{news:comp.emacs} newsgroups.  Every news reader should allow you
to read any news article that is still in the news spool, even if you
have read the article before.  You may need to read the instructions for
your news reader to discover how to do this.  In @file{rn}, this command
will do this for you at the article selection level:

@example
?GNU Emacs Frequently Asked Questions?rc:m
@end example

In Gnus, you should type @kbd{C-u C-x C-s} from the @file{*Summary*}
buffer or @kbd{C-u @key{SPC}} from the @file{*Newsgroup*} buffer to view
all articles in a newsgroup.

If the FAQ articles have expired and been deleted from your news spool,
it might (or might not) do some good to complain to your news
administrator, because the most recent FAQ should not expire for a
while.

@item Via HTTP or FTP.  You can always fetch the latest FAQ from

@uref{http://www.lerner.co.il/emacs/} and

@uref{ftp://ftp.lerner.co.il/pub/emacs/}

@item
In the Emacs distribution.  Since Emacs 18.56, the FAQ at the time
of release has been part of the Emacs distribution as @file{etc/FAQ}
(@pxref{Filename conventions}).

@item
Via the World Wide Web.  A hypertext version is available at

@uref{http://www.lerner.co.il/emacs/}

@item
Via anonymous ftp and e-mail from @file{rtfm.mit.edu} (and its mirror in
Europe), the main repository for FAQs and other items posted to
news.answers.  The Emacs FAQs are available at

@uref{ftp://rtfm.mit.edu/pub/usenet/comp.emacs/} and

@uref{ftp://ftp.uni-paderborn.de/pub/doc/FAQ/comp/emacs/}

If you do not have access to anonymous FTP, you can access the archives
using the @file{rtfm.mit.edu} mail server.  The Emacs FAQ can be
retrieved by sending mail to @email{mail-server@@rtfm.mit.edu} with a
blank subject and containing

@example
send usenet/news.answers/GNU-Emacs-FAQ/diffs
send usenet/news.answers/GNU-Emacs-FAQ/part1
send usenet/news.answers/GNU-Emacs-FAQ/part2
send usenet/news.answers/GNU-Emacs-FAQ/part3
send usenet/news.answers/GNU-Emacs-FAQ/part4
send usenet/news.answers/GNU-Emacs-FAQ/part5
@end example

For more information, send email to @email{mail-server@@rtfm.mit.edu}
with "help" and "index" in the body on separate lines.

@item
As the very last resort, you can e-mail a request to
@email{emacs-faq@@lerner.co.il}.  Don't do this unless you have made a
serious effort to obtain the FAQ list via one of the methods listed
above.

@end itemize

@c ------------------------------------------------------------
@node    Status of Emacs, Common requests, Getting help, Top
@chapter Status of Emacs
@cindex Status of Emacs

This section gives you basic information about Emacs, including its
latest version status.

@menu
* Origin of the term Emacs::    
* Latest version of Emacs::     
* New in Emacs 20::             
@end menu

@node Origin of the term Emacs, Latest version of Emacs, Status of Emacs, Status of Emacs
@section Where does the name "Emacs" come from?
@cindex Origin of the term "Emacs"
@cindex Emacs name origin
@cindex TECO
@cindex Original version of Emacs

Emacs originally was an acronym for Editor MACroS.  RMS says he "picked
the name Emacs because @key{E} was not in use as an abbreviation on ITS at
the time."  The first Emacs was a set of macros written in 1976 at MIT
by RMS for the editor TECO (Text Editor and COrrector, originally Tape
Editor and COrrector) under ITS on a PDP-10.  RMS had already extended
TECO with a "real-time" full screen mode with reprogrammable keys.
Emacs was started by @email{gls@@east.sun.com, Guy Steele} as a project
to unify the many divergent TECO command sets and key bindings at MIT,
and completed by RMS.

Many people have said that TECO code looks a lot like line noise; you
can read more at @uref{news:alt.lang.teco}.  Someone has written a TECO
implementation in Emacs Lisp (to find it, @ref{Packages that do not come
with Emacs}); it would be an interesting project to run the original
TECO Emacs inside of Emacs.

For some not-so-serious alternative reasons for Emacs to have that
name, check out @file{etc/JOKES} (@pxref{Filename conventions}).

@node Latest version of Emacs, New in Emacs 20, Origin of the term Emacs, Status of Emacs
@section What is the latest version of Emacs?
@cindex Version, latest
@cindex Latest version

Emacs 20.5 is the current version as of this writing.

@node New in Emacs 20,  , Latest version of Emacs, Status of Emacs
@section What is different about Emacs 20?
@cindex Differences between Emacs 19 and Emacs 20
@cindex Emacs 20, new features in
@cindex Recently introduced features

To find out what has changed in recent versions, type @kbd{C-h n}
(@kbd{M-x view-emacs-news}).  The oldest changes are at the bottom of
the file, so you might want to read it starting there, rather than at
the top.

The differences between Emacs versions 18 and 19 was rather dramatic;
the introduction of frames, faces, and colors on windowing systems was
obvious to even the most casual user.

There are differences between Emacs versions 19 and 20 as well, but many
are more subtle or harder to find.  Among the changes are the inclusion
of MULE code for languages that use non-Latin characters, the "customize"
facility for modifying variables without having to use Lisp, and
automatic conversion of files from Macintosh, Microsoft, and Unix
platforms.

A number of older Lisp packages, such as Gnus, Supercite and the
calendar/diary, have been updated and enhanced to work with Emacs 20,
and are now included with the standard distribution.


@c ------------------------------------------------------------
@node    Common requests, Bugs and problems, Status of Emacs, Top
@chapter Common requests
@cindex Common requests

@menu
* Setting up a customization file::  
* Debugging a customization file::  
* Displaying the current line or column::  
* Displaying the current filename in the titlebar::  
* Turning on abbrevs by default::  
* Turning on auto-fill by default::  
* Associating modes with files::  
* Working with unprintable characters::  
* Highlighting a region::       
* Controlling case sensitivity::  
* Wrapping words automatically::  
* Spell-checkers::              
* Checking TeX and *roff documents::  
* Changing load-path::          
* Using an already running Emacs process::  
* Compiler error messages::     
* Indenting switch statements::  
* Horizontal scrolling::        
* Overwrite mode::              
* Turning off beeping::         
* Turning the volume down::     
* Automatic indentation::       
* Matching parentheses::        
* Hiding #ifdef lines::         
* Repeating commands::          
* Valid X resources::           
* Evaluating Emacs Lisp code::  
* Changing the length of a Tab::  
* Inserting > at the beginning of each line::  
* Underlining paragraphs::      
* Repeating a command as many times as possible::  
* Forcing the cursor to remain in the same column::  
* Forcing Emacs to iconify itself::  
* Using regular expressions::   
* Replacing text across multiple files::  
* Documentation for etags::     
* Disabling backups::           
* Disabling auto-save-mode::    
* Modifying pull-down menus::   
* Deleting menus and menu options::  
* Turning on syntax highlighting::  
* Scrolling only one line::     
* Replacing highlighted text::  
* Editing MS-DOS files::        
* Filling paragraphs with a single space::  
@end menu

@node Setting up a customization file, Debugging a customization file, Common requests, Common requests
@section How do I set up a @file{.emacs} file properly?
@cindex @file{.emacs} file, setting up
@cindex Init file, setting up
@cindex Customization file, setting up

@inforef{Init File, Init File, emacs}

In general, new Emacs users should not have @file{.emacs} files, because
it causes confusing non-standard behavior.  Then they send questions to
@email{help-gnu-emacs@@gnu.org} asking why Emacs isn't behaving as
documented.

Emacs 20 includes the new @code{customize} facility, which can be
invoked using @kbd{M-x customize @key{RET}}.  This allows users who are
unfamiliar with Emacs Lisp to modify their @file{.emacs} files in a
relatively straightforward way, using menus rather than Lisp code.  Not
all packages support Customize as of this writing, but the number is
growing fairly steadily.

While @code{customize} might indeed make it easier to configure Emacs,
consider taking a bit of time to learn Emacs Lisp and modifying your
@file{.emacs} directly. Simple configuration options are described
rather completely in @inforef{Init File, Init File, emacs}, for users
interested in performing frequently requested, basic tasks.

@node Debugging a customization file, Displaying the current line or column, Setting up a customization file, Common requests
@section How do I debug a @file{.emacs} file?
@cindex Debugging @file{.emacs} file
@cindex @file{.emacs} debugging
@cindex Init file debugging
@cindex @samp{-debug-init}

Start Emacs with the @samp{-debug-init} command-line option.  This
enables the Emacs Lisp debugger before evaluating your @file{.emacs}
file, and places you in the debugger if something goes wrong.  The top
line in the @file{trace-back} buffer will be the error message, and the
second or third line of that buffer will display the Lisp code from your
@file{.emacs} file that caused the problem.

You can also evaluate an individual function or argument to a function
in your @file{.emacs} file by moving the cursor to the end of the
function or argument and typing @kbd{C-x C-e} (@kbd{M-x
eval-last-sexp}).

Use @kbd{C-h v} (@kbd{M-x describe-variable}) to check the value of
variables which you are trying to set or use.

@node Displaying the current line or column, Displaying the current filename in the titlebar, Debugging a customization file, Common requests
@section How do I make Emacs display the current line (or column) number?
@cindex @code{line-number-mode}
@cindex Displaying the current line or column
@cindex Line number, displaying the current
@cindex Column, displaying the current
@cindex @code{mode-line-format}

To have Emacs automatically display the current line number of the point
in the mode line, do @kbd{M-x line-number-mode}.  You can also put the
form

@lisp
(setq line-number-mode t)
@end lisp

in your @file{.emacs} file to achieve this whenever you start Emacs.
Note that Emacs will not display the line number if the buffer is larger
than the value of the variable @code{line-number-display-limit}.

As of Emacs 20, you can similarly display the current column with
@kbd{M-x column-number-mode}, or by putting the form

@lisp
(setq column-number-mode t) 
@end lisp

in your @file{.emacs} file.

The "%c" format specifier in the variable @code{mode-line-format} will
insert the current column's value into the mode line.  See the
documentation for @code{mode-line-format} (using @kbd{C-h v
mode-line-format @key{RET}}) for more information on how to set and use
this variable.

Users of all Emacs versions can display the current column using
@email{abraham@@iesd.auc.dk, Per Abrahamsen's} "column" package.
@xref{Packages that do not come with Emacs}, for instructions on how to
get it.

None of the vi emulation modes provide the "set number" capability of vi
(as far as we know).

@node Displaying the current filename in the titlebar, Turning on abbrevs by default, Displaying the current line or column, Common requests
@section How can I modify the titlebar to contain the current filename?
@cindex Titlebar, displaying the current filename in
@cindex Filename, displaying in the titlebar
@cindex @code{frame-title-format}

The contains of an Emacs frame's titlebar is controlled by the variable
@code{frame-title-format}, which has the same structure as the variable
@code{mode-line-format}.  (Use @kbd{C-h v} or @kbd{M-x
describe-variable} to get information about one or both of these
variables.)

