This is the GNU Emacs FAQ, last updated on 4 June 2007. This FAQ is maintained as a part of GNU Emacs. If you find any errors, or have any suggestions, please use `M-x report-emacs-bug' to report them. 1 FAQ notation ************** This chapter 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. 1.1 What do these mean: `C-h', `C-M-a', , ` a', etc.? =============================================================== * `C-x': press the key while holding down the key * `M-x': press the key while holding down the key (if your computer doesn't have a key, *note No Meta key::) * `M-C-x': press the key while holding down both and * `C-M-x': a synonym for the above * : Linefeed or Newline; same as `C-j' * : , sometimes marked ; same as `C-m' * : , usually *not* the same as ; same as `C-?' (see *Note Backspace invokes help::, if deleting invokes Emacs help) * : Escape; same as `C-[' * : Tab; same as `C-i' * : Space bar Key sequences longer than one key (and some single-key sequences) are written inside quotes or on lines by themselves, like this: `M-x frobnicate-while-foo RET' Any real spaces in such a key sequence should be ignored; only really means press the space key. The ASCII code sent by `C-x' (except for `C-?') is the value that would be sent by pressing just minus 96 (or 64 for upper-case ) and will be from 0 to 31. On Unix and GNU/Linux terminals, the ASCII code sent by `M-x' is the sum of 128 and the ASCII code that would be sent by pressing just . Essentially, turns off bits 5 and 6 and turns on bit 7(1). `C-?' (aka ) is ASCII code 127. It is a misnomer to call `C-?' a "control" key, since 127 has both bits 5 and 6 turned ON. Also, on very few keyboards does `C-?' generate ASCII code 127. *note Text Characters: (emacs)Text Characters, and *note Keys: (emacs)Keys, for more information. (*Note On-line manual::, for more information about Info.) ---------- Footnotes ---------- (1) DOS and Windows terminals don't set bit 7 when the key is pressed. 1.2 What does `M-x COMMAND' mean? ================================= `M-x COMMAND' means type `M-x', then type the name of the command, then type . (*Note Basic keys::, if you're not sure what `M-x' and mean.) `M-x' (by default) invokes the command `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 and for completion, for a list of possibilities, and `M-p' and `M-n' (or up-arrow and down-arrow on terminals that have these editing keys) to see previous commands entered. An Emacs "command" is an "interactive" Emacs function. Your system administrator may have bound other key sequences to invoke `execute-extended-command'. A function key labeled `Do' is a good candidate for this, on keyboards that have such a key. If you need to run non-interactive Emacs functions, see *Note Evaluating Emacs Lisp code::. 1.3 How do I read topic XXX in the on-line manual? ================================================== When we refer you to some TOPIC in the on-line manual, you can read this manual node inside Emacs (assuming nothing is broken) by typing `C-h i m emacs m TOPIC '. This invokes Info, the GNU hypertext documentation browser. If you don't already know how to use Info, type from within Info. If we refer to TOPIC:SUBTOPIC, type `C-h i m emacs m TOPIC m SUBTOPIC '. If these commands don't work as expected, your system administrator may not have installed the Info files, or may have installed them improperly. In this case you should complain. *Note Getting a printed manual::, if you would like a paper copy of the Emacs manual. 1.4 What are `etc/SERVICE', `src/config.h', and `lisp/default.el'? ================================================================== These are files that come with Emacs. The Emacs distribution is divided into subdirectories; the important ones are `etc', `lisp', and `src'. If you use Emacs, but don't know where it is kept on your system, start Emacs, then type `C-h v data-directory '. The directory name displayed by this will be the full pathname of the installed `etc' directory. (This full path is recorded in the Emacs variable `data-directory', and `C-h v' displays the value and the documentation of a variable.) The location of your Info directory (i.e., where on-line documentation is stored) is kept in the variable `Info-default-directory-list'. Use `C-h v Info-default-directory-list ' to see the value 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 `/usr/local/info'. Some of these files are available individually via FTP or e-mail; see *Note Informational files for Emacs::. They all are available in the source distribution. Many of the files in the `etc' directory are also available via the Emacs `Help' menu, or by typing `C-h ?' (`M-x help-for-help'). Your system administrator may have removed the `src' directory and many files from the `etc' directory. 1.5 What are FSF, LPF, OSF, GNU, RMS, FTP, and GPL? =================================================== FSF Free Software Foundation LPF League for Programming Freedom OSF Open Software Foundation GNU GNU's Not Unix RMS Richard Matthew Stallman FTP File Transfer Protocol GPL GNU General Public License 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 cost." 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, since everyone has the right to resell or give away GPL-covered software. 2 General questions ******************* This chapter contains general questions having to do with Emacs, the Free Software Foundation, and related organizations. 2.1 What is the LPF? ==================== 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 Joe Wells ; he will be happy to talk to you about the LPF. You can find more information about the LPF in the file `etc/LPF'. More papers describing the LPF's views are available on the Internet and also from the LPF home page (http://lpf.ai.mit.edu/). 2.2 What is the real legal meaning of the GNU copyleft? ======================================================= 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 `news:gnu.misc.discuss', which was created to hold the extensive flame wars on the subject. RMS writes: 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. 2.3 What are appropriate messages for `news:gnu.emacs.help', `news:gnu.emacs.bug', `news:comp.emacs', etc.? =========================================================================================================== The file `etc/MAILINGLISTS' describes the purpose of each GNU mailing list. (*Note 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. The newsgroup `news:comp.emacs' is for discussion of Emacs programs in general. This includes Emacs along with various other implementations, such as XEmacs, JOVE, MicroEmacs, Freemacs, MG, Unipress, CCA, and Epsilon. Many people post Emacs questions to `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 `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 `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. `news:gnu.emacs.bug' is a place where bug reports appear, but avoid posting bug reports to this newsgroup directly (*note Reporting bugs::). 2.4 Where can I get old postings to `news:gnu.emacs.help' and other 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 `ftp://lists.gnu.org/'. The archive can be browsed over the web at the GNU mail archive (http://lists.gnu.org/archive/html/). Web-based Usenet search services, such as Google (http://groups.google.com/groups/dir?sel=33592484), also archive the `gnu.*' groups. You can read the archives of the `gnu.*' groups and post new messages at Gmane (http://gmane.org/). 2.5 Where should I report bugs and other problems with Emacs? ============================================================= The correct way to report Emacs bugs is to use the command `M-x report-emacs-bug'. It sets up a mail buffer with the essential information and the correct e-mail address which is for the released versions of Emacs. Anything sent to also appears in the newsgroup `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! The manual describes in detail how to submit a useful bug report (*note Reporting Bugs: (emacs)Bugs.). (*Note On-line manual::, if you don't know how to read the manual.) RMS says: Sending bug reports to (which has the effect of posting on `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. 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. RMS says it is sometimes fine to post to `news:gnu.emacs.help': 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. If you are unsure whether you have found a bug, consider the following non-exhaustive list, courtesy of RMS: 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. 2.6 How do I unsubscribe from this mailing list? ================================================ If you are receiving a GNU mailing list named LIST, you might be able to unsubscribe from it by sending a request to the address . 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 `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, if you cannot figure out these details. 2.7 What is the current address of the FSF? =========================================== E-mail gnu@gnu.org Telephone +1-617-542-5942 Fax +1-617-542-2652 World Wide Web `http://www.gnu.org/' Postal address Free Software Foundation 51 Franklin Street, Fifth Floor Boston, MA 02110-1301 USA For details on how to order items directly from the FSF, see the GNU Web site (http://www.gnu.org/order/order.html). 3 Getting help ************** This chapter tells you how to get help with Emacs 3.1 I'm just starting Emacs; how do I do basic editing? ======================================================= Type `C-h t' to invoke the self-paced tutorial. Just typing `C-h' enters the help system. Starting with Emacs 22, the tutorial is available in many foreign languages such as French, German, Japanese, Russian, etc. Use `M-x help-with-tutorial-spec-language ' to choose your language and start the tutorial. Your system administrator may have changed `C-h' to act like to deal with local keyboards. You can use `M-x help-for-help' instead to invoke help. To discover what key (if any) invokes help on your system, type `M-x where-is help-for-help '. 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 `help-char'. 3.2 How do I find out how to do something in Emacs? =================================================== There are several methods for finding out how to do things in Emacs. * The complete text of the Emacs manual is available on-line via the Info hypertext reader. Type `C-h r' to display the manual in Info mode. Typing immediately after entering Info will provide a short tutorial on how to use it. * To quickly locate the section of the manual which discusses a certain issue, or describes a command or a variable, type `C-h i m emacs i TOPIC ', where TOPIC is the name of the topic, the command, or the variable which you are looking for. If this does not land you on the right place in the manual, press `,' (comma) repeatedly until you find what you need. (The `i' and `,' keys invoke the index-searching functions, which look for the TOPIC you type in all the indices of the Emacs manual.) * You can list all of the commands whose names contain a certain word (actually which match a regular expression) using `C-h a' (`M-x command-apropos'). * The command `C-h F' (`Info-goto-emacs-command-node') prompts for the name of a command, and then attempts to find the section in the Emacs manual where that command is described. * You can list all of the functions and variables whose names contain a certain word using `M-x apropos'. * You can list all of the functions and variables whose documentation matches a regular expression or a string, using `M-x apropos-documentation'. * You can order a hardcopy of the manual from the FSF. *Note Getting a printed manual::. * 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 `etc/refcard.tex' or `etc/refcard.ps' files in the Emacs distribution. Beginning with version 21.1, the Emacs distribution comes with translations of the reference card into several languages; look for files named `etc/LANG-refcard.*', where LANG is a two-letter code of the language. For example, the German version of the reference card is in the files `etc/de-refcard.tex' and `etc/de-refcard.ps'. * There are many other commands in Emacs for getting help and information. To get a list of these commands, type `?' after `C-h'. 3.3 How do I get a printed copy of the Emacs manual? ==================================================== You can order a printed copy of the Emacs manual from the FSF. For details see the GNU Web site (http://www.gnu.org/order/order.html). The full Texinfo source for the manual also comes in the `man' directory of the Emacs distribution, if you're daring enough to try to print out this 620-page manual yourself (*note 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 `http://www.gnu.org/software/emacs/manual/emacs.ps.gz' An HTML version of the manual is at `http://www.gnu.org/software/emacs/manual/emacs.html' The manual is available in other formats at `http://www.gnu.org/software/emacs/manual/' *Note Learning how to do something::, for how to view the manual on-line. 3.4 Where can I get documentation on Emacs Lisp? ================================================ Within Emacs, you can type `C-h f' to get the documentation for a function, `C-h v' for a variable. For more information, the Emacs Lisp Reference Manual is available on-line, in Info format. *Note Emacs Lisp: (elisp)Top. You can also order a hardcopy of the manual, details on ordering it from FSF are on the GNU Web site (http://www.gnu.org/order/order.html). An HTML version of the Emacs Lisp Reference Manual is available at `http://www.gnu.org/software/emacs/elisp-manual/elisp.html' 3.5 How do I install a piece of Texinfo documentation? ====================================================== First, you must turn the Texinfo files into Info files. You may do this using the stand-alone `makeinfo' program, available as part of the latest Texinfo package at `ftp://ftp.gnu.org/pub/gnu/texinfo/texinfo-4.8.tar.gz' and all mirrors of `ftp.gnu.org' (for a list, *note Current GNU distributions::). For information about the Texinfo format, read the Texinfo manual which comes with the Texinfo package. This manual also comes installed in Info format, so you can read it on-line; type `C-h i m texinfo '. Alternatively, you could use the Emacs command `M-x texinfo-format-buffer', after visiting the Texinfo source file of the manual you want to convert. Neither `texinfo-format-buffer' nor `makeinfo' installs the resulting Info files in Emacs's Info tree. To install Info files, perform these steps: 1. Move the files to the `info' directory in the installed Emacs distribution. *Note File-name conventions::, if you don't know where that is. 2. Run the `install-info' command, which is part of the Texinfo distribution, to update the main Info directory menu, like this: install-info --info-dir=DIR-PATH DIR-PATH/FILE where DIR-PATH is the full path to the directory where you copied the produced Info file(s), and FILE is the name of the Info file you produced and want to install. If you don't have the `install-info' command installed, you can edit the 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: * Topic: (relative-pathname). Short description of topic. If you want to install Info files and you don't have the necessary privileges, you have several options: * Info files don't actually need to be installed before being used. You can use a prefix argument for the `info' command and specify the name of the Info file in the minibuffer. This goes to the node named `Top' in that file. For example, to view a Info file named `INFO-FILE' in your home directory, you can type this: C-u C-h i ~/INFO-FILE Alternatively, you can feed a file name to the `Info-goto-node' command (invoked by pressing in Info mode) by typing the name of the file in parentheses, like this: C-h i g (~/INFO-FILE) * You can create your own Info directory. You can tell Emacs where that Info directory is by adding its pathname to the value of the variable `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 `.emacs' file: (setq Info-default-directory-list (cons "~/Info" Info-default-directory-list)) You will need a top-level Info file named `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 `dir' files. The node lists from all `dir' files in `Info-default-directory-list' are merged by the Info system. 3.6 How do I print a Texinfo file? ================================== 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: 1. Make sure the first line of the Texinfo file looks like this: \input texinfo You may need to change `texinfo' to the full pathname of the `texinfo.tex' file, which comes with Emacs as `man/texinfo.tex' (or copy or link it into the current directory). 2. Type `texi2dvi TEXINFO-SOURCE', where TEXINFO-SOURCE is the name of the Texinfo source file for which you want to produce a printed copy. The `texi2dvi' script is part of the GNU Texinfo distribution (*note Installing Texinfo documentation::). 3. Print the DVI file `TEXINFO-SOURCE.dvi' in the normal way for printing DVI files at your site. For example, if you have a PostScript printer, run the `dvips' program to print the DVI file on that printer. To get more general instructions, retrieve the latest Texinfo package (*note Installing Texinfo documentation::). 3.7 Can I view Info files without using Emacs? ============================================== Yes. Here are some alternative programs: * `info', a stand-alone version of the Info program, comes as part of the Texinfo package. *Note Installing Texinfo documentation::, for details. * Xinfo, a stand-alone version of the Info program that runs under X Window system. You can get it at `ftp://ftp.gnu.org/pub/gnu/xinfo/xinfo-1.01.01.tar.gz' and all mirrors of `ftp.gnu.org' (see *Note Current GNU distributions::, for a list of mirrors). * Tkinfo, an Info viewer that runs under X Window system and uses Tcl/Tk. You can get Tkinfo at `http://math-www.uni-paderborn.de/~axel/tkinfo/'. 3.8 What informational files are available for Emacs? ===================================================== 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 `etc' directory of the Emacs distribution (see *Note File-name conventions::, if you're not sure where that is). `COPYING' GNU General Public License `DISTRIB' Emacs Availability Information, including the popular Free Software Foundation Order Form `FTP' How to get GNU Software by Internet FTP or by UUCP `GNU' The GNU Manifesto `INTERVIEW' Richard Stallman discusses his public-domain UNIX-compatible software system with BYTE editors `LPF' Why you should join the League for Programming Freedom `MACHINES' Status of Emacs on Various Machines and Systems `MAILINGLISTS' GNU Project Electronic Mailing Lists `NEWS' Emacs news, a history of recent user-visible changes `SERVICE' GNU Service Directory `SUN-SUPPORT' including "Using Emacstool with GNU Emacs" More GNU information, including back issues of the `GNU's Bulletin', are at `http://www.gnu.org/bulletins/bulletins.html' and `http://www.cs.pdx.edu/~trent/gnu/gnu.html' 3.9 Where can I get help in installing Emacs? ============================================= *Note Installing Emacs::, for some basic installation hints, and see *Note Problems building Emacs::, or *Note Linking with -lX11 fails::, if you have problems with the installation. The file `etc/SERVICE' (see *Note File-name 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 `ftp.gnu.org' (*note Informational files for Emacs::). 3.10 Where can I get the latest version of this FAQ? ==================================================== The Emacs FAQ is available in several ways: * Inside of Emacs itself. You can get it from selecting the `Emacs FAQ' option from the `Help' menu of the Emacs menu bar at the top of any Emacs frame, or by typing `C-h C-f' (`M-x view-emacs-FAQ'). * Via USENET. If you can read news, the FAQ should be available in your news spool, in both the `news:gnu.emacs.help' and `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 `rn', this command will do this for you at the article selection level: ?GNU Emacs Frequently Asked Questions?rc:m In Gnus, you should type `C-u C-x C-s' from the `*Summary*' buffer or `C-u ' from the `*Newsgroup*' buffer to view all articles in a newsgroup. If the FAQ articles have expired and have 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. * In the Emacs distribution. Since Emacs 18.56, the FAQ at the time of release has been part of the Emacs distribution as either `etc/FAQ' or `man/faq.texi' (*note File-name conventions::). * Via anonymous ftp and e-mail from `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 `ftp://rtfm.mit.edu/pub/usenet/comp.emacs/' and `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 `rtfm.mit.edu' mail server. The Emacs FAQ can be retrieved by sending mail to with a blank subject and containing 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 For more information, send email to with `help' and `index' in the body on separate lines. 4 Status of Emacs ***************** This chapter gives you basic information about Emacs, including its latest version status. 4.1 Where does the name "Emacs" come from? ========================================== Emacs originally was an acronym for Editor MACroS. RMS says he "picked the name Emacs because 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 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 `news:alt.lang.teco'. Someone has written a TECO implementation in Emacs Lisp (to find it, see *Note 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 the file `etc/JOKES' (*note File-name conventions::). 4.2 What is the latest version of Emacs? ======================================== Emacs 22.1 is the current version as of this writing. 4.3 What is different about Emacs 20? ===================================== To find out what has changed in recent versions, type `C-h C-n' (`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 and for mixing several languages in the same document; 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. 4.4 What is different about Emacs 21? ===================================== Emacs 21 features a thorough rewrite of the display engine. The new display engine supports variable-size fonts, images, and can play sounds on platforms which support that. As a result, the visual appearance of Emacs, when it runs on a windowed display, is much more reminiscent of modern GUI programs, and includes 3D widgets (used for the mode line and the scroll bars), a configurable and extensible toolbar, tooltips (a.k.a. balloon help), and other niceties. In addition, Emacs 21 supports faces on text-only terminals. This means that you can now have colors when you run Emacs on a GNU/Linux console and on `xterm' with `emacs -nw'. 4.5 What is different about Emacs 22? ===================================== * Emacs can be built with GTK+ widgets, and supports drag-and-drop operation on X. * Emacs 22 features support for GNU/Linux systems on S390 and x86-64 machines, as well as support for the Mac OS X and Cygwin operating systems. * The native MS-Windows, Mac OS 9 and Mac OS X builds include full support for images, toolbar, and tooltips. * Font Lock mode, Auto Compression mode, and File Name Shadow Mode are enabled by default. * The maximum size of buffers has been doubled and is 256M on 32-bit machines. * Links can be followed with `mouse-1', in addition to `mouse-2'. * Mouse wheel support is enabled by default. * Window fringes are customizable. * The mode line of the selected window is now highlighted. * The minibuffer prompt is displayed in a distinct face. * Abbrev definitions are read automatically at startup. * Grep mode is separate from Compilation mode and has many new options and commands specific to grep. * The original Emacs macro system has been replaced by the new Kmacro package, which provides many new commands and features and a simple interface that uses the function keys F3 and F4. Macros are stored in a macro ring, and can be debugged and edited interactively. * The Grand Unified Debugger (GUD) can be used with a full graphical user interface to GDB; this provides many features found in traditional development environments, making it easy to manipulate breakpoints, add watch points, display the call stack, etc. Breakpoints are visually indicated in the source buffer. * Many new modes and packages have been included in Emacs, such as Calc, TRAMP, URL, IDO, CUA, ERC, rcirc, Table, Image-Dired, SES, Ruler, Org, PGG, Flymake, Password, Printing, Reveal, wdired, t-mouse, longlines, savehist, Conf mode, Python mode, DNS mode, etc. * Leim is now part of Emacs. Unicode support has been much improved, and the following input methods have been added: belarusian, bulgarian-bds, bulgarian-phonetic, chinese-sisheng, croatian, dutch, georgian, latin-alt-postfix, latin-postfix, latin-prefix, latvian-keyboard, lithuanian-numeric, lithuanian-keyboard, malayalam-inscript, rfc1345, russian-computer, sgml, slovenian, tamil-inscript, ucs, ukrainian-computer, vietnamese-telex, and welsh. The following language environments have also been added: Belarusian, Bulgarian, Chinese-EUC-TW, Croatian, French, Georgian, Italian, Latin-6, Latin-7, Latvian, Lithuanian, Malayalam, Russian, Slovenian, Swedish, Tajik, Tamil, UTF-8, Ukrainian, Welsh, and Windows-1255. * In addition, Emacs 22 now includes the Emacs Lisp Reference Manual (*note Emacs Lisp documentation::) and the Emacs Lisp Intro. Many other changes have been made in Emacs 22, use `C-h n' to get a full list. 5 Common requests ***************** 5.1 How do I set up a `.emacs' file properly? ============================================= *note Init File: (emacs)Init File. In general, new Emacs users should not have `.emacs' files, because it causes confusing non-standard behavior. Then they send questions to asking why Emacs isn't behaving as documented. Beginning with version 20.1, Emacs includes the new Customize facility (*note Using Customize::). This allows users who are unfamiliar with Emacs Lisp to modify their `.emacs' files in a relatively straightforward way, using menus rather than Lisp code. Most packages support Customize as of this writing. While Customize might indeed make it easier to configure Emacs, consider taking a bit of time to learn Emacs Lisp and modifying your `.emacs' directly. Simple configuration options are described rather completely in *note Init File: (emacs)Init File, for users interested in performing frequently requested, basic tasks. Sometimes users are unsure as to where their `.emacs' file should be found. Visiting the file as `~/.emacs' from Emacs will find the correct file. 5.2 How do I start using Customize? =================================== The main Customize entry point is `M-x customize '. This command takes you to a buffer listing all the available Customize groups. From there, you can access all customizable options and faces, change their values, and save your changes to your init file. *note Easy Customization: (emacs)Easy Customization. If you know the name of the group in advance (e.g. "shell"), use `M-x customize-group '. If you wish to customize a single option, use `M-x customize-option '. This command prompts you for the name of the option to customize, with completion. 