By default, the titlebar for a frame does contain the name of the buffer
currently being visited, except if there is a single frame.  In such a
case, the titlebar contains the name of the user and the machine at
which Emacs was invoked.  This is done by setting
@code{frame-title-format} to the default value of

@lisp
(multiple-frames "%b" ("" invocation-name "@@" system-name))
@end lisp

To modify the behavior such that frame titlebars contain the buffer's
name regardless of the number of existing frames, include the following
in your @file{.emacs}:

@lisp
(setq frame-title-format "%b")
@end lisp

@node Turning on abbrevs by default, Turning on auto-fill by default, Displaying the current filename in the titlebar, Common requests
@section How do I turn on abbrevs by default just in mode XXX?
@cindex Abbrevs, turning on by default

Put this in your @file{.emacs} file:

@lisp
(condition-case ()
   (quietly-read-abbrev-file)
  (file-error nil))

(add-hook 'XXX-mode-hook
          (lambda ()
           (setq abbrev-mode t)))
@end lisp

@node Turning on auto-fill by default, Associating modes with files, Turning on abbrevs by default, Common requests
@section How do I turn on @code{auto-fill-mode} by default?
@cindex @code{auto-fill-mode}, activating automatically
@cindex Filling automatically
@cindex Automatic entry to @code{auto-fill-mode}

To turn on @code{auto-fill-mode} just once for one buffer, use @kbd{M-x
auto-fill-mode}.

To turn it on for every buffer in a certain mode, you must use the hook
for that mode.  For example, to turn on @code{auto-fill} mode for all
text buffers, including the following in your @file{.emacs} file:

@lisp
(add-hook 'text-mode-hook 'turn-on-auto-fill)
@end lisp

If you want @code{auto-fill} mode on in all major modes, do this:

@lisp
(setq-default auto-fill-function 'do-auto-fill)
@end lisp

@node Associating modes with files, Working with unprintable characters, Turning on auto-fill by default, Common requests
@section How do I make Emacs use a certain major mode for certain files?
@cindex Associating modes with files
@cindex File extensions and modes
@cindex @code{auto-mode-alist}, modifying
@cindex Modes, associating with file extensions

If you want to use XXX mode for all files which end with the extension
@samp{.YYY}, this will do it for you:

@lisp
(setq auto-mode-alist (cons '("\\.YYY\\'" . XXX-mode) auto-mode-alist))
@end lisp

Otherwise put this somewhere in the first line of any file you want to
edit in XXX mode (in the second line, if the first line begins with
@samp{#!}):

@example
-*-XXX-*-
@end example

Beginning with Emacs 19, the variable @code{interpreter-mode-alist}
specifies which mode to use when loading a shell script.  (Emacs
determines which interpreter you're using by examining the first line of
the file.)  This feature only applies when the file name doesn't
indicate which mode to use.  Use @kbd{C-h v} (or @kbd{M-x
describe-variable}) on @code{interpreter-mode-alist} to learn more.

@node Working with unprintable characters, Highlighting a region, Associating modes with files, Common requests
@section How do I search for, delete, or replace unprintable (eight-bit or control) characters?
@cindex Unprintable characters, working with
@cindex Working with unprintable characters
@cindex Control characters, working with
@cindex Eight-bit characters, working with
@cindex Searching for unprintable characters
@cindex Regexps and unprintable characters

To search for a single character that appears in the buffer as, for
example, @samp{\237}, you can type @kbd{C-s C-q 2 3 7}.  (This assumes
the value of @code{search-quote-char} is 17 (i.e., @kbd{C-q}).)
Searching for ALL unprintable characters is best done with a regular
expression ("regexp") search.  The easiest regexp to use for the
unprintable chars is the complement of the regexp for the printable
chars.

@itemize @bullet

@item
Regexp for the printable chars: @samp{[\t\n\r\f -~]}

@item
Regexp for the unprintable chars: @samp{[^\t\n\r\f -~]}

@end itemize

To type these special characters in an interactive argument to
@code{isearch-forward-regexp} or @code{re-search-forward}, you need to
use @kbd{C-q}.  (@samp{\t}, @samp{\n}, @samp{\r}, and @samp{\f} stand
respectively for @key{TAB}, @key{LFD}, @key{RET}, and @kbd{C-l}.)  So,
to search for unprintable characters using @code{re-search-forward}:

@kbd{M-x re-search-forward @key{RET} [^ @key{TAB} C-q @key{LFD} C-q @key{RET} C-q C-l @key{SPC} -~] @key{RET}}

Using @code{isearch-forward-regexp}:

@kbd{M-C-s [^ @key{TAB} @key{RET} C-q @key{RET} C-q C-l @key{SPC} -~]}

To delete all unprintable characters, simply use replace-regexp:

@kbd{M-x replace-regexp @key{RET} [^ @key{TAB} C-q @key{LFD} C-q @key{RET} C-q C-l @key{SPC} -~] @key{RET} @key{RET}}

Replacing is similar to the above.  To replace all unprintable
characters with a colon, use:

M-x replace-regexp @key{RET} [^ @key{TAB} C-q @key{LFD} C-q @key{RET} C-q C-l @key{SPC} -~] @key{RET} : @key{RET}

@itemize @bullet

@item You don't need to quote @key{TAB} with either isearch or typing
something in the minibuffer.

@end itemize

@node Highlighting a region, Controlling case sensitivity, Working with unprintable characters, Common requests
@section How can I highlight a region of text in Emacs?
@cindex Highlighting text
@cindex Text, highlighting
@cindex @code{transient-mark-mode}
@cindex Region, highlighting a

If you are using a windowing system such as X, you can cause the region
to be highlighted when the mark is active by including

@lisp
(transient-mark-mode t)
@end lisp

in your @file{.emacs} file.  (Also see @xref{Turning on syntax highlighting}.)

@node Controlling case sensitivity, Wrapping words automatically, Highlighting a region, Common requests
@section How do I control Emacs's case-sensitivity when searching/replacing?
@cindex @code{case-fold-search}
@cindex Case sensitivity of searches
@cindex @code{case-replace}
@cindex Searching without case sensitivity
@cindex Ignoring case in searches

For searching, the value of the variable @code{case-fold-search}
determines whether they are case sensitive:

@lisp
(setq case-fold-search nil) ; make searches case sensitive
(setq case-fold-search t)   ; make searches case insensitive
@end lisp

Similarly, for replacing the variable @code{case-replace} determines
whether replacements preserve case.

To change the case sensitivity just for one major mode, use the major
mode's hook.  For example:

@lisp
(add-hook 'XXX-mode-hook
          (lambda ()
           (setq case-fold-search nil)))
@end lisp

@node Wrapping words automatically, Spell-checkers, Controlling case sensitivity, Common requests
@section How do I make Emacs wrap words for me?
@cindex Wrapping word automatically
@cindex @code{auto-fill-mode}, introduction to
@cindex Maximum line width, default value
@cindex @code{fill-column}, default value

Use @code{auto-fill-mode}, activated by typing @kbd{M-x auto-fill-mode}.
The default maximum line width is 70, determined by the variable
@code{fill-column}.  To learn how to turn this on automatically, @pxref{Turning on auto-fill by default}.

@node Spell-checkers, Checking TeX and *roff documents, Wrapping words automatically, Common requests
@section Where can I get a better spelling checker for Emacs?
@cindex Checking spelling
@cindex Spelling, checking text documents

Use Ispell.  @xref{Ispell}.

@node Checking TeX and *roff documents, Changing load-path, Spell-checkers, Common requests
@section How can I spell-check @TeX{} or *roff documents?
@cindex Spelling, checking @TeX{} documents
@cindex @TeX{} documents, checking spelling in

Use Ispell.  Ispell can handle @TeX{} and *roff documents.
@xref{Ispell}.

@node Changing load-path, Using an already running Emacs process, Checking TeX and *roff documents, Common requests
@section How do I change @code{load-path}?
@cindex @code{load-path}, modifying
@cindex Modifying @code{load-path}
@cindex Adding to @code{load-path}

In general, you should only add to the @code{load-path}.  You can add
directory @var{/XXX/YYY} to the load path like this:

@lisp
(setq load-path (cons "/XXX/YYY/" load-path))
@end lisp

To do this relative to your home directory:

@lisp
(setq load-path (cons "~/YYY/" load-path)
@end lisp

@node Using an already running Emacs process, Compiler error messages, Changing load-path, Common requests
@section How do I use an already running Emacs from another window?
@cindex @code{emacsclient}
@cindex Emacs server functions
@cindex Using an existing Emacs process

@code{emacsclient}, which comes with Emacs, is for editing a file using
an already running Emacs rather than starting up a new Emacs.  It does
this by sending a request to the already running Emacs, which must be
expecting the request.

@itemize @bullet

@item
Setup

Emacs must have executed the @code{server-start} function for
@samp{emacsclient} to work.  This can be done either by a command line
option:

@example
emacs -f server-start
@end example

or by invoking @code{server-start} from @file{.emacs}:

@lisp
(if (some conditions are met) (server-start))
@end lisp

When this is done, Emacs starts a subprocess running a program called
@samp{server}.  @samp{server} creates a Unix domain socket.  The socket
is either named @file{.emacs_server}, in the user's home directory,
or @file{esrv-@var{USER-ID}-@var{SYSTEM-NAME}}, in the @file{/tmp}
directory, depending on how @samp{emacsserver} was compiled.

To get your news reader, mail reader, etc., to invoke
@samp{emacsclient}, try setting the environment variable @code{EDITOR}
(or sometimes @code{VISUAL}) to the value @samp{emacsclient}.  You may
have to specify the full pathname of the @samp{emacsclient} program
instead.  Examples:

@example
# csh commands:
setenv EDITOR emacsclient

# using full pathname
setenv EDITOR /usr/local/emacs/etc/emacsclient  

# sh command:
EDITOR=emacsclient ; export EDITOR
@end example

@item Normal use

When @samp{emacsclient} is run, it connects to the @file{.emacs_server}
socket and passes its command line options to @samp{server}.  When
@samp{server} receives these requests, it sends this information on the
the Emacs process, which at the next opportunity will visit the files
specified.  (Line numbers can be specified just like with Emacs.)  The
user will have to switch to the Emacs window by hand.  When the user is
done editing a file, the user can type @kbd{C-x #} (or @kbd{M-x
server-edit}) to indicate this.  If there is another buffer requested by
emacsclient, Emacs will switch to it; otherwise emacsclient will exit,
signaling the calling program to continue.

@samp{emacsclient} and @samp{server} must be running on machines which
share the same filesystem for this to work.  The pathnames that
@samp{emacsclient} specifies should be correct for the filesystem that
the Emacs process sees.  The Emacs process should not be suspended at
the time @samp{emacsclient} is invoked.  @samp{emacsclient} should
either be invoked from another X window or from a shell window inside
Emacs itself.

There is an enhanced version of @samp{emacsclient}/server called
@samp{gnuserv} by @email{ange@@hplb.hpl.hp.com, Andy Norman} which is
available in the Emacs Lisp Archive (@pxref{Packages that do not come
with Emacs}).  @samp{gnuserv} uses Internet domain sockets, so it can
work across most network connections.  It also supports the execution of
arbitrary Emacs Lisp forms and does not require the client program to
wait for completion.