5.3 How do I get colors and syntax highlighting on a TTY? ========================================================= In Emacs 21.1 and later, colors and faces are supported in non-windowed mode, i.e. on Unix and GNU/Linux text-only terminals and consoles, and when invoked as `emacs -nw' on X, MS-Windows, and Mac. (Colors and faces were supported in the MS-DOS port since Emacs 19.29.) Emacs automatically detects color support at startup and uses it if available. If you think that your terminal supports colors, but Emacs won't use them, check the `termcap' entry for your display type for color-related capabilities. The command `M-x list-colors-display' pops up a window which exhibits all the colors Emacs knows about on the current display. Syntax highlighting is on by default since version 22.1. 5.4 How do I debug a `.emacs' file? =================================== Start Emacs with the `-debug-init' command-line option. This enables the Emacs Lisp debugger before evaluating your `.emacs' file, and places you in the debugger if something goes wrong. The top line in the `trace-back' buffer will be the error message, and the second or third line of that buffer will display the Lisp code from your `.emacs' file that caused the problem. You can also evaluate an individual function or argument to a function in your `.emacs' file by moving the cursor to the end of the function or argument and typing `C-x C-e' (`M-x eval-last-sexp'). Use `C-h v' (`M-x describe-variable') to check the value of variables which you are trying to set or use. 5.5 How do I make Emacs display the current line (or column) number? ==================================================================== To have Emacs automatically display the current line number of the point in the mode line, do `M-x line-number-mode'. You can also put the form (setq line-number-mode t) in your `.emacs' file to achieve this whenever you start Emacs. (Line number display is on by default, unless your site-specific initialization disables it.) Note that Emacs will not display the line number if the buffer's size in bytes is larger than the value of the variable `line-number-display-limit'. You can similarly display the current column with `M-x column-number-mode', or by putting the form (setq column-number-mode t) in your `.emacs' file. The `"%c"' format specifier in the variable `mode-line-format' will insert the current column's value into the mode line. See the documentation for `mode-line-format' (using `C-h v mode-line-format ') for more information on how to set and use this variable. Users of all Emacs versions can display the current column using the `column' package written by Per Abrahamsen . *Note 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). The `setnu' package written by Kyle Jones provides this feature. So too does `wb-line-number', written by Naoki Nakamura . 5.6 How can I modify the titlebar to contain the current file name? =================================================================== The contents of an Emacs frame's titlebar is controlled by the variable `frame-title-format', which has the same structure as the variable `mode-line-format'. (Use `C-h v' or `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 Emacs invocation name and the name of the machine at which Emacs was invoked. This is done by setting `frame-title-format' to the default value of (multiple-frames "%b" ("" invocation-name "@" system-name)) 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 `.emacs': (setq frame-title-format "%b") 5.7 How do I turn on abbrevs by default just in mode MYMODE? ============================================================ Put this in your `.emacs' file: (condition-case () (quietly-read-abbrev-file) (file-error nil)) (add-hook 'MYMODE-mode-hook (lambda () (setq abbrev-mode t))) Starting with Emacs 22, the standard abbrevs file is read automatically at startup, so the first of these two forms becomes unnecessary. 5.8 How do I make Emacs use a certain major mode for certain files? =================================================================== If you want to use a certain mode FOO for all files whose names end with the extension `.BAR', this will do it for you: (setq auto-mode-alist (cons '("\\.BAR\\'" . FOO-mode) auto-mode-alist)) Otherwise put this somewhere in the first line of any file you want to edit in the mode FOO (in the second line, if the first line begins with `#!'): -*- FOO -*- Beginning with Emacs 19, the variable `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 script.) This feature only applies when the file name doesn't indicate which mode to use. Use `C-h v' (or `M-x describe-variable') on `interpreter-mode-alist' to learn more. 5.9 How can I highlight a region of text in Emacs? ================================================== You can cause the region to be highlighted when the mark is active by including (transient-mark-mode t) in your `.emacs' file. 5.10 How can I replace highlighted text with what I type? ========================================================= Use `delete-selection-mode', which you can start automatically by placing the following Lisp form in your `.emacs' file: (delete-selection-mode 1) According to the documentation string for `delete-selection-mode' (which you can read using `M-x describe-function delete-selection-mode '): When ON, typed text replaces the selection if the selection is active. When OFF, typed text is just inserted at point. This mode also allows you to delete (not kill) the highlighted region by pressing . 5.11 How do I control Emacs's case-sensitivity when searching/replacing? ======================================================================== For searching, the value of the variable `case-fold-search' determines whether they are case sensitive: (setq case-fold-search nil) ; make searches case sensitive (setq case-fold-search t) ; make searches case insensitive Similarly, for replacing, the variable `case-replace' determines whether replacements preserve case. You can also toggle case sensitivity at will in isearch with `M-c'. To change the case sensitivity just for one major mode, use the major mode's hook. For example: (add-hook 'FOO-mode-hook (lambda () (setq case-fold-search nil))) 5.12 How do I search for, delete, or replace unprintable (eight-bit or control) characters? =========================================================================================== To search for a single character that appears in the buffer as, for example, `\237', you can type `C-s C-q 2 3 7'. (This assumes the value of `search-quote-char' is 17 (i.e., `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. * Regexp for the printable chars: `[\t\n\r\f -~]' * Regexp for the unprintable chars: `[^\t\n\r\f -~]' To type these special characters in an interactive argument to `isearch-forward-regexp' or `re-search-forward', you need to use `C-q'. (`\t', `\n', `\r', and `\f' stand respectively for , , , and `C-l'.) So, to search for unprintable characters using `re-search-forward': `M-x re-search-forward [^ C-q C-q C-q C-l -~] ' Using `isearch-forward-regexp': `C-M-s [^ C-q C-q C-l -~]' To delete all unprintable characters, simply use replace-regexp: `M-x replace-regexp [^ C-q C-q C-q C-l -~] ' Replacing is similar to the above. To replace all unprintable characters with a colon, use: M-x replace-regexp [^ C-q C-q C-q C-l -~] : 5.13 How do I input a newline character in isearch or query-replace? ==================================================================== Use `C-q C-j'. For more information, see *note Special Input for Incremental Search: (emacs)Special Isearch. 5.14 How do I copy text from the kill ring into the search string? ================================================================== Use `M-y'. *note Isearch Yanking: (emacs)Isearch Yank. 5.15 How do I make Emacs wrap words for me? =========================================== Use `auto-fill-mode', activated by typing `M-x auto-fill-mode'. The default maximum line width is 70, determined by the variable `fill-column'. To learn how to turn this on automatically, see *Note Turning on auto-fill by default::. 5.16 How do I turn on `auto-fill-mode' by default? ================================================== To turn on `auto-fill-mode' just once for one buffer, use `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 `auto-fill' mode for all text buffers, including the following in your `.emacs' file: (add-hook 'text-mode-hook 'turn-on-auto-fill) If you want `auto-fill' mode on in all major modes, do this: (setq-default auto-fill-function 'do-auto-fill) 5.17 Where can I get a better spelling checker for Emacs? ========================================================= Use Ispell. *Note Ispell::. 5.18 How can I spell-check TeX or *roff documents? ================================================== Use Ispell. Ispell can handle TeX and *roff documents. *Note Ispell::. 5.19 How do I change `load-path'? ================================= In general, you should only add to the `load-path'. You can add directory /DIR/SUBDIR to the load path like this: (setq load-path (cons "/dir/subdir/" load-path)) To do this relative to your home directory: (setq load-path (cons "~/mysubdir/" load-path)) 5.20 How do I use an already running Emacs from another window? =============================================================== `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. * Setup: Emacs must have executed the `server-start' function for `emacsclient' to work. This can be done either by a command line option: emacs -f server-start or by invoking `server-start' from `.emacs': (if (SOME CONDITIONS ARE MET) (server-start)) When this is done, Emacs creates a Unix domain socket named `server' in `/tmp/emacsUSERID'. See `server-socket-dir'. To get your news reader, mail reader, etc., to invoke `emacsclient', try setting the environment variable `EDITOR' (or sometimes `VISUAL') to the value `emacsclient'. You may have to specify the full pathname of the `emacsclient' program instead. Examples: # csh commands: setenv EDITOR emacsclient # using full pathname setenv EDITOR /usr/local/emacs/etc/emacsclient # sh command: EDITOR=emacsclient ; export EDITOR * Normal use: When `emacsclient' is run, it connects to the socket and passes its command line options to Emacs, 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 `C-x #' (or `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. There is an enhanced version of `emacsclient' called `gnuserv', written by Andy Norman (*note Packages that do not come with Emacs::). `gnuserv' uses Internet domain sockets, so it can work across most network connections. The most recent `gnuserv' package is available at `http://meltin.net/hacks/emacs/' 5.21 How do I make Emacs recognize my compiler's funny error messages? ====================================================================== Customize the `compilation-error-regexp-alist' variable. 5.22 How do I change the indentation for `switch'? ================================================== Many people want to indent their `switch' statements like this: f() { switch(x) { case A: x1; break; case B: x2; break; default: x3; } } The solution at first appears to be: set `c-indent-level' to 4 and `c-label-offset' to -2. However, this will give you an indentation spacing of four instead of two. The _real_ solution is to use `cc-mode' (the default mode for C programming in Emacs 20 and later) and add the following line to your `.emacs': (c-set-offset 'case-label '+) There appears to be no way to do this with the old `c-mode'. 5.23 How to customize indentation in C, C++, and Java buffers? ============================================================== The Emacs `cc-mode' features an interactive procedure for customizing the indentation style, which is fully explained in the `CC Mode' manual that is part of the Emacs distribution, see *Note Customization Indentation: (ccmode)Customizing Indentation. Here's a short summary of the procedure: 1. Go to the beginning of the first line where you don't like the indentation and type `C-c C-o'. Emacs will prompt you for the syntactic symbol; type to accept the default it suggests. 2. Emacs now prompts for the offset of this syntactic symbol, showing the default (the current definition) inside parentheses. You can choose one of these: `0' No extra indentation. `+' Indent one basic offset. `-' Outdent one basic offset. `++' Indent two basic offsets `--' Outdent two basic offsets. `*' Indent half basic offset. `/' Outdent half basic offset. 3. After choosing one of these symbols, type `C-c C-q' to reindent the line or the block according to what you just specified. 4. If you don't like the result, go back to step 1. Otherwise, add the following line to your `.emacs': (c-set-offset 'SYNTACTIC-SYMBOL OFFSET) where SYNTACTIC-SYMBOL is the name Emacs shows in the minibuffer when you type `C-c C-o' at the beginning of the line, and OFFSET is one of the indentation symbols listed above (`+', `/', `0', etc.) that you've chosen during the interactive procedure. 5. Go to the next line whose indentation is not to your liking and repeat the process there. It is recommended to put all the resulting `(c-set-offset ...)' customizations inside a C mode hook, like this: (defun my-c-mode-hook () (c-set-offset ...) (c-set-offset ...)) (add-hook 'c-mode-hook 'my-c-mode-hook) Using `c-mode-hook' avoids the need to put a `(require 'cc-mode)' into your `.emacs' file, because `c-set-offset' might be unavailable when `cc-mode' is not loaded. Note that `c-mode-hook' runs for C source files only; use `c++-mode-hook' for C++ sources, `java-mode-hook' for Java sources, etc. If you want the same customizations to be in effect in _all_ languages supported by `cc-mode', use `c-mode-common-hook'. 5.24 How can I make Emacs automatically scroll horizontally? ============================================================ In Emacs 21 and later, this is on by default: if the variable `truncate-lines' is non-`nil' in the current buffer, Emacs automatically scrolls the display horizontally when point moves off the left or right edge of the window. Note that this is overridden by the variable `truncate-partial-width-windows' if that variable is non-nil and the current buffer is not full-frame width. In Emacs 20, use the `hscroll-mode'. Here is some information from the documentation, available by typing `C-h f hscroll-mode ': Automatically scroll horizontally when the point moves off the left or right edge of the window. - Type `M-x hscroll-mode' to enable it in the current buffer. - Type `M-x hscroll-global-mode' to enable it in every buffer. - `turn-on-hscroll' is useful in mode hooks as in: (add-hook 'text-mode-hook 'turn-on-hscroll) - `hscroll-margin' controls how close the cursor can get to the edge of the window. - `hscroll-step-percent' controls how far to jump once we decide to do so. 5.25 How do I make Emacs "typeover" or "overwrite" instead of inserting? ======================================================================== `M-x overwrite-mode' (a minor mode). This toggles `overwrite-mode' on and off, so exiting from `overwrite-mode' is as easy as another `M-x overwrite-mode'. On some systems, toggles `overwrite-mode' on and off. 5.26 How do I stop Emacs from beeping on a terminal? ==================================================== 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 `TERMCAP' environment variable (assuming you have one): ... :vb=: ... And evaluate the following Lisp form: (setq visible-bell t) 5.27 How do I turn down the bell volume in Emacs running under X? ================================================================= On X Window system, you can adjust the bell volume and duration for all programs with the shell command `xset'. Invoking `xset' without any arguments produces some basic information, including the following: 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 5.28 How do I tell Emacs to automatically indent a new line to the indentation of the previous line? ==================================================================================================== Such behavior is automatic in Emacs 20 and later. From the `etc/NEWS' file for Emacs 20.2: ** 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). in Text mode now runs the command `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. If you have `auto-fill-mode' turned on (*note 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 `C-x .' (`set-fill-prefix') to set the fill prefix. Thereafter, auto-filling will automatically put the fill prefix at the beginning of new lines, and `M-q' (`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. There are many packages available to deal with this (*note Packages that do not come with Emacs::). Look for "fill" and "indent" keywords for guidance. 5.29 How do I show which parenthesis matches the one I'm looking at? ==================================================================== Call `show-paren-mode' in your `.emacs' file: (show-paren-mode 1) You can also enable this mode by selecting the `Paren Match Highlighting' option from the `Options' menu of the Emacs menu bar at the top of any Emacs frame. Alternatives to this mode include: * If you're looking at a right parenthesis (or brace or bracket) you can delete it and reinsert it. Emacs will momentarily move the cursor to the matching parenthesis. * `C-M-f' (`forward-sexp') and `C-M-b' (`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 table.) * Here is some Emacs Lisp that will make the <%> key show the matching parenthesis, like in `vi'. In addition, if the cursor isn't over a parenthesis, it simply inserts a % like normal. ;; 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))))) 5.30 In C mode, can I show just the lines that will be left after `#ifdef' commands are handled by the compiler? ================================================================================================================ `M-x hide-ifdef-mode'. (This is a minor mode.) You might also want to investigate `cpp.el', which is distributed with Emacs. 5.31 How do I repeat a command as many times as possible? ========================================================= As of Emacs 20.3, there is indeed a `repeat' command (`C-x z') 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 `C-x ' (`repeat-complex-command') to reinvoke commands that used the minibuffer to get arguments. In `repeat-complex-command' you can type `M-p' and `M-n' (and also up-arrow and down-arrow, if your keyboard has these keys) to scan through all the different complex commands you've typed. To repeat a set of commands, use keyboard macros. Use `C-x (' and `C-x )' to make a keyboard macro that invokes the command and then type `C-x e'. (*note Keyboard Macros: (emacs)Keyboard Macros.) If you're really desperate for the `.' command in `vi' that redoes the last insertion/deletion, use VIPER, a `vi' emulation mode which comes with Emacs, and which appears to support it. (*Note VIPER::.) 5.32 What are the valid X resource settings (i.e., stuff in .Xdefaults)? ======================================================================== *note X Resources: (emacs)X Resources. 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. 5.33 How do I execute ("evaluate") a piece of Emacs Lisp code? ============================================================== There are a number of ways to execute ("evaluate", in Lisp lingo) an Emacs Lisp "form": * If you want it evaluated every time you run Emacs, put it in a file named `.emacs' in your home directory. This is known as "your `.emacs' file," and contains all of your personal customizations. * You can type the form in the `*scratch*' buffer, and then type (or `C-j') after it. The result of evaluating the form will be inserted in the buffer. * In `emacs-lisp-mode', typing `C-M-x' evaluates a top-level form before or around point. * Typing `C-x C-e' in any buffer evaluates the Lisp form immediately before point and prints its value in the echo area. * Typing `M-:' or `M-x eval-expression' allows you to type a Lisp form in the minibuffer which will be evaluated once you press . * You can use `M-x load-file' to have Emacs evaluate all the Lisp forms in a file. (To do this from Lisp use the function `load' instead.) The functions `load-library', `eval-region', `eval-buffer', `require', and `autoload' are also useful; see *Note Emacs Lisp documentation::, if you want to learn more about them. 5.34 How do I change Emacs's idea of the character's length? ================================================================== Set the variable `default-tab-width'. For example, to set stops every 10 characters, insert the following in your `.emacs' file: (setq default-tab-width 10) Do not confuse variable `tab-width' with variable `tab-stop-list'. The former is used for the display of literal characters. The latter controls what characters are inserted when you press the character in certain modes. 5.35 How do I insert at the beginning of every line? ================================================================ To do this to an entire buffer, type `M-< M-x replace-regexp ^ your text '. To do this to a region, use `string-insert-rectangle'. Set the mark (`C-') at the beginning of the first line you want to prefix, move the cursor to last line to be prefixed, and type `M-x string-insert-rectangle '. To do this for the whole buffer, type `C-x h M-x string-insert-rectangle '. If you are trying to prefix a yanked mail message with `>', you might want to set the variable `mail-yank-prefix'. In Message buffers, you can even use `M-;' to cite yanked messages (`M-;' runs the function `comment-region', it is a general-purpose mechanism to comment regions) (*note Changing the included text prefix::). 5.36 How do I insert `_^H' before each character in a region to get an underlined paragraph? ============================================================================================ Mark the region and then type `M-x underline-region '. 5.37 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? ========================================================================================================================================= Use `M-x picture-mode'. See also the variable `track-eol' and the command `set-goal-column' bound to `C-x C-n' (*note Moving Point: (emacs)Moving Point.). 5.38 How do I tell Emacs to iconify itself? =========================================== `C-z' iconifies Emacs when running under X and suspends Emacs otherwise. *note Frame Commands: (emacs)Frame Commands. 5.39 How do I use regexps (regular expressions) in Emacs? ========================================================= *note Regexp Backslash: (emacs)Regexp Backslash. The `or' operator is `\|', not `|', and the grouping operators are `\(' and `\)'. Also, the string syntax for a backslash is `\\'. To specify a regular expression like `xxx\(foo\|bar\)' in a Lisp string, use `xxx\\(foo\\|bar\\)'. Note the doubled backslashes! * Unlike in Unix `grep', `sed', etc., a complement character set (`[^...]') can match a newline character ( a.k.a. `C-j' a.k.a. `\n'), unless newline is mentioned as one of the characters not to match. * The character syntax regexps (e.g., `\sw') are not meaningful inside character set regexps (e.g., `[aeiou]'). (This is actually typical for regexp syntax.) 5.40 How do I perform a replace operation across more than one file? ==================================================================== As of Emacs 19.29, Dired mode (`M-x dired ', or `C-x d') supports the command `dired-do-query-replace' (`Q'), which allows users to replace regular expressions in multiple files. You can use this command to perform search/replace operations on multiple files by following the following steps: * Assemble a list of files you want to operate on with either `find-dired', `find-name-dired' or `find-grep-dired'. * Mark all files in the resulting Dired buffer using `t'. * Use `Q' to start a `query-replace-regexp' session on the marked files. * To accept all replacements in each file, hit `!'