The alpha version of an enhanced @samp{gnuserv} is available
at

@uref{ftp://ftp.wellfleet.com/netman/psmith/emacs/gnuserv-2.1alpha.tar.gz}

@end itemize

@node Compiler error messages, Indenting switch statements, Using an already running Emacs process, Common requests
@section How do I make Emacs recognize my compiler's funny error messages?
@cindex Compiler error messages, recognizing
@cindex Recognizing non-standard compiler errors
@cindex Regexps for recognizing compiler errors
@cindex Errors, recognizing compiler

The variable @code{compilation-error-regexp-alist} helps control how
Emacs parses your compiler output.  It is a list of triples of the form:
@code{(@var{regexp} @var{file-idx} @var{line-idx})}, where @var{regexp}, @var{file-idx} and
@var{line-idx} are strings.  To help determine what the constituent
elements should be, load @file{compile.el} and then use @kbd{C-h v
compilation-error-regexp-alist @key{RET}}

to see the current value.  A good idea is to look at @file{compile.el}
itself as the comments included for this variable are quite useful ---
the regular expressions required for your compiler's output may be very
close to one already provided.  Once you have determined the proper
regexps, use the following to inform Emacs of your changes:

@lisp
(setq compilation-error-regexp-alist
      (cons '(REGEXP FILE-IDX LINE-IDX)
         compilation-error-regexp-alist))
@end lisp

@node Indenting switch statements, Horizontal scrolling, Compiler error messages, Common requests
@section How do I change the indentation for @code{switch}?
@cindex @code{switch}, indenting
@cindex Indenting of @code{switch}

Many people want to indent their @code{switch} statements like this:

@example
f()
@{
  switch(x) @{
    case A:
      x1;
      break;
    case B:
      x2;
      break;
    default:
      x3;
  @}
@}
@end example

The solution at first appears to be: set @code{c-indent-level} to 4 and
@code{c-label-offset} to -2.  However, this will give you an indentation
spacing of four instead of two.

The solution is to use @code{cc-mode} (the default mode for C
programming in Emacs 20) and add the following line:

@lisp
(c-set-offset 'case-label '+)
@end lisp

There appears to be no way to do this with the old @code{c-mode}.

@node Horizontal scrolling, Overwrite mode, Indenting switch statements, Common requests
@section How can I make Emacs automatically scroll horizontally?
@cindex @code{hscroll-mode}
@cindex Horizontal scrolling
@cindex Scrolling horizontally

Use @code{hscroll-mode}, included in Emacs 20.  Here is some information from
the documentation, available by typing @kbd{C-h f hscroll-mode @key{RET}}:

Automatically scroll horizontally when the point moves off the
left or right edge of the window.  

@itemize @minus

@item Type @kbd{M-x hscroll-mode} to enable it in the current buffer.
@item Type @kbd{M-x hscroll-global-mode} to enable it in every buffer.
@item @code{turn-on-hscroll} is useful in mode hooks as in:

@lisp
(add-hook 'text-mode-hook 'turn-on-hscroll)
@end lisp

@item @code{hscroll-margin} controls how close the cursor can get to the
edge of the window. 

@item @code{hscroll-step-percent} controls how far to jump once we decide to do so.

@end itemize

@node Overwrite mode, Turning off beeping, Horizontal scrolling, Common requests
@section How do I make Emacs "typeover" or "overwrite" instead of inserting?
@cindex @key{Insert}
@cindex @code{overwrite-mode}
@cindex Overwriting existing text
@cindex Toggling @code{overwrite-mode}

@kbd{M-x overwrite-mode} (a minor mode).  This toggles
@code{overwrite-mode} on and off, so exiting from @code{overwrite-mode}
is as easy as another @kbd{M-x overwrite-mode}.

On some workstations, @key{Insert} toggles @code{overwrite-mode} on and off.

@node Turning off beeping, Turning the volume down, Overwrite mode, Common requests
@section How do I stop Emacs from beeping on a terminal?
@cindex Beeping, turning off
@cindex Visible bell
@cindex Bell, visible

@email{martin@@cc.gatech.edu, Martin R. Frank} writes:

Tell Emacs to use the "visible bell" instead of the audible bell, and
set the visible bell to nothing.

That is, put the following in your @code{TERMCAP} environment variable
(assuming you have one):

@example
... :vb=: ...                    
@end example

And evaluate the following Lisp form:

@example
(setq visible-bell t)
@end example

@node Turning the volume down, Automatic indentation, Turning off beeping, Common requests
@section How do I turn down the bell volume in Emacs running under X Windows?
@cindex Bell, volume of
@cindex Volume of bell

You can adjust the bell volume and duration for all programs with the
shell command @file{xset}.

Invoking @file{xset} without any arguments produces some basic information,
including the following:

@example
usage:  xset [-display host:dpy] option ...
  To turn bell off:
      -b                b off               b 0
  To set bell volume, pitch and duration:
       b [vol [pitch [dur]]]          b on
@end example

@node Automatic indentation, Matching parentheses, Turning the volume down, Common requests
@section How do I tell Emacs to automatically indent a new line to the indentation of the previous line?
@cindex Indenting new lines
@cindex New lines, indenting of
@cindex Previous line, indenting according to

Such behavior is automatic in Emacs 20.  From the NEWS file for Emacs
20.2:

@example
** In Text mode, now only blank lines separate paragraphs.  This makes
it possible to get the full benefit of Adaptive Fill mode in Text mode,
and other modes derived from it (such as Mail mode).  @key{TAB} in Text
mode now runs the command @code{indent-relative}; this makes a practical
difference only when you use indented paragraphs.

As a result, the old Indented Text mode is now identical to Text mode,
and is an alias for it.

If you want spaces at the beginning of a line to start a paragraph, use
the new mode, Paragraph Indent Text mode.
@end example

If you have @code{auto-fill-mode} on (@pxref{Turning on auto-fill by
default}), you can tell Emacs to prefix every line with a certain
character sequence, the "fill prefix."  Type the prefix at the beginning
of a line, position point after it, and then type @kbd{C-x .}
(@code{set-fill-prefix}) to set the fill prefix.  Thereafter,
auto-filling will automatically put the fill prefix at the beginning of
new lines, and @kbd{M-q} (@code{fill-paragraph}) will maintain any fill
prefix when refilling the paragraph.

If you have paragraphs with different levels of indentation, you will
have to set the fill prefix to the correct value each time you move to a
new paragraph.  To avoid this hassle, try one of the many packages
available from the Emacs Lisp Archive (@pxref{Packages that do not come
with Emacs}.)  Look up "fill" and "indent" in the Lisp Code Directory
for guidance.

@node Matching parentheses, Hiding #ifdef lines, Automatic indentation, Common requests
@section How do I show which parenthesis matches the one I'm looking at?
@cindex Parentheses, matching
@cindex @file{paren.el}
@cindex Highlighting matching parentheses
@cindex Pairs of parentheses, highlighting
@cindex Matching parentheses

As of version 19, Emacs comes with @file{paren.el}, which (when loaded)
will automatically highlight matching parentheses whenever point (i.e.,
the cursor) is located over one.  To load @file{paren.el} automatically,
include the line

@lisp
(require 'paren)
@end lisp

in your @file{.emacs} file.  @email{shutkoa@@ugsolutions.com, Alan Shutko}
reports that as of version 20.1, you must also call @code{show-paren-mode} in
your @file{.emacs} file:

@lisp
(show-paren-mode 1)
@end lisp

@code{customize} will let you turn on @code{show-paren-mode}.  Use
@kbd{M-x customize-group @key{RET} paren-showing @key{RET}}.  From
within @code{customize}, you can also go directly to the "paren-showing"
group.

  Alternatives to paren include:

@itemize @bullet

@item
If you're looking at a right parenthesis (or brace or bracket) you can
delete it and reinsert it.  Emacs will blink the cursor on the matching
parenthesis.

@item
@kbd{M-C-f} (@code{forward-sexp}) and @kbd{M-C-b} (@code{backward-sexp})
will skip over one set of balanced parentheses, so you can see which
parentheses match.  (You can train it to skip over balanced brackets
and braces at the same time by modifying the syntax @key{TAB}le.)

@item
Here is some Emacs Lisp that will make the @key{%} key show the matching
parenthesis, like in vi.  In addition, if the cursor isn't over a
parenthesis, it simply inserts a % like normal.

@lisp
;; By an unknown contributor

(global-set-key "%" 'match-paren)

(defun match-paren (arg)
  "Go to the matching paren if on a paren; otherwise insert %."
  (interactive "p")
  (cond ((looking-at "\\s\(") (forward-list 1) (backward-char 1))
        ((looking-at "\\s\)") (forward-char 1) (backward-list 1))
        (t (self-insert-command (or arg 1)))))
@end lisp

@end itemize

@node Hiding #ifdef lines, Repeating commands, Matching parentheses, Common requests
@section In C mode, can I show just the lines that will be left after @code{#ifdef} commands are handled by the compiler?
@cindex @code{#ifdef}, selective display of
@cindex @code{hide-ifdef-mode}
@cindex Hiding @code{#ifdef} text
@cindex Selectively displaying @code{#ifdef} code

@kbd{M-x hide-ifdef-mode}.  (This is a minor mode.)  You might also want
to try @file{cpp.el}, available at the Emacs Lisp Archive
(@pxref{Packages that do not come with Emacs}).

@node Repeating commands, Valid X resources, Hiding #ifdef lines, Common requests
@section Is there an equivalent to the @code{.} (dot) command of vi?
@cindex Repeating commands as with vi
@cindex Command, repeat last
@cindex @code{.}, equivalent to vi command

(@code{.} is the redo command in vi.  It redoes the last insertion/deletion.)

As of Emacs 20.3, there is indeed a @code{repeat} command (@kbd{C-x .})
that repeats the last command.  If you preface it with a prefix
argument, the prefix arg is applied to the command.

You can also type @kbd{C-x @key{ESC} @key{ESC}}
(@code{repeat-complex-command}) to reinvoke commands that used the
minibuffer to get arguments.  In @code{repeat-complex-command} you can
type @kbd{M-p} and @kbd{M-n} to scan through all the different complex
commands you've typed.

To repeat a set of commands, use keyboard macros.  (@inforef{Keyboard
Macros, Keyboard Macros, emacs}.)

If you're really desperate for the @code{.} command, use VIPER, which comes
with Emacs, and which appears to support it.  (@xref{VIPER}.)

@node Valid X resources, Evaluating Emacs Lisp code, Repeating commands, Common requests
@section What are the valid X resource settings (i.e., stuff in .Xdefaults)?
@cindex Resources, X
@cindex X resources
@cindex Setting X resources

@inforef{Resources X, Resources X, emacs}.

You can also use a resource editor, such as editres (for X11R5 and
onwards), to look at the resource names for the menu bar, assuming Emacs
was compiled with the X toolkit.

@node Evaluating Emacs Lisp code, Changing the length of a Tab, Valid X resources, Common requests
@section How do I execute ("evaluate") a piece of Emacs Lisp code?
@cindex Evaluating Lisp code
@cindex Lisp forms, evaluating

There are a number of ways to execute ("evaluate," in Lisp lingo) an
Emacs Lisp "form":

@itemize @bullet

@item
If you want it evaluated every time you run Emacs, put it in a file
named @file{.emacs} in your home directory.  This is known as your ".emacs
file," and contains all of your personal customizations.