. Another way to do the same thing is to use the "tags" feature of Emacs: it includes the command `tags-query-replace' which performs a query-replace across all the files mentioned in the `TAGS' file. *note Tags Search: (emacs)Tags Search. 5.41 Where is the documentation for `etags'? ============================================ The `etags' man page should be in the same place as the `emacs' man page. Quick command-line switch descriptions are also available. For example, `etags -H'. 5.42 How do I disable backup files? =================================== You probably don't want to do this, since backups are useful, especially when something goes wrong. To avoid seeing backup files (and other "uninteresting" files) in Dired, load `dired-x' by adding the following to your `.emacs' file: (add-hook 'dired-load-hook (lambda () (load "dired-x"))) With `dired-x' loaded, `M-o' toggles omitting in each dired buffer. You can make omitting the default for new dired buffers by putting the following in your `.emacs': (add-hook 'dired-mode-hook 'dired-omit-toggle) 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 from `ftp.gnu.org' and its mirrors (*note Current GNU distributions::). To disable or change the way backups are made, *note (emacs)Backup Names::. Beginning with Emacs 21.1, you can control where Emacs puts backup files by customizing the variable `backup-directory-alist'. This variable's value specifies that files whose names match specific patters should have their backups put in certain directories. A typical use is to add the element `("." . DIR)' to force Emacs to put *all* backup files in the directory `dir'. 5.43 How do I disable `auto-save-mode'? ======================================= 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 `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 `auto-save' package (*note Packages that do not come with Emacs::). This package also allows you to place all auto-save files in one directory, such as `/tmp'. To disable or change how `auto-save-mode' works, *note (emacs)Auto Save::. 5.44 How can I go to a certain line given its number? ===================================================== Are you sure you indeed need to go to a line by its number? Perhaps all you want is to display a line in your source file for which a compiler printed an error message? If so, compiling from within Emacs using the `M-x compile' and `M-x recompile' commands is a much more effective way of doing that. Emacs automatically intercepts the compile error messages, inserts them into a special buffer called `*compilation*', and lets you visit the locus of each message in the source. Type `C-x `' to step through the offending lines one by one (starting with Emacs 22, you can also use `M-g M-p' and `M-g M-n' to go to the previous and next matches directly). Click `Mouse-2' or press on a message text in the `*compilation*' buffer to go to the line whose number is mentioned in that message. But if you indeed need to go to a certain text line, type `M-g M-g' (which is the default binding of the `goto-line' function starting with Emacs 22). Emacs will prompt you for the number of the line and go to that line. You can do this faster by invoking `goto-line' with a numeric argument that is the line's number. For example, `C-u 286 M-g M-g' will jump to line number 286 in the current buffer. 5.45 How can I create or modify new pull-down menu options? =========================================================== Each menu title (e.g., `File', `Edit', `Buffers') 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' item to the `Edit' menu thus requires the following Lisp code: (define-key global-map [menu-bar edit forward] '("Forward word" . forward-word)) The first line adds the entry to the global keymap, which includes global menu bar entries. Replacing the reference to `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: (define-key global-map [menu-bar words] (cons "Words" (make-sparse-keymap "Words"))) 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' item to this new menu would thus require the following code: (define-key global-map [menu-bar words forward] '("Forward word" . forward-word)) 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), the 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 `define-key-after', which works the same as `define-key', but lets you modify where items appear. The following Lisp code would insert the `Forward Word' item in the `Edit' menu immediately following the `Undo' item: (define-key-after (lookup-key global-map [menu-bar edit]) [forward] '("Forward word" . forward-word) 'undo) Note how the second and third arguments to `define-key-after' are different from those of `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 `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 "Menu Keymaps." (*Note Emacs Lisp documentation::, for information on this manual.) 5.46 How do I delete menus and menu options? ============================================ The simplest way to remove a menu is to set its keymap to `nil'. For example, to delete the `Words' menu (*note Modifying pull-down menus::), use: (define-key global-map [menu-bar words] nil) Similarly, removing a menu option requires redefining a keymap entry to `nil'. For example, to delete the `Forward word' menu option from the `Edit' menu (we added it in *Note Modifying pull-down menus::), use: (define-key global-map [menu-bar edit forward] nil) 5.47 How do I turn on syntax highlighting? ========================================== `font-lock-mode' is the standard way to have Emacs perform syntax highlighting in the current buffer. It is enabled by default in Emacs 22.1 and later. With `font-lock-mode' turned on, different types of text will appear in different colors. For instance, 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 `hilit19.el' comes with the stock Emacs distribution. It is no longer maintained. To turn `font-lock-mode' off within an existing buffer, use `M-x font-lock-mode '. In Emacs 21 and earlier versions, you could use the following code in your `.emacs' file to turn on `font-lock-mode' globally: (global-font-lock-mode 1) Highlighting a buffer with `font-lock-mode' can take quite a while, and cause an annoying delay in display, so several features exist to work around this. In Emacs 21 and later, turning on `font-lock-mode' automatically activates the new "Just-In-Time fontification" provided by `jit-lock-mode'. `jit-lock-mode' defers the fontification of portions of buffer until you actually need to see them, and can also fontify while Emacs is idle. This makes display of the visible portion of a buffer almost instantaneous. For details about customizing `jit-lock-mode', type `C-h f jit-lock-mode '. In versions of Emacs before 21, different levels of decoration are available, from slight to gaudy. More decoration means you need to wait more time for a buffer to be fontified (or a faster machine). To control how decorated your buffers should become, set the value of `font-lock-maximum-decoration' in your `.emacs' file, with a `nil' value indicating default (usually minimum) decoration, and a `t' value indicating the maximum decoration. For the gaudiest possible look, then, include the line (setq font-lock-maximum-decoration t) in your `.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 `font-lock-maximum-decoration' with `C-h v' (or `M-x describe-variable '). Also see the documentation for the function `font-lock-mode', available by typing `C-h f font-lock-mode' (`M-x describe-function font-lock-mode '). To print buffers with the faces (i.e., colors and fonts) intact, use `M-x ps-print-buffer-with-faces' or `M-x ps-print-region-with-faces'. You will need a way to send text to a PostScript printer, or a PostScript interpreter such as Ghostscript; consult the documentation of the variables `ps-printer-name', `ps-lpr-command', and `ps-lpr-switches' for more details. 5.48 How can I force Emacs to scroll only one line when I move past the bottom of the screen? ============================================================================================= Customize the `scroll-conservatively' variable with `M-x customize-variable scroll-conservatively ' and set it to a large value like, say, 10000. For an explanation of what this means, *note Auto Scrolling: (emacs)Auto Scrolling. Alternatively, use the following Lisp form in your `.emacs': (setq scroll-conservatively most-positive-fixnum) 5.49 How can I edit MS-DOS files using Emacs? ============================================= 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, the mode line will indicate that it is a DOS file. On Unix and GNU/Linux systems, and also on a Macintosh, the string `(DOS)' will appear near the left edge of the mode line; on DOS and Windows, where the DOS end-of-line (EOL) format is the default, a backslash (`\') will appear in the mode line. If you are running a version of Emacs before 20.1, get `crypt++' (*note Packages that do not come with Emacs::). Among other things, `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. 5.50 How can I tell Emacs to fill paragraphs with a single space after each period? =================================================================================== Add the following line to your `.emacs' file: (setq sentence-end-double-space nil) 5.51 Why these strange escape sequences from `ls' from the Shell mode? ====================================================================== This happens because `ls' is aliased to `ls --color' in your shell init file. You have two alternatives to solve this: * Make the alias conditioned on the `EMACS' variable in the environment. When Emacs runs a subsidiary shell, it exports the `EMACS' variable to that shell, with value equal to the absolute file name of Emacs. You can unalias `ls' when that happens, thus limiting the alias to your interactive sessions. * Install the `ansi-color' package (bundled with Emacs 21.1 and later), which converts these ANSI escape sequences into colors. 5.52 How can I start Emacs in fullscreen mode on MS-Windows? ============================================================ Use the function `w32-send-sys-command'. For example, you can put the following in your `.emacs' file: (add-hook 'term-setup-hook #'(lambda () (w32-send-sys-command ?\xF030))) To avoid the slightly distracting visual effect of Emacs starting with its default frame size and then growing to fullscreen, you can add an `Emacs.Geometry' entry to the Windows registry settings (see *note (emacs)X Resources::). To compute the correct values for width and height, first maximize the Emacs frame and then evaluate `(frame-height)' and `(frame-width)' with `M-:'. 6 Bugs and problems ******************* The Emacs manual lists some common kinds of trouble users could get into, see *Note Dealing with Emacs Trouble: (emacs)Lossage, so you might look there if the problem you encounter isn't described in this chapter. If you decide you've discovered a bug, see *Note Reporting Bugs: (emacs)Bugs, for instructions how to do that. The file `etc/PROBLEMS' in the Emacs distribution lists various known problems with building and using Emacs on specific platforms; type `C-h C-e' to read it. 6.1 Does Emacs have problems with files larger than 8 megabytes? ================================================================ Old versions (i.e., anything before 19.29) of Emacs had problems editing files larger than 8 megabytes. In versions 19.29 and later, the maximum buffer size is at least 2^27-1, or 134,217,727 bytes, or 132 MBytes. And in Emacs 22, the maximum buffer size has been increased to 268,435,455 bytes (or 256 MBytes) on 32-bit machines. 