@item
You can type the form in the @file{*scratch*} buffer, and then type
@key{LFD} (or @kbd{C-j}) after it.  The result of evaluating the form
will be inserted in the buffer.

@item
In @code{emacs-lisp-mode}, typing @kbd{M-C-x} evaluates a top-level form
before or around point.

@item
Typing @kbd{C-x C-e} in any buffer evaluates the Lisp form immediately
before point and prints its value in the echo area.

@item
Typing @kbd{M-:} or @kbd{M-x eval-expression} allows you to type a Lisp
form in the minibuffer which will be evaluated.

@item
You can use @kbd{M-x load-file} to have Emacs evaluate all the Lisp
forms in a file.  (To do this from Lisp use the function @code{load}
instead.)

The functions @code{load-library}, @code{eval-region},
@code{eval-current-buffer}, @code{require}, and @code{autoload} are also
useful; @pxref{Emacs Lisp documentation} if you want to learn more about
them.

@end itemize

@node Changing the length of a Tab, Inserting > at the beginning of each line, Evaluating Emacs Lisp code, Common requests
@section How do I change Emacs's idea of the @key{TAB} character's length?
@cindex Tab length
@cindex Length of tab character
@cindex @code{default-tab-width} 

Set the variable @code{default-tab-width}.  For example, to set
@key{TAB} stops every 10 characters, insert the following in your
@file{.emacs} file:

@lisp
(setq default-tab-width 10)
@end lisp

Do not confuse variable @code{tab-width} with variable
@code{tab-stop-list}.  The former is used for the display of literal
@key{TAB} characters.  The latter controls what characters are inserted
when you press the @key{TAB} character in certain modes.

@node Inserting > at the beginning of each line, Underlining paragraphs, Changing the length of a Tab, Common requests
@section How do I insert @samp{>} at the beginning of every line?
@cindex Prefix character, inserting in mail/news replies
@cindex Replies to mail/news, inserting a prefix character
@cindex @code{mail-yank-prefix}
@cindex Mail replies, inserting a prefix character
@cindex News replies, inserting a prefix character

To do this to an entire buffer, type @kbd{M-< M-x replace-regexp
@key{RET} ^ @key{RET} > @key{RET}}.

To do this to a region, use @code{string-rectangle} (@kbd{C-x r t}).
Set the mark (@kbd{C-@key{SPC}}) at the beginning of the first line you
want to prefix, move the cursor to last line to be prefixed, and type
@kbd{C-x r t > @key{RET}}.  To do this for the whole buffer, type
@kbd{C-x h C-x r t > @key{RET}}.

If you are trying to prefix a yanked mail message with @samp{>}, you
might want to set the variable @code{mail-yank-prefix}.  Better yet, get
the Supercite package (@pxref{Supercite}), which provides flexible
citation for yanked mail and news messages.  @xref{Changing the included
text prefix}, for additional information.

@node Underlining paragraphs, Repeating a command as many times as possible, Inserting > at the beginning of each line, Common requests
@section How do I insert "_^H" before each character in a region to get an underlined paragraph?
@cindex Underlining a region of text
@cindex @code{underline-region}

@kbd{M-x underline-region}.

@node Repeating a command as many times as possible, Forcing the cursor to remain in the same column, Underlining paragraphs, Common requests
@section How do I repeat a command as many times as possible?
@cindex Repeating commands
@cindex Commands, repeating

Use @kbd{C-x (} and @kbd{C-x )} to make a keyboard macro that invokes
the command and then type @kbd{M-0 C-x e}.

Any messages your command prints in the echo area will be suppressed.

@node Forcing the cursor to remain in the same column, Forcing Emacs to iconify itself, Repeating a command as many times as possible, Common requests
@section How do I make Emacs behave like this: when I go up or down, the cursor should stay in the same column even if the line is too short?
@cindex @code{picture-mode}
@cindex Remaining in the same column, regardless of contents
@cindex Vertical movement in empty documents

@kbd{M-x picture-mode}.

@node Forcing Emacs to iconify itself, Using regular expressions, Forcing the cursor to remain in the same column, Common requests
@section How do I tell Emacs to iconify itself?
@cindex Iconification under X Windows
@cindex X Windows and iconification
@cindex Suspending Emacs

@kbd{C-z} iconifies Emacs when running under X Windows and suspends Emacs
otherwise.  @inforef{Misc X, Misc X, emacs}.

@node Using regular expressions, Replacing text across multiple files, Forcing Emacs to iconify itself, Common requests
@section How do I use regexps (regular expressions) in Emacs?
@cindex Regexps
@cindex Regular expressions
@cindex Differences between Unix and Emacs regexps
@cindex Unix regeps, differences from Emacs
@cindex Text strings, putting regexps in

@inforef{Regexps, Regexps, emacs}.

The "or" operator is @samp{\|}, not @samp{|}, and the grouping operators
are @samp{\(} and @samp{\)}.  Also, the string syntax for a backslash is
@samp{\\}.  To specify a regular expression like @samp{xxx\(foo\|bar\)}
in a Lisp string, use @samp{xxx\\(foo\\|bar\\)}.

Notice the doubled backslashes!

@itemize @bullet

@item Unlike in Unix @file{grep}, @file{sed}, etc., a complement
character set (@samp{[^...]})  can match a newline character (@key{LFD}
aka @kbd{C-j} aka @samp{\n}), unless newline is mentioned as one of the
characters not to match.

@item The character syntax regexps (e.g., @samp{\sw}) are not
meaningful inside character set regexps (e.g., @samp{[aeiou]}).  (This
is actually typical for regexp syntax.)

@end itemize

@node Replacing text across multiple files, Documentation for etags, Using regular expressions, Common requests
@section How do I perform a replace operation across more than one file?
@cindex Replacing strings across files
@cindex Multiple files, replacing across
@cindex Files, replacing strings across multiple

The "tags" feature of Emacs includes the command
@code{tags-query-replace} which performs a query-replace across all the
files mentioned in the TAGS file.  @inforef{Tags Search, Tags Search,
emacs}.

As of Emacs 19.29, Dired mode (@kbd{M-x dired @key{RET}}, or @kbd{C-x
d}) supports the command @code{dired-do-query-replace}, which allows
users to replace regular expressions in multiple files.

@node Documentation for etags, Disabling backups, Replacing text across multiple files, Common requests
@section Where is the documentation for @file{etags}?
@cindex Documentation for @file{etags}
@cindex @file{etags}, documentation for

The @file{etags} man page should be in the same place as the
@file{emacs} man page.

Quick command-line switch descriptions are also available.  For example,
@samp{etags -H}.

@node Disabling backups, Disabling auto-save-mode, Documentation for etags, Common requests
@section How do I disable backup files?
@cindex Backups, disabling
@cindex Disabling backups

You probably don't want to do this, since backups are useful.

To avoid seeing backup files (and other "uninteresting" files) in Dired,
load dired-x by adding the following to your @file{.emacs} file:

@lisp
(add-hook 'dired-load-hook
          (lambda ()
           (load "dired-x")))
@end lisp

With dired-x loaded, @kbd{M-o} toggles omitting in each dired buffer.
You can make omitting the default for new dired buffers by putting the
following in your @file{.emacs}:

@lisp
(setq initial-dired-omit-files-p t)
@end lisp

If you're tired of seeing backup files whenever you do an "ls" at the
Unix shell, try GNU ls with the "-B" option.  GNU ls is part of the GNU
fileutils package, available at mirrors of @samp{ftp.gnu.org} (@pxref{Current GNU distributions} ).

To disable or change how backups are made, see "Backup Names" in the
on-line manual.

@node Disabling auto-save-mode, Modifying pull-down menus, Disabling backups, Common requests
@section How do I disable @code{auto-save-mode}?
@cindex Disabling @code{auto-save-mode}
@cindex Auto-saving
@cindex Saving at frequent intervals

You probably don't want to do this, since auto-saving is useful,
especially when Emacs or your computer crashes while you are editing a
document.

Instead, you might want to change the variable
@code{auto-save-interval}, which specifies how many keystrokes Emacs
waits before auto-saving.  Increasing this value forces Emacs to wait
longer between auto-saves, which might annoy you less.

You might also want to look into Sebastian Kremer's @code{auto-save}
package, available from the Lisp Code Archive (@pxref{Packages that do not come
with Emacs}).  This
package also allows you to place all auto-save files in one directory,
such as @file{/tmp}.

To disable or change how @code{auto-save-mode} works, see "Auto Save" in the
on-line manual.

@node Modifying pull-down menus, Deleting menus and menu options, Disabling auto-save-mode, Common requests
@section How can I create or modify new pull-down menu options?
@cindex Pull-down menus, creating or modifying
@cindex Menus, creating or modifying
@cindex Creating new menu options
@cindex Modifying pull-down menus
@cindex Menus and keymaps
@cindex Keymaps and menus

Each menu title (e.g., Buffers, File, Edit) represents a local or global
keymap.  Selecting a menu title with the mouse displays that keymap's
non-nil contents in the form of a menu.

So to add a menu option to an existing menu, all you have to do is add a
new definition to the appropriate keymap.  Adding a "forward word"
command to the "Edit" menu thus requires the following Lisp code:

@lisp
(define-key global-map           
  [menu-bar edit forward]        
  '("Forward word" . forward-word))
@end lisp

The first line adds the entry to the global keymap, which includes
global menu bar entries.  Replacing the reference to @code{global-map}
with a local keymap would add this menu option only within a particular
mode.

The second line describes the path from the menu-bar to the new entry.
Placing this menu entry underneath the "File" menu would mean changing
the word "edit" in the second line to "file."

The third line is a cons cell whose first element is the title that will
be displayed, and whose second element is the function that will be
called when that menu option is invoked.

To add a new menu, rather than a new option to an existing menu, we must
define an entirely new keymap:

@lisp
(define-key global-map [menu-bar words]
  (cons "Words" (make-sparse-keymap "Words")))
@end lisp

The above code creates a new sparse keymap, gives it the name "Words",
and attaches it to the global menu bar.  Adding the "forward word"
command to this new menu would thus require the following code:

@lisp
(define-key global-map
  [menu-bar words forward]
  '("Forward word" . forward-word))
@end lisp

Note that because of the way keymaps work, menu options are displayed
with the more recently defined items at the top.  Thus if you were to
define menu options "foo", "bar", and "baz" (in that order), menu option
"baz" would appear at the top, and "foo" would be at the bottom.

One way to avoid this problem is to use the function @code{define-key-after},
which works the same as @code{define-key}, but lets you modify where items
appear.  The following Lisp code would insert the "forward word" function
in the "edit" menu immediately following the "undo" option:

@lisp
(define-key-after
  (lookup-key global-map [menu-bar edit])
  [forward]
  '("Forward word" . forward-word)
  'undo)
@end lisp

Note how the second and third arguments to @code{define-key-after} are
different from those of @code{define-key}, and that we have added a new
(final) argument, the function after which our new key should be
defined.

To move a menu option from one position to another, simply evaluate
@code{define-key-after} with the appropriate final argument.

More detailed information --- and more examples of how to create and
modify menu options --- are in the Emacs Lisp Reference Manual, under
"Keymaps".  (@pxref{Emacs Lisp documentation} for information on this
manual.)

@node Deleting menus and menu options, Turning on syntax highlighting, Modifying pull-down menus, Common requests
@section How do I delete menus and menu options?
@cindex Deleting menus and menu options
@cindex Menus, deleting

The simplest way to remove a menu is to set its keymap to @samp{nil}.
For example, to delete the "Words" menu (@pxref{Modifying pull-down
menus}), use:

@lisp
(define-key global-map [menu-bar words] nil)
@end lisp

Similarly, removing a menu option requires redefining a keymap entry to
@code{nil}.  For example, to delete the "Forward word" menu option from the
"Edit" menu (we added it in @ref{Modifying pull-down menus}), use:

@lisp
(define-key global-map [menu-bar edit forward] nil)
@end lisp

@node Turning on syntax highlighting, Scrolling only one line, Deleting menus and menu options, Common requests
@section How do I turn on syntax highlighting?
@cindex Syntax highlighting
@cindex @code{font-lock-mode}
@cindex Highlighting based on syntax
@cindex Colorizing text
@cindex FAQ, @code{font-lock-mode}

@code{font-lock-mode} is the standard way to have Emacs perform syntax
highlighting.  With @code{font-lock-mode} invoked, different types of
text will appear in different colors.  For instance, if you turn on
@code{font-lock-mode} in a programming mode, variables will appear in one
face, keywords in a second, and comments in a third.

Earlier versions of Emacs supported hilit19, a similar package.  Use of
hilit19 is now considered non-standard, although @file{hilit19.el} comes
with the stock Emacs distribution.  It is no longer maintained.

To turn @code{font-lock-mode} on within an existing buffer, use @kbd{M-x
font-lock-mode @key{RET}}.

To automatically invoke @code{font-lock-mode} when a particular major
mode is invoked, set the major mode's hook.  For example, to fontify all
@code{c-mode} buffers, add the following to your @file{.emacs} file:

@lisp
(add-hook 'c-mode-hook 'turn-on-font-lock)
@end lisp

To automatically invoke @code{font-lock-mode} for all major modes, you
can turn on @code{global-font-lock-mode} by including the following line
in your @file{.emacs} file:

@lisp
(global-font-lock-mode 1)
@end lisp

This instructs Emacs to turn on font-lock mode in those buffers for
which a font-lock mode definition has been provided (in the variable
@code{font-lock-global-modes}).  If you edit a file in
@code{pie-ala-mode}, and no font-lock definitions have been provided for
@code{pie-ala} files, then the above setting will have no effect on that
particular buffer.

Highlighting with @code{font-lock-mode} can take quite a while, and thus
different levels of decoration are available, from slight to gaudy.  To
control how decorated your buffers should become, set the value of
@code{font-lock-maximum-decoration} in your @file{.emacs} file, with a
@code{nil} value indicating default (usually minimum) decoration, and a
@code{t} value indicating the maximum decoration.  For the gaudiest
possible look, then, include the line

@lisp
(setq font-lock-maximum-decoration t)
@end lisp

in your @file{.emacs} file.  You can also set this variable such that
different modes are highlighted in a different ways; for more
information, see the documentation for
@code{font-lock-maximum-decoration} with @kbd{C-h v} (or @kbd{M-x
describe-variable @key{RET}}).

You might also want to investigate @code{fast-lock-mode} and
@code{lazy-lock-mode}, versions of @code{font-lock-mode} that speed up
highlighting.  The advantage of @code{lazy-lock-mode} is that it only
fontifies buffers when certain conditions are met, such as after a
certain amount of idle time, or after you have finished scrolling
through text.  See the documentation for @code{lazy-lock-mode} by typing @kbd{C-h f
@code{lazy-lock-mode}} (@kbd{M-x describe-function @key{RET}
lazy-lock-mode @key{RET}}).

Also see the documentation for the function @code{font-lock-mode},
available by typing @kbd{C-h f font-lock-mode} (@kbd{M-x
describe-function @key{RET} font-lock-mode @key{RET}}).

For more information on font-lock mode, take a look at the
@code{font-lock-mode} FAQ, maintained by
@email{jari.aalto@@ntc.nokia.com, Jari Aalto} at

@uref{ftp://cs.uta.fi/pub/ssjaaa/ema-font.gui}

To print buffers with the faces (i.e., colors and fonts) intact, use
@kbd{M-x ps-print-buffer-with-faces} or @kbd{M-x
ps-print-region-with-faces}.

@node Scrolling only one line, Replacing highlighted text, Turning on syntax highlighting, Common requests
@section How can I force Emacs to scroll only one line when I move past the bottom of the screen?
@cindex Scrolling only one line
@cindex Reducing the increment when scrollng

Place the following Lisp form in your @file{.emacs} file:

@lisp
(setq scroll-step 1)
@end lisp

@inforef{Scrolling, Scrolling, emacs}.

@node Replacing highlighted text, Editing MS-DOS files, Scrolling only one line, Common requests
@section How can I replace highlighted text with what I type?
@cindex @code{delete-selection-mode}
@cindex Replacing highlighted text
@cindex Highlighing and replacing text

Use @code{delete-selection mode}, which you can start automatically by
placing the following Lisp form in your @file{.emacs} file:

@lisp
(delete-selection-mode t)
@end lisp

According to the documentation string for delete-selection mode (which
you can read using @kbd{M-x describe-function @key{RET}
delete-selection-mode @key{RET}}):

@quotation
When ON, typed text replaces the selection if the selection is active.
When OFF, typed text is just inserted at point.
@end quotation

This mode also allows you to delete (not kill) the highlighted region by
pressing @key{DEL}.

@node Editing MS-DOS files, Filling paragraphs with a single space, Replacing highlighted text, Common requests
@section How can I edit MS-DOS files using Emacs?
@cindex Editing MS-DOS files
@cindex MS-DOS files, editing
@cindex Microsoft files, editing
@cindex Windows files, editing

As of Emacs 20, detection and handling of MS-DOS (and Windows) files is
performed transparently. You can open MS-DOS files on a Unix system,
edit it, and save it without having to worry about the file format.

When editing an MS-DOS style file, a backslash (@samp{\}) will appear in
the mode line.

If you are running an earlier version of Emacs, get @code{crypt++} from
the Emacs Lisp Archive (@pxref{Packages that do not come with Emacs}).
Among other things, @code{crypt++} transparently modifies MS-DOS files
as they are loaded and saved, allowing you to ignore the different
conventions that Unix and MS-DOS have for delineating the end of a line.

@node Filling paragraphs with a single space,  , Editing MS-DOS files, Common requests
@section How can I tell Emacs to fill paragraphs with a single space after each period?
@cindex One space following periods
@cindex Single space following periods
@cindex Periods, one space following

@email{ulm@@vsnhd1.cern.ch, Ulrich Mueller} suggests adding the
following two lines to your @file{.emacs} file:

@lisp
(setq sentence-end "[.?!][]\"')@}]*\\($\\|[ \t]\\)[ \t\n]*")
(setq sentence-end-double-space nil)
@end lisp

@c ------------------------------------------------------------
@node    Bugs and problems, Compiling and installing Emacs, Common requests, Top
@chapter Bugs and problems
@cindex Bugs and problems

@menu
* Problems with very large files::  
* ^M in the shell buffer::      
* Shell process exits abnormally::  
* Termcap/Terminfo entries for Emacs::  
* Spontaneous entry into isearch-mode::  
* Problems talking to certain hosts::  
* Errors with init files::      
* Emacs ignores X resources::   
* Emacs takes a long time to visit files::  
* Editing files with $ in the name::  
* Shell mode loses the current directory::  
* Security risks with Emacs::   
* Dired claims that no file is on this line::  
@end menu

@node Problems with very large files, ^M in the shell buffer, Bugs and problems, Bugs and problems
@section Does Emacs have problems with files larger than 8 megabytes?
@cindex Very large files, opening
@cindex Large files, opening
@cindex Opening very large files
@cindex Maximum file size
@cindex Files, maximum size

Old versions (i.e., anything before 19.29) of Emacs had problems editing
files larger than 8 megabytes.  As of version 19.29, the maximum buffer
size is at least 2^27-1, or 134,217,727 bytes.

If you are using an older version of Emacs and cannot upgrade, you will
have to recompile. @email{lnz@@lucid.com, Leonard N. Zubkoff} suggests
putting the following two lines in @file{src/config.h} before compiling
Emacs to allow for 26-bit integers and pointers (and thus file sizes of
up to 33,554,431 bytes):

@example
#define VALBITS 26
#define GCTYPEBITS 5
@end example

This method may result in "ILLEGAL DATATYPE" and other random errors on
some machines.

@email{daveg@@csvax.cs.caltech.edu, David Gillespie} explains how this
problems crops up; while his numbers are true only for pre-19.29
versions of Emacs, the theory remains the same with current versions.

@quotation
Emacs is largely written in a dialect of Lisp; Lisp is a freely-typed
language in the sense that you can put any value of any type into any
variable, or return it from a function, and so on.  So each value
must carry a "tag" along with it identifying what kind of thing it is,
e.g., integer, pointer to a list, pointer to an editing buffer, and so
on.  Emacs uses standard 32-bit integers for data objects, taking the
top 8 bits for the tag and the bottom 24 bits for the value.  So
integers (and pointers) are somewhat restricted compared to true C
integers and pointers.
@end quotation

@node ^M in the shell buffer, Shell process exits abnormally, Problems with very large files, Bugs and problems
@section How do I get rid of @samp{^M} or echoed commands in my shell buffer?
@cindex Shell buffer, echoed commands and @samp{^M} in
@cindex Echoed commands in @code{shell-mode}

Try typing @kbd{M-x shell-strip-ctrl-m @key{RET}} while in @code{shell-mode} to
make them go away.  If that doesn't work, you have several options:

For tcsh, put this in your @file{.cshrc} (or @file{.tcshrc}) file:

@example
if ($?EMACS) then
    if ("$EMACS" == t) then
        if ($?tcsh) unset edit
        stty nl
    endif
endif
@end example

Or put this in your @file{.emacs_tcsh} file:

@example
unset edit
stty nl
@end example

Alternatively, use @file{csh} in your shell buffers instead of
@file{tcsh}.  One way is:

@lisp
(setq explicit-shell-file-name "/bin/csh")
@end lisp

and another is to do this in your @file{.cshrc} (or @file{.tcshrc})
file:

@example
setenv ESHELL /bin/csh
@end example

(You must start Emacs over again with the environment variable properly
set for this to take effect.)