6.2 How do I get rid of `^M' or echoed commands in my shell buffer? =================================================================== Try typing `M-x shell-strip-ctrl-m ' while in `shell-mode' to make them go away. If that doesn't work, you have several options: For `tcsh', put this in your `.cshrc' (or `.tcshrc') file: if ($?EMACS) then if ("$EMACS" =~ /*) then if ($?tcsh) unset edit stty nl endif endif Or put this in your `.emacs_tcsh' or `~/.emacs.d/init_tcsh.sh' file: unset edit stty nl Alternatively, use `csh' in your shell buffers instead of `tcsh'. One way is: (setq explicit-shell-file-name "/bin/csh") and another is to do this in your `.cshrc' (or `.tcshrc') file: setenv ESHELL /bin/csh (You must start Emacs over again with the environment variable properly set for this to take effect.) You can also set the `ESHELL' environment variable in Emacs Lisp with the following Lisp form, (setenv "ESHELL" "/bin/csh") The above solutions try to prevent the shell from producing the `^M' characters in the first place. If this is not possible (e.g., if you use a Windows shell), you can get Emacs to remove these characters from the buffer by adding this to your `.emacs' init file: (add-hook 'comint-output-filter-functions 'shell-strip-ctrl-m) On a related note: if your shell is echoing your input line in the shell buffer, you might want to customize the `comint-process-echoes' variable in your shell buffers, or try the following command in your shell start-up file: stty -icrnl -onlcr -echo susp ^Z 6.3 Why do I get "Process shell exited abnormally with code 1"? =============================================================== The most likely reason for this message is that the `env' program is not properly installed. Compile this program for your architecture, and install it with `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 `exec-directory' by typing `C-h v exec-directory '.) You should also check for other programs named `env' in your path (e.g., SunOS has a program named `/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 `make clean' command will remove `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 `PROBLEMS' (in the `etc' subdirectory of the top-level directory when you unpack the Emacs source) for other possible causes of this message. 6.4 Why do I get an error message when I try to run `M-x shell'? ================================================================ On MS-Windows, this might happen because Emacs tries to look for the shell in a wrong place. The default file name `/bin/sh' is usually incorrect for non-Unix systems. If you know where your shell executable is, set the variable `explicit-shell-file-name' in your `.emacs' file to point to its full file name, like this: (setq explicit-shell-file-name "d:/shells/bash.exe") If you don't know what shell does Emacs use, try the `M-!' command; if that works, put the following line into your `.emacs': (setq explicit-shell-file-name shell-file-name) Some people have trouble with Shell Mode because of intrusive antivirus software; disabling the resident antivirus program solves the problems in those cases. 6.5 Where is the termcap/terminfo entry for terminal type `emacs'? ================================================================== The termcap entry for terminal type `emacs' is ordinarily put in the `TERMCAP' environment variable of subshells. It may help in certain situations (e.g., using rlogin from shell buffer) to add an entry for `emacs' to the system-wide termcap file. Here is a correct termcap entry for `emacs': emacs:tc=unknown: To make a terminfo entry for `emacs', use `tic' or `captoinfo'. You need to generate `/usr/lib/terminfo/e/emacs'. It may work to simply copy `/usr/lib/terminfo/d/dumb' to `/usr/lib/terminfo/e/emacs'. Having a termcap/terminfo entry will not enable the use of full screen programs in shell buffers. Use `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: if ("$term" == emacs) set term=dumb 6.6 Why does Emacs spontaneously start displaying `I-search:' and beeping? ========================================================================== Your terminal (or something between your terminal and the computer) is sending `C-s' and `C-q' for flow control, and Emacs is receiving these characters and interpreting them as commands. (The `C-s' character normally invokes the `isearch-forward' command.) For possible solutions, see *Note Handling C-s and C-q with flow control::. 6.7 Why can't Emacs talk to certain hosts (or certain hostnames)? ================================================================= The problem may be that Emacs is linked with a wimpier version of `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 `DISPLAY' environment variable." or a message of "Unknown host" from `open-network-stream'. On a Sun, this may be because Emacs had to be linked with the static C library. The version of `gethostbyname' in the static C library may only look in `/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 `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: * Explicitly add the host you want to communicate with to `/etc/hosts'. * Relink Emacs with this line in `src/config.h': #define LIBS_SYSTEM -lresolv * Replace `gethostbyname' and friends in `libc.a' with more useful versions such as the ones in `libresolv.a'. Then relink Emacs. * If you are actually running NIS, make sure that `ypbind' is properly told to do DNS lookups with the correct command line switch. 6.8 Why does Emacs say `Error in init file'? ============================================ An error occurred while loading either your `.emacs' file or the system-wide file `lisp/default.el'. Emacs 21.1 and later pops the `*Messages*' buffer, and puts there some additional information about the error, to provide some hints for debugging. For information on how to debug your `.emacs' file, see *Note 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 *Note Terminal setup code works after Emacs has begun::. 6.9 Why does Emacs ignore my X resources (my .Xdefaults file)? ============================================================== As of version 19, Emacs searches for X resources in the files specified by the following environment variables: * `XFILESEARCHPATH' * `XUSERFILESEARCHPATH' * `XAPPLRESDIR' This emulates the functionality provided by programs written using the Xt toolkit. `XFILESEARCHPATH' and `XUSERFILESEARCHPATH' should be a list of file names separated by colons. `XAPPLRESDIR' should be a list of directory names separated by colons. Emacs searches for X resources: 1. specified on the command line, with the `-xrm RESOURCESTRING' option, 2. then in the value of the `XENVIRONMENT' environment variable, - or if that is unset, in the file named `~/.Xdefaults-HOSTNAME' if it exists (where HOSTNAME is the name of the machine Emacs is running on), 3. then in the screen-specific and server-wide resource properties provided by the server, - or if those properties are unset, in the file named `~/.Xdefaults' if it exists, 4. then in the files listed in `XUSERFILESEARCHPATH', - or in files named `LANG/Emacs' in directories listed in `XAPPLRESDIR' (where LANG is the value of the `LANG' environment variable), if the `LANG' environment variable is set, - or in files named Emacs in the directories listed in `XAPPLRESDIR' - or in `~/LANG/Emacs' (if the `LANG' environment variable is set), - or in `~/Emacs', 5. then in the files listed in `XFILESEARCHPATH'. 6.10 Why don't my customizations of the frame parameters work? ============================================================== This probably happens because you have set the frame parameters in the variable `initial-frame-alist'. That variable holds parameters used only for the first frame created when Emacs starts. To customize the parameters of all frames, change the variable `default-frame-alist' instead. These two variables exist because many users customize the initial frame in a special way. For example, you could determine the position and size of the initial frame, but would like to control the geometry of the other frames by individually positioning each one of them. 6.11 Why does Emacs take 20 seconds to visit a file? ==================================================== Old versions of Emacs (i.e., versions before Emacs 20.x) often encountered this when the master lock file, `!!!SuperLock!!!', has been left in the lock directory somehow. Delete it. 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 `CLASH_DETECTION' undefined. 6.12 How do I edit a file with a `$' in its name? ================================================= When entering a file name in the minibuffer, Emacs will attempt to expand a `$' followed by a word as an environment variable. To suppress this behavior, type `$$' instead. 6.13 Why does shell mode lose track of the shell's current directory? ===================================================================== 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 `cd' commands. If you type `cd' followed by a directory name with a variable reference (`cd $HOME/bin') or with a shell metacharacter (`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 (*note Finding a package with particular functionality::). You can tell Emacs the shell's current directory with the command `M-x dirs'. 6.14 Are there any security risks in Emacs? =========================================== * The `movemail' incident. (No, this is not a risk.) In his book `The Cuckoo's Egg', Cliff Stoll describes this in chapter 4. The site at LBL had installed the `/etc/movemail' program setuid root. (As of version 19, `movemail' is in your architecture-specific directory; type `C-h v exec-directory ' to see what it is.) Since `movemail' had not been designed for this situation, a security hole was created and users could get root privileges. `movemail' has since been changed so that this security hole will not exist, even if it is installed setuid root. However, `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. * The `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. As of Emacs 22, Emacs has a list of local variables that are known to be safe to set. If a file tries to set any variable outside this list, 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 `enable-local-eval'. For more information, *note File Variables: (emacs)File Variables. * Synthetic X events. (Yes, a risk; use `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 `MIT-MAGIC-COOKIE-1'. If using the `xauth' program has any effect, then you are probably using `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 _does not eliminate the risk_. On most computers running Unix and X, you enable and disable access using the `xhost' command. To allow all hosts access to your X server, use xhost + at the shell prompt, which (on an HP machine, at least) produces the following message: access control disabled, clients can connect from any host To deny all hosts access to your X server (except those explicitly allowed by name), use xhost - On the test HP computer, this command generated the following message: access control enabled, only authorized clients can connect 6.15 Dired says, `no file on this line' when I try to do something. =================================================================== 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 `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, `directory-listing-before-filename-regexp'. 7 Compiling and installing Emacs ******************************** 7.1 How do I install 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 *Note Emacs for MS-DOS::, which describe where to get non-Unix source and binaries, and how to install Emacs on those systems. For Unix and Unix-like systems, the easiest way is often to compile it from scratch. You will need: * Emacs sources. *Note Current GNU distributions::, for a list of ftp sites that make them available. On `ftp.gnu.org', the main GNU distribution site, sources are available as `ftp://ftp.gnu.org/pub/gnu/emacs/emacs-22.1.tar.gz' The above will obviously change as new versions of Emacs come out. For instance, when Emacs 22.42 is released, it will most probably be available as `ftp://ftp.gnu.org/pub/gnu/emacs/emacs-22.42.tar.gz' Again, you should use one of the GNU mirror sites (see *Note Current GNU distributions::, and adjust the URL accordingly) so as to reduce load on `ftp.gnu.org'. * `gzip', the GNU compression utility. You can get `gzip' via anonymous ftp at mirrors of `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 gunzip --verbose emacs-22.1.tar.gz changing the Emacs version (22.1), as necessary. Once `gunzip' has finished doing its job, a file by the name of `emacs-22.1.tar' should be in your build directory. * `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 `tar' before you can build Emacs. Typically, the extraction command would look like tar -xvvf emacs-22.1.tar The `x' indicates that we want to extract files from this tarfile, the two `v's force verbose output, and the `f' tells `tar' to use a disk file, rather than one on the tape drive. If you're using GNU `tar' (available at mirrors of `ftp.gnu.org'), you can combine this step and the previous one by using the command tar -zxvvf emacs-22.1.tar.gz The additional `z' at the beginning of the options list tells GNU `tar' to uncompress the file with `gunzip' before extracting the tarfile's components. At this point, the Emacs sources (all 70+ megabytes of them) should be sitting in a directory called `emacs-22.1'. On most common Unix and Unix-like systems, you should be able to compile Emacs (with X Window system support) with the following commands: cd emacs-22.1 # change directory to emacs-22.1 ./configure # configure Emacs for your particular system make # use Makefile to build components, then Emacs If the `make' completes successfully, the odds are fairly good that the build has gone well. (*Note Problems building Emacs::, if you weren't successful.) By default, Emacs is installed in the following directories: `/usr/local/bin' binaries. `/usr/local/share/emacs/22.1' Lisp code and support files. `/usr/local/info' Info documentation. To install files in those default directories, become the superuser and type make install Note that `make install' will overwrite `/usr/local/bin/emacs' and any Emacs Info files that might be in `/usr/local/info'. Much more verbose instructions (with many more hints and suggestions) come with the Emacs sources, in the file `INSTALL'. 