You can also set the @code{ESHELL} environment variable in Emacs Lisp
with the following Lisp form,

@lisp
(setenv "ESHELL" "/bin/csh")
@end lisp

On a related note: If your shell is echoing your input line in the shell
buffer, you might want to try the following command in your shell
start-up file:

@example
stty -icrnl -onlcr -echo susp ^Z
@end example

@node Shell process exits abnormally, Termcap/Terminfo entries for Emacs, ^M in the shell buffer, Bugs and problems
@section Why do I get "Process shell exited abnormally with code 1"?
@cindex Abnormal exits from @code{shell-mode}
@cindex @code{shell-mode} exits

The most likely reason for this message is that the @samp{env} program
is not properly installed.  Compile this program for your architecture,
and install it with @samp{a+x} permission in the architecture-dependent
Emacs program directory.  (You can find what this directory is at your
site by inspecting the value of the variable @code{exec-directory} by
typing @kbd{C-h v exec-directory @key{RET}}.)

You should also check for other programs named @samp{env} in your path
(e.g., SunOS has a program named @file{/usr/bin/env}).  We don't
understand why this can cause a failure and don't know a general
solution for working around the problem in this case.

The @samp{make clean} command will remove @samp{env} and other vital
programs, so be careful when using it.

It has been reported that this sometimes happened when Emacs was started
as an X client from an xterm window (i.e., had a controlling tty) but the
xterm was later terminated.

See also @samp{PROBLEMS} (in the top-level directory when you unpack the
Emacs source) for other possible causes of this message.

@node Termcap/Terminfo entries for Emacs, Spontaneous entry into isearch-mode, Shell process exits abnormally, Bugs and problems
@section Where is the termcap/terminfo entry for terminal type "emacs"?
@cindex Termcap
@cindex Terminfo
@cindex Emacs entries for termcap/terminfo

The termcap entry for terminal type @samp{emacs} is ordinarily put in
the @samp{TERMCAP} environment variable of subshells.  It may help in
certain situations (e.g., using rlogin from shell buffer) to add an
entry for @samp{emacs} to the system-wide termcap file.  Here is a
correct termcap entry for @samp{emacs}:

@example
emacs:tc=unknown:
@end example

To make a terminfo entry for "emacs", use "tic" or "captoinfo."  You need
to generate @file{/usr/lib/terminfo/e/emacs}.  It may work to simply copy
@file{/usr/lib/terminfo/d/dumb} to @file{/usr/lib/terminfo/e/emac}s.

Having a termcap/terminfo entry will not enable the use of full screen
programs in shell buffers.  Use @kbd{M-x terminal-emulator} for that
instead.

A workaround to the problem of missing termcap/terminfo entries is to
change terminal type "emacs" to type "dumb" or "unknown" in your shell
start up file.  "csh" users could put this in their .cshrc files:

@example
if ("$term" == emacs) set term=dumb
@end example

@node Spontaneous entry into isearch-mode, Problems talking to certain hosts, Termcap/Terminfo entries for Emacs, Bugs and problems
@section Why does Emacs spontaneously start displaying "I-search:" and beeping?
@cindex Spontaneous entry into isearch-mode
@cindex isearch-mode, spontaneous entry into
@cindex Beeping without obvious reason

Your terminal (or something between your terminal and the computer) is
sending @kbd{C-s} and @kbd{C-q} for flow control, and Emacs is receiving
these characters and interpreting them as commands.  (The @kbd{C-s}
character normally invokes the @code{isearch-forward} command.)  For
possible solutions, @pxref{Handling C-s and C-q with flow control}.

@node Problems talking to certain hosts, Errors with init files, Spontaneous entry into isearch-mode, Bugs and problems
@section Why can't Emacs talk to certain hosts (or certain hostnames)?
@cindex Hosts, Emacs cannot talk to
@cindex @code{gethostbyname}, problematic version

The problem may be that Emacs is linked with a wimpier version of
@code{gethostbyname} than the rest of the programs on the machine.  This
is often manifested as a message on startup of "X server not responding.
Check your @samp{DISPLAY} environment variable." or a message of
"Unknown host" from @code{open-network-stream}.

On a Sun, this may be because Emacs had to be linked with the static C
library.  The version of @code{gethostbyname} in the static C library
may only look in @file{/etc/hosts} and the NIS (YP) maps, while the
version in the dynamic C library may be smart enough to check DNS in
addition to or instead of NIS.  On a Motorola Delta running System V
R3.6, the version of @code{gethostbyname} in the standard library works,
but the one that works with NIS doesn't (the one you get with -linet).
Other operating systems have similar problems.

Try these options:

@itemize @bullet

@item
Explicitly add the host you want to communicate with to @file{/etc/hosts}.

@item
Relink Emacs with this line in @file{src/config.h}:

@example
#define LIBS_SYSTEM -lresolv
@end example

@item
Replace @code{gethostbyname} and friends in @file{libc.a} with more
useful versions such as the ones in @file{libresolv.a}.  Then relink
Emacs.

@item
If you are actually running NIS, make sure that "ypbind" is properly
told to do DNS lookups with the correct command line switch.

@end itemize

@node Errors with init files, Emacs ignores X resources, Problems talking to certain hosts, Bugs and problems
@section Why does Emacs say "Error in init file"?
@cindex Error in @file{.emacs}
@cindex Error in init file
@cindex Init file, errors in
@cindex @file{.emacs} file, errors in
@cindex Debugging @file{.emacs} file

An error occurred while loading either your @file{.emacs} file or the
system-wide file @file{lisp/default.el}.

For information on how to debug your @file{.emacs} file,
@pxref{Debugging a customization file}.

It may be the case that you need to load some package first, or use a
hook that will be evaluated after the package is loaded.  A common case
of this is explained in @ref{Terminal setup code works after Emacs has
begun}.

@node Emacs ignores X resources, Emacs takes a long time to visit files, Errors with init files, Bugs and problems
@section Why does Emacs ignore my X resources (my .Xdefaults file)?
@cindex X resources being ignored
@cindex Ignored X resources
@cindex @file{.Xdefaults}

As of version 19, Emacs searches for X resources in the files specified
by the following environment variables:

@itemize @bullet

@item @code{XFILESEARCHPATH}
@item @code{XUSERFILESEARCHPATH}
@item @code{XAPPLRESDIR} 

@end itemize

This emulates the functionality provided by programs written using Xt.

@code{XFILESEARCHPATH} and @code{XUSERFILESEARCHPATH} should be a list
of file names separated by colons.  @code{XAPPLRESDIR} should be a list
of directory names separated by colons.

Emacs searches for X resources:

@enumerate

@item specified on the command line, with the @samp{-xrm RESOURCESTRING} option,
@item then in the value of the @samp{XENVIRONMENT} environment variable,

@itemize @minus 

@item or if that is unset, in the file named @samp{~/.Xdefaults-HOSTNAME} if it exists (where @samp{HOSTNAME} is the hostname of the machine Emacs is running on),

@end itemize

@item then in the screen-specific and server-wide resource properties provided by the server,

@itemize @minus

@item or if those properties are unset, in the file named ~/.Xdefaults if it exists,

@end itemize

@item then in the files listed in @samp{XUSERFILESEARCHPATH},

@itemize @minus

@item or in files named @file{LANG/Emacs} in directories listed in @samp{XAPPLRESDIR} (where @samp{LANG} is the value of the @samp{LANG} environment variable), if the @samp{LANG} environment variable is set,
@item or in files named Emacs in the directories listed in @samp{XAPPLRESDIR}
@item or in @file{~/LANG/Emacs} (if the @samp{LANG} environment variable is set),
@item  or in @file{~/Emacs},

@end itemize

@item then in the files listed in  @code{XFILESEARCHPATH}.

@end enumerate

@node Emacs takes a long time to visit files, Editing files with $ in the name, Emacs ignores X resources, Bugs and problems
@section Why does Emacs take 20 seconds to visit a file?
@cindex Visiting files takes a long time
@cindex Delay when visiting files
@cindex Files, take a long time to visit

Old versions of Emacs (i.e., versions before Emacs 20.x) often
encountered this when the master lock file, @file{!!!SuperLock!!!} has
been left in the lock directory somehow.  Delete it.

@email{meuer@@geom.umn.edu, Mark Meuer} says that NeXT NFS has a bug
where an exclusive create succeeds but returns an error status.  This
can cause the same problem.  Since Emacs's file locking doesn't work
over NFS anyway, the best solution is to recompile Emacs with
@code{CLASH_DETECTION} undefined.

@node Editing files with $ in the name, Shell mode loses the current directory, Emacs takes a long time to visit files, Bugs and problems
@section How do I edit a file with a @samp{$} in its name?
@cindex Editing files with @samp{$} in the name
@cindex @samp{$} in filenames
@cindex Filenames containing @samp{$}, editing

When entering a filename in the minibuffer, Emacs will attempt to expand
a @samp{$} followed by a word as an environment variable.  To suppress
this behavior, type @kbd{$$} instead.

@node Shell mode loses the current directory, Security risks with Emacs, Editing files with $ in the name, Bugs and problems
@section Why does shell mode lose track of the shell's current directory?
@cindex Current directory and @code{shell-mode}
@cindex @code{shell-mode} and current directory
@cindex Directory, current in @code{shell-mode}

Emacs has no way of knowing when the shell actually changes its
directory.  This is an intrinsic limitation of Unix.  So it tries to
guess by recognizing @samp{cd} commands.  If you type "cd" followed by a
directory name with a variable reference (@samp{cd $HOME/bin}) or with a
shell metacharacter (@samp{cd ../lib*}), Emacs will fail to correctly
guess the shell's new current directory.  A huge variety of fixes and
enhancements to shell mode for this problem have been written to handle
this problem.  Check the Lisp Code Directory (@pxref{Finding a package
with particular functionality}).

You can tell Emacs the shell's current directory with the command
@kbd{M-x dirs}.

@node Security risks with Emacs, Dired claims that no file is on this line, Shell mode loses the current directory, Bugs and problems
@section Are there any security risks in Emacs?
@cindex Security with Emacs
@cindex @samp{movemail} and security
@cindex @code{file-local-variable} and security
@cindex Synthetic X events and security
@cindex X events and security

@itemize @bullet

@item The @file{movemail} incident (No, this is not a risk.)

In his book @emph{The Cuckoo's Egg}, Cliff Stoll describes this in
chapter 4.  The site at LBL had installed the @file{etc/movemail}
program setuid root.  (As of version 19, @file{movemail} is in your
architecture-specific directory; type @kbd{C-h v exec-directory
@key{RET}} to see what it is.)  Since @file{movemail} had not been
designed for this situation, a security hole was created and users could
get root privileges.

@file{movemail} has since been changed so that this security hole will
not exist, even if it is installed setuid root.  However,
@file{movemail} no longer needs to be installed setuid root, which
should eliminate this particular risk.

We have heard unverified reports that the 1988 Internet worm took
advantage of this configuration problem.

@item The @code{file-local-variable} feature (Yes, a risk, but easy to change.)

There is an Emacs feature that allows the setting of local values for
variables when editing a file by including specially formatted text near
the end of the file.  This feature also includes the ability to have
arbitrary Emacs Lisp code evaluated when the file is visited.
Obviously, there is a potential for Trojan horses to exploit this
feature.

Emacs 18 allowed this feature by default; users could disable it by
setting the variable @code{inhibit-local-variables} to a non-nil value.

As of Emacs 19, Emacs has a list of local variables that create a
security risk.  If a file tries to set one of them, it asks the user to
confirm whether the variables should be set.  You can also tell Emacs
whether to allow the evaluation of Emacs Lisp code found at the bottom
of files by setting the variable @code{enable-local-eval}.

For more information, @inforef{File Variables, File Variables, emacs}.

@item Synthetic X events (Yes, a risk; use @samp{MIT-MAGIC-COOKIE-1} or better.)

Emacs accepts synthetic X events generated by the SendEvent request as
though they were regular events.  As a result, if you are using the
trivial host-based authentication, other users who can open X
connections to your X workstation can make your Emacs process do
anything, including run other processes with your privileges.

The only fix for this is to prevent other users from being able to open
X connections.  The standard way to prevent this is to use a real
authentication mechanism, such as @samp{MIT-MAGIC-COOKIE-1}.  If using
the @file{xauth} program has any effect, then you are probably using
@samp{MIT-MAGIC-COOKIE-1}.  Your site may be using a superior
authentication method; ask your system administrator.

If real authentication is not a possibility, you may be satisfied by
just allowing hosts access for brief intervals while you start your X
programs, then removing the access.  This reduces the risk somewhat by
narrowing the time window when hostile users would have access, but
@emph{does not eliminate the risk}.

On most computers running Unix and X Windows, you enable and disable
access using the @file{xhost} command.  To allow all hosts access to
your X server, use

@example
xhost +
@end example

at the shell prompt, which (on an HP machine, at least) produces the
following message:

@example
access control disabled, clients can connect from any host
@end example

To deny all hosts access to your X server (except those explicitly
allowed by name), use

@example
xhost -
@end example

On the test HP computer, this command generated the following message:

@example
access control enabled, only authorized clients can connect
@end example

@end itemize

@node Dired claims that no file is on this line,  , Security risks with Emacs, Bugs and problems
@section Dired says, "no file on this line" when I try to do something.
@cindex Dired does not see a file

Chances are you're using a localized version of Unix that doesn't use US
date format in dired listings.  You can check this by looking at dired
listings or by typing @code{ls -l} to a shell and looking at the dates that
come out.

Dired uses a regular expression to find the beginning of a file name.
In a long Unix-style directory listing ("ls -l"), the file name starts
after the date.  The regexp has thus been written to look for the date,
the format of which can vary on non-US systems.

There are two approaches to solving this.  The first one involves
setting things up so that "ls -l" outputs US date format.  This can be
done by setting the locale.  See your OS manual for more information.

The second approach involves changing the regular expression used by
dired, @code{dired-move-to-filename-regexp}.

@c ------------------------------------------------------------
@node Compiling and installing Emacs, Finding Emacs and related packages, Bugs and problems, Top
@chapter    Compiling and installing Emacs
@cindex    Compiling and installing Emacs

@menu
* Installing Emacs::            
* Updating Emacs::              
* Problems building Emacs::     
* Linking with -lX11 fails::    
@end menu

@node Installing Emacs, Updating Emacs, Compiling and installing Emacs, Compiling and installing Emacs
@section How do I install Emacs?
@cindex Installing Emacs
@cindex Unix systems, installing Emacs on
@cindex Downloading and installing Emacs
@cindex Retrieving and installing Emacs
@cindex Building Emacs from source
@cindex Source code, building Emacs from
@cindex Unpacking and installing Emacs

This answer is meant for users of Unix and Unix-like systems.  Users of
other operating systems should see the series of questions beginning
with @ref{Emacs for MS-DOS}, which describe where to get non-Unix source
and binaries.  These packages should come with installation
instructions.

For Unix and Unix-like systems, the easiest way is often to compile it
from scratch.  You will need:

@itemize @bullet

@item
Emacs sources.  @xref{Current GNU distributions}, for a list of ftp sites
that make them available.  On @file{ftp.gnu.org}, the main GNU
distribution site, sources are available at

@uref{ftp://ftp.gnu.org/pub/gnu/emacs/emacs-20.5.tar.gz}

The above will obviously change as new versions of Emacs come out.  For
instance, when Emacs 21 is released, it will most probably be
available at

@uref{ftp://ftp.gnu.org/pub/gnu/emacs/emacs-21.1.tar.gz}

Again, you should use one of the GNU mirror sites (@xref{Current GNU
distributions}, and adjust the URL accordingly) so as to reduce load on
@file{ftp.gnu.org}.

@item
@code{gzip}, the GNU compression utility.  You can get @code{gzip} via
anonymous ftp at mirrors of @file{ftp.gnu.org} sites; it should compile
and install without much trouble on most systems.  Once you have
retrieved the Emacs sources, you will probably be able to uncompress
them with the command

@example
gunzip --verbose emacs-20.5.tar.gz
@end example

changing the Emacs version (20.5), as necessary.  Once gunzip has
finished doing its job, a file by the name of "emacs-20.5.tar" should
be in your build directory.

@item 
@file{tar}, the "tape archiving" program, which moves multiple files
into and out of archive files, or "tarfiles."  All of the files
comprising the Emacs source come in a single tarfile, and must be
extracted using @file{tar} before you can build Emacs.  Typically, the
extraction command would look like

@example
tar -xvvf emacs-20.5.tar
@end example

The @samp{x} indicates that we want to extract files from this tarfile,
the two @samp{v}s force verbose output, and the @samp{f} tells
@file{tar} to use a disk file, rather than one on tape.

If you're using GNU @file{tar} (available at mirrors of
@file{ftp.gnu.org}), you can combine this step and the previous one by
using the command

@example
tar -zxvvf emacs-20.5.tar.gz
@end example

The additional @samp{z} at the beginning of the options list tells GNU tar
to uncompress the file with gunzip before extracting the tarfile's
components.

@end itemize

At this point, the Emacs sources (all 25+ megabytes of them) should be
sitting in a directory called @file{emacs-20.5}.  On most common Unix and
Unix-like systems, you should be able to compile Emacs (with X Windows
support) with the following commands:

@example
cd emacs-20.5       # change directory to emacs-20.5
./configure         # configure Emacs for your particular system 
make                # use Makefile to build components, then Emacs 
@end example

If the @code{make} completes successfully, the odds are fairly good that
the build has gone well.  (@pxref{Problems building Emacs} if you weren't
successful.)

By default, Emacs is installed in the following directories:

@table @file

@item /usr/local/bin
binaries

@item /usr/local/share/emacs/20.xx
Lisp code and support files

@item /usr/local/info
Info documentation

@end table

To install files in those default directories, become the superuser and
type

@example
make install
@end example

Note that @code{make install} will overwrite @file{/usr/local/bin/emacs}
and any Emacs Info files that might be in @file{/usr/local/info}.

Much more verbose instructions (with many more hints and suggestions)
come with the Emacs sources, in the file @file{INSTALL}.

@node Updating Emacs, Problems building Emacs, Installing Emacs, Compiling and installing Emacs
@section How do I update Emacs to the latest version?
@cindex Updating Emacs

@xref{Installing Emacs}, and follow the instructions there for
installation.

Most files are placed in version-specific directories.  Emacs 20.5, for
instance, places files in @file{/usr/local/share/emacs/20.5}.

Upgrading should overwrite only, @file{/usr/local/bin/emacs} (the Emacs
binary) and documentation in @file{/usr/local/info}.  Back up these
files before you upgrade, and you shouldn't have too much trouble.

@node Problems building Emacs, Linking with -lX11 fails, Updating Emacs, Compiling and installing Emacs
@section What should I do if I have trouble building Emacs?
@cindex Problems building Emacs
@cindex Errors when building Emacs

First look in the file @file{PROBLEMS} (in the top-level directory when
you unpack the Emacs source) to see if there is already a solution for
your problem.  Next, look for other questions in this FAQ that have to
do with Emacs installation and compilation problems.

If you'd like to have someone look at your problem and help solve it,
@pxref{Help installing Emacs}.

If you cannot find a solution in the documentation, send a message to
@email{bug-gnu-emacs@@gnu.org}.

Please do not post it to @uref{news:gnu.emacs.help} or send e-mail to
@email{help-gnu-emacs@@gnu.org}.  For further guidelines,
@pxref{Guidelines for newsgroup postings} and @ref{Reporting bugs}.

@node Linking with -lX11 fails,  , Problems building Emacs, Compiling and installing Emacs
@section Why does linking Emacs with -lX11 fail?
@cindex Linking with -lX11 fails
@cindex lX11, linking fails with

Emacs needs to be linked with the static version of the X11 library,
@file{libX11.a}.  This may be missing.

Under OpenWindows, you may need to use "add_services" to add the
"OpenWindows Programmers" optional software category from the CD-ROM.

Under HP-UX 8.0, you may need to run "update" again to load the X11-PRG
"fileset".  This may be missing even if you specified "all filesets" the
first time.  If @file{libcurses.a} is missing, you may need to load the
"Berkeley Development Option."

@email{zoo@@armadillo.com, David Zuhn} says that MIT X builds shared
libraries by default, and only shared libraries, on those platforms that
support them.  These shared libraries can't be used when undumping
temacs (the last stage of the Emacs build process).  To get regular
libraries in addition to shared libraries, add this to @file{site.cf}:

@example
#define ForceNormalLib YES
@end example

Other systems may have similar problems.  You can always define
CANNOT_DUMP and link with the shared libraries instead.

To get the Xmenu stuff to work, you need to find a copy of MIT's
@file{liboldX.a}.

@c ------------------------------------------------------------
@node Finding Emacs and related packages, Major packages and programs, Compiling and installing Emacs, Top
@chapter Finding Emacs and related packages
@cindex Finding Emacs and related packages

@menu
* Finding Emacs on the Internet::  
* Finding a package with particular functionality::  
* Packages that do not come with Emacs::  
* Submitting to the Emacs Lisp Archive::  
* Current GNU distributions::   
* Difference between Emacs and XEmacs::  
* Emacs for MS-DOS::            
* Emacs for Windows::           
* Emacs for OS/2::              
* Emacs for Atari ST::          
* Emacs for the Amiga ::        
* Emacs for NeXTSTEP::          
* Emacs for Apple computers::   
* Emacs for VMS and DECwindows::  
* Modes for various languages::  
* Translating names to IP addresses::  
@end menu

@node Finding Emacs on the Internet, Finding a package with particular functionality, Finding Emacs and related packages, Finding Emacs and related packages
@section Where can I get Emacs on the net (or by snail mail)?
@cindex Finding Emacs on the Internet
@cindex Snail mail, ordering Emacs via
@cindex Postal service, ordering Emacs via
@cindex Distribution, retrieving Emacs 
@cindex Internet, retreiving from

Look in the files @file{etc/DISTRIB} and @file{etc/FTP} for information
on nearby archive sites and @file{etc/ORDERS} for mail orders.  If you
don't already have Emacs, @pxref{Informational files for Emacs} for how
to get these files.

@xref{Installing Emacs}, for information on how to obtain and build the latest
version of Emacs, and @pxref{Current GNU distributions} for a list of
archive sites that make GNU software available.