7.2 How do I update Emacs to the latest version? ================================================ *Note Installing Emacs::, and follow the instructions there for installation. Most files are placed in version-specific directories. Emacs 22.1, for instance, places files in `/usr/local/share/emacs/22.1'. Upgrading should overwrite only, `/usr/local/bin/emacs' (the Emacs binary) and documentation in `/usr/local/info'. Back up these files before you upgrade, and you shouldn't have too much trouble. 7.3 What should I do if I have trouble building Emacs? ====================================================== First look in the file `etc/PROBLEMS' (where 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, see *Note Help installing Emacs::. If you cannot find a solution in the documentation, send a message to . Please don't post it to `news:gnu.emacs.help' or send e-mail to . For further guidelines, see *Note Guidelines for newsgroup postings:: and *Note Reporting bugs::. 7.4 Why does linking Emacs with -lX11 fail? =========================================== Emacs needs to be linked with the static version of the X11 library, `libX11.a'. This may be missing. On OpenWindows, you may need to use `add_services' to add the "OpenWindows Programmers" optional software category from the CD-ROM. On 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 `libcurses.a' is missing, you may need to load the "Berkeley Development Option." 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 `site.cf': #define ForceNormalLib YES 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 `liboldX.a'. 8 Finding Emacs and related packages ************************************ 8.1 Where can I get Emacs on the net (or by snail mail)? ======================================================== Look in the files `etc/DISTRIB' and `etc/FTP' for information on nearby archive sites. If you don't already have Emacs, see *Note Informational files for Emacs::, for how to get these files. *Note Installing Emacs::, for information on how to obtain and build the latest version of Emacs, and see *Note Current GNU distributions::, for a list of archive sites that make GNU software available. 8.2 How do I find a Emacs Lisp package that does XXX? ===================================================== First of all, you should check to make sure that the package isn't already available. For example, typing `M-x apropos wordstar ' lists all functions and variables containing the string `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 (*note File-name conventions::). The Lisp source to 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. The command `C-h p' (`finder-by-keyword') allows you to browse the constituent Emacs packages. For advice on how to find extra packages that are not part of Emacs, see *Note Packages that do not come with Emacs::. 8.3 Where can I get Emacs Lisp packages that don't come with Emacs? =================================================================== The Emacs Lisp List (ELL) (http://www.anc.ed.ac.uk/~stephen/emacs/ell.html), maintained by Stephen Eglen , aims to provide one compact list with links to all of the current Emacs Lisp files on the Internet. The ELL can be browsed over the web, or from Emacs with the `ell' package (http://www.anc.ed.ac.uk/~stephen/emacs/ell.el). Many authors post their packages to the Emacs sources newsgroup (news:gnu.emacs.sources). You can search the archives of this group with Google (http://groups.google.com/group/gnu.emacs.sources), or Gmane (http://dir.gmane.org/gmane.emacs.sources), for example. Several packages are stored in the Lisp area of the Emacs Wiki (http://emacswiki.org/elisp/). For a long time, the Emacs Lisp Archive provided a central repository for Emacs packages. Sadly, it has not been active for some time, although you can still access the old files at `http://www.club.cc.cmu.edu/pub/gnu/elisp-archive/' Read the file `etc/MORE.STUFF' for more information about external packages. 8.4 Where can I get other up-to-date GNU stuff? =============================================== The most up-to-date official GNU software is normally kept at `ftp://ftp.gnu.org/pub/gnu' Read the files `etc/DISTRIB' and `etc/FTP' for more information. A list of sites mirroring `ftp.gnu.org' can be found at `http://www.gnu.org/order/ftp.html' 8.5 What is the difference between Emacs and XEmacs (formerly Lucid Emacs)? =========================================================================== XEmacs is a branch version of Emacs. It was first called Lucid Emacs, and was initially derived from a prerelease version of Emacs 19. In this FAQ, we use the name "Emacs" only for the official version. Emacs and XEmacs each come with Lisp packages that are lacking in the other. The two versions have some significant differences at the Lisp programming level. Their current features are roughly comparable, though the support for some operating systems, character sets and specific packages might be quite different. Some XEmacs code has been contributed to Emacs, and we would like to use other parts, but the earlier XEmacs maintainers did not always keep track of the authors of contributed code, which makes it impossible for the FSF to get copyright papers signed for that code. (The FSF requires these papers for all the code included in the Emacs release, aside from generic C support packages that retain their separate identity and are not integrated into the code of Emacs proper.) If you want to talk about these two versions and distinguish them, please call them "Emacs" and "XEmacs." To contrast "XEmacs" with "GNU Emacs" would be misleading, since XEmacs too has its origin in the work of the GNU Project. Terms such as "Emacsen" and "(X)Emacs" are not wrong, but they are not very clear, so it is better to write "Emacs and XEmacs." 8.6 Where can I get Emacs for my PC running MS-DOS? =================================================== A pre-built binary distribution of Emacs is available from the SimTel.NET archives. This version apparently works under MS-DOS and Windows (3.X, 9X, ME, NT, and 2000) and supports long file names under Windows 9X, Windows ME, and Windows 2000. More information is available from `ftp://ftp.delorie.com/pub/djgpp/current/v2gnu/emacs.README' The binary itself is available in the files `em*.zip' in the directory `ftp://ftp.delorie.com/pub/djgpp/current/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 Eli Zaretskii and Darrel Hankerson , you will need the following: _Compiler_ DJGPP version 1.12 maint 1 or later. Djgpp 2.0 or later is recommended, since 1.x is very old an unmaintained. Djgpp 2 supports long file names on Windows 9X/ME/2K. You can get the latest release of DJGPP by retrieving all of the files in `ftp://ftp.delorie.com/pub/djgpp/current/v2*' _Unpacking program_ 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 `djdevNNN.zip' archive (where NNN is the DJGPP version number), from the URL mentioned above. *Warning!* Do *not* use the popular WinZip program to unpack the Emacs distribution! WinZip is known to corrupt some of the files by converting them to the DOS CR-LF format, it doesn't always preserve the directory structure recorded in the compressed Emacs archive, and commits other atrocities. Some of these problems could actually prevent Emacs from building successfully! _make, mv, sed, and rm_ All of these utilities are available at `ftp://ftp.delorie.com/pub/djgpp/current/v2gnu' 16-bit utilities can be found in GNUish, at `http://www.simtel.net/pub/gnuish/' (`mv' and `rm' are in the Fileutils package, `sed' and `make' are each one in a separate package named after them.) The files `INSTALL' (near its end) and `etc/PROBLEMS' in the directory of the Emacs sources 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 `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. 8.7 Where can I get Emacs for Microsoft Windows? ================================================ For information on Emacs for Windows 95 and NT, read the FAQ produced by Geoff Voelker and currently maintained by Ramprasad B , available at `http://www.gnu.org/software/emacs/windows/ntemacs.html' *Note Emacs for MS-DOS::, for Windows 3.1. A port of Emacs 20.7 for Windows CE, based on NTEmacs, is available at `http://www.rainer-keuchel.de/software.html' This port was done by Rainer Keuchel , and supports all Emacs features except async subprocesses and menus. You will need MSVC 6.0 and a Windows CE SDK to build this port. 8.8 Where can I get Emacs for my PC running OS/2? ================================================= Emacs 20.6 is ported for emx on OS/2 2.0 or 2.1, and is available at `ftp://hobbes.nmsu.edu/pub/os2/apps/editors/emacs/' and also at `http://www.dotemacs.de/os2/emacs.html' Instructions for installation, basic setup, and other useful information for OS/2 users of Emacs can be found at `http://home.snafu.de/ohei/emacs/emacs206-os2.html' 8.9 Where can I get Emacs for my Atari ST? ========================================== Roland Scha"uble reports that Emacs 18.58 running on plain TOS and MiNT is available at `ftp://atari.archive.umich.edu/Editors/Emacs-18-58/1858b-d3.zoo'. 8.10 Where can I get Emacs for my Amiga? ======================================== The files you need are available at `ftp://ftp.wustl.edu/pub/aminet/util/gnu/' David Gilbert has released a beta version of Emacs 19.25 for the Amiga. You can get the binary at `ftp://ftp.wustl.edu/pub/aminet/util/gnu/a2.0bEmacs-bin.lha' 8.11 Where can I get Emacs for NeXTSTEP? ======================================== Emacs.app is a NeXTSTEP version of Emacs 19.34 which supports colors, menus, and multiple frames. You can get it from `ftp://next-ftp.peak.org/pub/next-ftp/next/apps/emacs/Emacs_for_NeXTstep.4.20a1.NIHS.b.tar.gz' 8.12 Where can I get Emacs for my Apple computer? ================================================= Beginning with version 21.1, the Macintosh is supported in the official Emacs distribution; see the files `mac/README' and `mac/INSTALL' in the Emacs distribution for build instructions. Beginning with version 22.1, Emacs supports Mac OS X natively. 8.13 Where do I get Emacs that runs on VMS under DECwindows? ============================================================ Up-to-date information about GNU software (including Emacs) for VMS is available at `http://www.lp.se/gnu-vms/'. 8.14 Where can I get modes for Lex, Yacc/Bison, Bourne shell, csh, C++, Objective-C, Pascal, Java, and Awk? =========================================================================================================== Most of these modes are now available in standard Emacs distribution. To get additional modes, see *Note Finding a package with particular functionality::. Barry Warsaw's `cc-mode' now works for C, C++, Objective-C, and Java code. It is distributed with Emacs, but has its own homepage (http://cc-mode.sourceforge.net/). 9 Major packages and programs ***************************** 9.1 VM (View Mail) -- another mail reader within Emacs, with MIME support ========================================================================= Author Kyle Jones Latest version 7.19 Distribution `ftp://ftp.wonderworks.com/pub/vm/vm.tar.gz' Informational newsgroup `news:gnu.emacs.vm.info' Bug reports newsgroup `news:gnu.emacs.vm.bug' Or send reports to VM 7 works well with Emacs 21 and Emacs 22. Older versions of VM suitable for use with older versions of Emacs are available from the same FTP site (ftp://ftp.wonderworks.com/pub/vm/). 9.2 Supercite -- mail and news citation package within Emacs ============================================================ Author Barry Warsaw Latest version 3.54 (comes bundled with Emacs since version 20) Distribution `http://www.python.org/emacs/supercite.tar.gz' Mailing list Subscription requests to Submissions Superyank is an old version of Supercite. 