@node Finding a package with particular functionality, Packages that do not come with Emacs, Finding Emacs on the Internet, Finding Emacs and related packages
@section How do I find a Emacs Lisp package that does XXX?
@cindex Package, finding
@cindex Finding an Emacs Lisp package
@cindex Functionality, finding a particular package 

First of all, you should check to make sure that the package isn't
already available.  For example, typing @kbd{M-x apropos @key{RET}
wordstar @key{RET}} lists all functions and variables containing the
string @samp{wordstar}.

It is also possible that the package is on your system, but has not been
loaded.  To see which packages are available for loading, look through
your computer's lisp directory (@pxref{Filename conventions}).  The Lisp
source to most most packages contains a short description of how they
should be loaded, invoked, and configured --- so before you use or
modify a Lisp package, see if the author has provided any hints in the
source code.

If a package does not come with Emacs, check the Lisp Code Directory.
The LCD was originally maintained by @email{brennan@@hal.com, Dave
Brennan}, but was recently taken over by @email{toby@@world.std.com,
toby knudsen}, who maintains @uref{http://www.emacs.org}.  The LCD is
currently being reorganized and updated, but you can meanwhile find many
packages at @uref{ftp://ftp.emacs.org/pub}.

For now, you can search through the LCD with @file{lispdir.el}, which is
in the process of being updated.  Download it from the LCD, in the
@file{emacs-lisp-attic/misc} directory, and then evaluate the following
Lisp form (@pxref{Evaluating Emacs Lisp code}):

@lisp
(setq lisp-code-directory
 "/anonymous@@ftp.emacs.org:pub/emacs-lisp-attic/emacs-lisp/LCD-datafile.gz"
  elisp-archive-host "ftp.emacs.org"
  elisp-archive-directory "/pub/emacs-lisp-attic/emacs-lisp/")
@end lisp

Once you have installed @file{lispdir.el}, you can use @kbd{M-x
lisp-dir-apropos} to search the listing.  For example, @kbd{M-x
lisp-dir-apropos @key{RET} ange-ftp @key{RET}} produces this output:

@example
         GNU Emacs Lisp Code Directory Apropos --- "ange-ftp"
"~/" refers to archive.cis.ohio-state.edu:pub/elisp-archive/

     ange-ftp (4.18)       15-Jul-1992
          Andy Norman, <ange@@hplb.hpl.hp.com>
          ~/packages/ange-ftp.tar.Z
          transparent FTP Support for GNU Emacs
     auto-save (1.19)      01-May-1992
          Sebastian Kremer, <sk@@thp.uni-koeln.de>
          ~/misc/auto-save.el.Z
          Safer autosaving with support for ange-ftp and /tmp
     ftp-quik (1.0)        28-Jul-1993
          Terrence Brannon, <tb06@@pl122f.eecs.lehigh.edu>
          ~/modes/ftp-quik.el.Z
          Quik access to dired'ing of ange-ftp and normal paths
@end example

@node Packages that do not come with Emacs, Submitting to the Emacs Lisp Archive, Finding a package with particular functionality, Finding Emacs and related packages
@section Where can I get Emacs Lisp packages that don't come with Emacs?
@cindex Unbundled packages
@cindex Finding other packages
@cindex Lisp packages that do not come with Emacs
@cindex Packages, those that do not come with Emacs
@cindex Emacs Lisp Archive, description of
@cindex Archive, description of the Emacs Lisp

First, check the Lisp Code Directory to find the name of the package you
are looking for (@pxref{Finding a package with particular
functionality}).  Next, check local archives and the Emacs Lisp Archive
to find a copy of the relevant files.  If you still haven't found it,
you can send e-mail to the author asking for a copy.  If you find Emacs
Lisp code that doesn't appear in the LCD, please submit a copy to the
LCD (@pxref{Submitting to the Emacs Lisp Archive}).

You can access the Emacs Lisp Archive at

@uref{ftp://archive.cis.ohio-state.edu/pub/emacs-lisp/}

Retrieve and read the file @file{README} first.

@itemize @bullet

@item The archive maintainers do not have time to answer individual
requests for packages or the list of packages in the archive.  If you
cannot use FTP or UUCP to access the archive yourself, try to find a
friend who can, but please don't ask the maintainers.

@item Any files with names ending in @samp{.Z}, @samp{.z}, or @samp{.gz} are
compressed, so you should use "binary" mode in FTP to retrieve them.
You should also use binary mode whenever you retrieve any files with
names ending in @samp{.elc}.

@end itemize

@node Submitting to the Emacs Lisp Archive, Current GNU distributions, Packages that do not come with Emacs, Finding Emacs and related packages
@section How do I submit code to the Emacs Lisp Archive?
@cindex Submitting code to the Emacs Lisp Archive
@cindex Emacs Lisp Archive, submissions to
@cindex Lisp Archive, submissions to
@cindex Archive, submitting to the Emacs Lisp

Guidelines and procedures for submission to the archive can be found in
the file @file{GUIDELINES} in the archive directory (@ref{Packages that
do not come with Emacs}).  It covers documentation, copyrights,
packaging, submission, and the Lisp Code Directory Record.  Anonymous
FTP uploads are not permitted.  Instead, all submissions are mailed to
@email{elisp-archive@@cis.ohio-state.edu}.  The @file{lispdir.el}
package has a function named @code{submit-lcd-entry} which will help you
with this.

@node Current GNU distributions, Difference between Emacs and XEmacs, Submitting to the Emacs Lisp Archive, Finding Emacs and related packages
@section Where can I get other up-to-date GNU stuff?
@cindex Current GNU distributions
@cindex Sources for current GNU distributions
@cindex Stuff, current GNU
@cindex Up-to-date GNU stuff
@cindex Finding current GNU software
@cindex Official GNU software sites

The most up-to-date official GNU software is normally kept at

@uref{ftp://ftp.gnu.org/pub/gnu}

Read the files @file{etc/DISTRIB} and @file{etc/FTP} for more
information.

A list of sites mirroring @samp{ftp.gnu.org} can be found at

@uref{http://www.gnu.org/order/ftp.html}

@node Difference between Emacs and XEmacs, Emacs for MS-DOS, Current GNU distributions, Finding Emacs and related packages
@section What is the difference between Emacs and XEmacs (formerly "Lucid Emacs")?
@cindex XEmacs
@cindex Difference Emacs and XEmacs
@cindex Lucid Emacs
@cindex Epoch

First of all, they're both GNU Emacs.  XEmacs is just as much a later
version of GNU Emacs as the FSF-distributed version.  This FAQ refers to
the latest version to be distributed by the FSF as "Emacs," partly
because the XEmacs maintainers now refer to their product using the
"XEmacs" name, and partly because there isn't any accurate way to
differentiate between the two without getting mired in paragraphs of
legalese and history.

XEmacs, which began life as Lucid Emacs, is based on an early version of
Emacs 19 and Epoch, an X-aware version of Emacs 18.

Emacs (i.e., the version distributed by the FSF) has a larger installed
base and now always contains the MULE multilingual facilities.
XEmacs can do some clever tricks with X Windows, such as
putting arbitrary graphics in a buffer.  Similar facilities have been
implemented for Emacs as part of a new redisplay implementation for
Emacs 21, expected to be released after Emacs 20.5.
Emacs and XEmacs each come with
Lisp packages that are lacking in the other; RMS says that the FSF would
include more packages that come with XEmacs, but that the XEmacs
maintainers don't always keep track of the authors of contributed code,
which makes it impossible for the FSF to have certain legal papers
signed.  (Without these legal papers, the FSF will not distribute Lisp
packages with Emacs.)  The two versions have some
significant differences at the Lisp programming level.

Many XEmacs features have found their way into recent versions of Emacs,
and more features can be expected in the future, but there are still many
differences between the two.

@node Emacs for MS-DOS, Emacs for Windows, Difference between Emacs and XEmacs, Finding Emacs and related packages
@section Where can I get Emacs for my PC running MS-DOS?
@cindex MS-DOS, Emacs for
@cindex DOS, Emacs for
@cindex Compiling Emacs for DOS
@cindex Emacs for MS-DOS
@cindex Tools needed to compile Emacs under DOS

A pre-built binary distribution of Emacs is available from the Simtel
archives.  This version apparently works under MS-DOS and Windows (3.x,
95x, and NT) and supports long file names under Windows 9x.  More
information is available from

@uref{ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/emacs.README}

The binary itself is available in the files em1934*.zip in the
directory

@uref{ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu/}

If you prefer to compile Emacs for yourself, you can do so with the
current distribution directly.  You will need a 386 (or
better) processor, and to be running MS-DOS 3.0 or later.  According to
@email{eliz@@is.elta.co.il, Eli Zaretskii} and
@email{hankedr@@dms.auburn.edu, Darrel Hankerson}, you will need the
following:

@table @emph

@item Compiler
djgpp version 1.12 maint 1 or later.  Djgpp 2.0 or later is
recommended, since 1.x is being phased out.  Djgpp 2 supports
long filenames under Windows 9x.

You can get the latest release of djgpp by retrieving all of
the files in

@uref{ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp}

@item Gunzip and tar
The easiest way is to use "djtar" which comes with djgpp v2.x,
because it can open gzip'ed tarfiles (i.e., those ending with
".tar.gz") in one step.  Djtar comes in "djdev201.zip", from
the URL mentioned above.

@item make, mv, sed, and rm
All of these utilities are available at

@uref{ftp://ftp.simtel.net/pub/simtelnet/gnu/djgpp/v2gnu}

16-bit utilities can be found in GNUish, at

@uref{ftp://ftp.simtel.net/pub/simtelnet/gnu/gnuish}

@end table

The files @file{INSTALL} and @file{PROBLEMS} in the top-level directory
of the Emacs source contains some additional information regarding Emacs
under MS-DOS.

For a list of other MS-DOS implementations of Emacs (and Emacs
look-alikes), consult the list of "Emacs implementations and literature,"
available at

@uref{ftp://rtfm.mit.edu/pub/usenet/comp.emacs/}

Note that while many of these programs look similar to Emacs, they often
lack certain features, such as the Emacs Lisp extension language.

@node Emacs for Windows, Emacs for OS/2, Emacs for MS-DOS, Finding Emacs and related packages
@section Where can I get Emacs for Microsoft Windows
@cindex FAQ for NT Emacs
@cindex Microsoft Windows, Emacs for
@cindex Windows NT, Emacs for
@cindex Windows '95 and '98, Emacs for

For information on Emacs for Windows 95 and NT, read the FAQ produced by
@email{voelker@@cs.washington.edu, Geoff Voelker}, available at

@uref{http://www.gnu.org/software/emacs/windows/ntemacs.html}

@xref{Emacs for MS-DOS}, for Windows 3.1.

@node Emacs for OS/2, Emacs for Atari ST, Emacs for Windows, Finding Emacs and related packages
@section Where can I get Emacs for my PC running OS/2?
@cindex OS/2, Emacs for

Emacs 19.33 is ported for emx on OS/2 2.0 or 2.1, and is available at

@uref{ftp://hobbes.nmsu.edu/pub/os2/apps/editors/emacs/v19.33/}

@node Emacs for Atari ST, Emacs for the Amiga , Emacs for OS/2, Finding Emacs and related packages
@section Where can I get Emacs for my Atari ST?
@cindex Atari ST, Emacs for
@cindex TOS, Emacs for