9.3 Calc -- poor man's Mathematica within Emacs =============================================== Author Dave Gillespie Latest version 2.1 (part of Emacs since version 22.1) Distribution No separate distribution outside of Emacs. Older versions are available at `ftp://ftp.gnu.org/pub/gnu/calc/'. Note that Calc 2.02f needs patching to work with Emacs 21 and later. Emacs 21.1 and later comes with a package called `calculator.el'. It doesn't support all the mathematical wizardry offered by Calc, such as matrices, special functions, and statistics, but is more than adequate as a replacement for `xcalc' and similar programs. 9.4 VIPER -- `vi' emulation for Emacs ===================================== Since Emacs 19.29, the preferred `vi' emulation in Emacs is VIPER (`M-x viper-mode '), which comes with Emacs. It extends and supersedes VIP (including VIP 4.3) and provides `vi' emulation at several levels, from one that closely follows `vi' to one that departs from `vi' in several significant ways. For Emacs 19.28 and earlier, the following version of VIP is generally better than the one distributed with Emacs: Author Aamod Sane Latest version 4.3 Distribution `ftp://www.club.cc.cmu.edu/pub/gnu/elisp-archive/modes/vip-mode.tar.Z' 9.5 AUCTeX -- enhanced TeX modes with debugging facilities ========================================================== AUCTeX is a set of sophisticated major modes for TeX, LaTeX, ConTeXt, and Texinfo offering context-sensitive syntax highlighting, indentation, formatting and folding, macro completion, TeX shell functionality, and debugging. Be also sure to check out *Note RefTeX: (reftex)Introduction. Current versions of AUCTeX include the preview-latex (http://www.gnu.org/software/auctex/preview-latex) package for WYSIWYG previews of various LaTeX constructs in the Emacs source buffer. Authors Kresten Krab Thorup , Per Abrahamsen , and others. Maintainer David Kastrup Latest version 11.84 Distribution `ftp://ftp.gnu.org/pub/gnu/auctex/' Web site `http://www.gnu.org/software/auctex/' Mailing list: Subscription requests to Submissions to 9.6 BBDB -- personal Info Rolodex integrated with mail/news readers =================================================================== Maintainer Ronan Waide Latest version 2.34 Distribution `http://bbdb.sourceforge.net/' Mailing lists Subscription requests to Submissions to Release announcements: 9.7 Ispell -- spell checker in C with interface for Emacs ========================================================= Author Geoff Kuenning Latest version 3.3.02 Distribution `http://fmg-www.cs.ucla.edu/geoff/tars/ispell-3.3.02.tar.gz' Web site `http://fmg-www.cs.ucla.edu/geoff/ispell.html' This Ispell program is distinct from GNU Ispell 4.0. GNU Ispell 4.0 is no longer a supported product. 9.8 Emacs/W3 -- A World Wide Web browser inside of Emacs ======================================================== Author Bill Perry Maintainer Emacs/W3 needs a maintainer. It has lain dormant for several years. If you would like to take over the project, please contact . Latest version 4.0pre.47 Distribution `http://savannah.gnu.org/projects/w3' Mailing lists Receive announcements from Help to develop Emacs/W3 at 9.9 EDB -- Database program for Emacs; replaces forms editing modes =================================================================== Author Michael Ernst Latest version 1.21 Distribution `ftp://theory.lcs.mit.edu/pub/emacs/edb' 9.10 Mailcrypt -- PGP interface within Emacs mail and news ========================================================== Authors Patrick J. LoPresti and Jin S. Choi Maintainer Brian Warner Latest version 3.5.8 Distribution `http://dl.sourceforge.net/sourceforge/mailcrypt/mailcrypt-3.5.8.tar.gz' Web site `http://mailcrypt.sourceforge.net/' Note that a new package called PGG is bundled with Emacs starting with version 22.1. It is a modern interface to various PGP implementations, including The GNU Privacy Guard (http://www.gnupg.org/) and supports symmetric encryption. 9.11 JDE -- Integrated development environment for Java ======================================================= Author Paul Kinnucan Latest version 2.3.5 Web site `http://jdee.sunsite.dk/' Mailing lists Subscription requests to Receive announcements from 9.12 Patch -- program to apply "diffs" for updating files ========================================================= Author Larry Wall (with GNU modifications) Latest version 2.5.4 Distribution *Note Current GNU distributions::. 10 Key bindings *************** 10.1 How do I bind keys (including function keys) to commands? ============================================================== Keys can be bound to commands either interactively or in your `.emacs' file. To interactively bind keys for all modes, type `M-x global-set-key KEY CMD '. To bind a key just in the current major mode, type `M-x local-set-key KEY CMD '. *note Key Bindings: (emacs)Key Bindings, for further details. To make the process of binding keys interactively easier, use the following "trick": First bind the key interactively, then immediately type `C-x C-a C-k C-g'. Now, the command needed to bind the key is in the kill ring, and can be yanked into your `.emacs' file. If the key binding is global, no changes to the command are required. For example, (global-set-key (quote [f1]) (quote help-for-help)) can be placed directly into the `.emacs' file. If the key binding is local, the command is used in conjunction with the `add-hook' function. For example, in TeX mode, a local binding might be (add-hook 'tex-mode-hook (lambda () (local-set-key (quote [f1]) (quote help-for-help)))) * Control characters in key sequences, in the form yanked from the kill ring are given in their graphic form--i.e., is shown as `^', as a set of spaces (usually 8), etc. You may want to convert these into their vector or string forms. * If a prefix key of the character sequence to be bound is already bound as a complete key, then you must unbind it before the new binding. For example, if `ESC {' is previously bound: (global-unset-key [?\e ?{]) ;; or (local-unset-key [?\e ?{]) * Aside from commands and "lambda lists," a vector or string also can be bound to a key and thus treated as a macro. For example: (global-set-key [f10] [?\C-x?\e?\e?\C-a?\C-k?\C-g]) ;; or (global-set-key [f10] "\C-x\e\e\C-a\C-k\C-g") 10.2 Why does Emacs say `Key sequence XXX uses invalid prefix characters'? ========================================================================== Usually, one of two things has happened. In one case, the control character in the key sequence has been misspecified (e.g. `C-f' used instead of `\C-f' within a Lisp expression). In the other case, a "prefix key" in the keystroke sequence you were trying to bind was already bound as a "complete key". Historically, the `ESC [' prefix was usually the problem, in which case you should evaluate either of these forms before attempting to bind the key sequence: (global-unset-key [?\e ?[]) ;; or (global-unset-key "\e[") 10.3 Why doesn't this [terminal or window-system setup] code work in my `.emacs' file, but it works just fine after Emacs starts up? ==================================================================================================================================== During startup, Emacs initializes itself according to a given code/file order. If some of the code executed in your `.emacs' file needs to be postponed until the initial terminal or window-system setup code has been executed but is not, then you will experience this problem (this code/file execution order is not enforced after startup). To postpone the execution of Emacs Lisp code until after terminal or window-system setup, treat the code as a "lambda list" and set the value of either the `term-setup-hook' or `window-setup-hook' variable to this lambda function. For example, (add-hook 'term-setup-hook (lambda () (when (string-match "\\`vt220" (or (getenv "TERM") "")) ;; Make vt220's "Do" key behave like M-x: (global-set-key [do] 'execute-extended-command)))) For information on what Emacs does every time it is started, see the `lisp/startup.el' file. 10.4 How do I use function keys under X? ======================================== With Emacs 19, functions keys under X are bound like any other key. *Note Binding keys to commands::, for details. 10.5 How do I tell what characters or symbols my function or arrow keys emit? ============================================================================= Type `C-h c' then the function or arrow keys. The command will return either a function key symbol or character sequence (see the Emacs on-line documentation for an explanation). This works for other keys as well. 10.6 How do I set the X key "translations" for Emacs? ===================================================== Emacs is not written using the Xt library by default, so there are no "translations" to be set. (We aren't sure how to set such translations if you do build Emacs with Xt; please let us know if you've done this!) The only way to affect the behavior of keys within Emacs is through `xmodmap' (outside Emacs) or `define-key' (inside Emacs). The `define-key' command should be used in conjunction with the `function-key-map' map. For instance, (define-key function-key-map [M-] [?\M-\t]) defines the `M-' key sequence. 10.7 How do I handle `C-s' and `C-q' being used for flow control? ================================================================= `C-s' and `C-q' are used in the XON/XOFF flow control protocol. This messes things up when you're using Emacs over a serial line, because Emacs binds these keys to commands by default. Because Emacs won't honor them as flow control characters, too many of these characters are not passed on and overwhelm output buffers. Sometimes, intermediate software using XON/XOFF flow control will prevent Emacs from ever seeing `C-s' and `C-q'. Possible solutions: * Disable the use of `C-s' and `C-q' for flow control. You need to determine the cause of the flow control. - your terminal Your terminal may use XON/XOFF flow control to have time to display all the characters it receives. For example, VT series terminals do this. It may be possible to turn this off from a setup menu. For example, on a VT220 you may select "No XOFF" in the setup menu. This is also true for some terminal emulation programs on PCs. When you turn off flow control at the terminal, you will also need to turn it off at the other end, which might be at the computer you are logged in to or at some terminal server in between. If you turn off flow control, characters may be lost; using a printer connected to the terminal may fail. You may be able to get around this problem by modifying the `termcap' entry for your terminal to include extra NUL padding characters. - a modem If you are using a dialup connection, the modems may be using XON/XOFF flow control. It's not clear how to get around this. - a router or terminal server Some network box between the terminal and your computer may be using XON/XOFF flow control. It may be possible to make it use some other kind of flow control. You will probably have to ask your local network experts for help with this. - `tty' and/or `pty' devices If your connection to Emacs goes through multiple `tty' and/or `pty' devices, they may be using XON/XOFF flow control even when it is not necessary. Eirik Fuller writes: Some versions of `rlogin' (and possibly `telnet') do not pass flow control characters to the remote system to which they connect. On such systems, Emacs on the remote system cannot disable flow control on the local system. Sometimes `rlogin -8' will avoid this problem. One way to cure this is to disable flow control on the local host (the one running `rlogin', not the one running `rlogind') using the `stty' command, before starting the `rlogin' process. On many systems, `stty start u stop u' will do this. Some versions of `tcsh' will prevent even this from working. One way around this is to start another shell before starting rlogin, and issue the `stty' command to disable flow control from that shell. Use `stty -ixon' instead of `stty start u stop u' on some systems. * Make Emacs speak the XON/XOFF flow control protocol. You can make Emacs treat `C-s' and `C-q' as flow control characters by evaluating the form (enable-flow-control) to unconditionally enable flow control or (enable-flow-control-on "vt100" "h19") (using your terminal names instead of `vt100' or `h19') to enable selectively. These commands will automatically swap `C-s' and `C-q' to `C-\' and `C-^'. Variables can be used to change the default swap keys (`flow-control-c-s-replacement' and `flow-control-c-q-replacement'). If you are fixing this for yourself, simply put the form in your `.emacs' file. If you are fixing this for your entire site, the best place to put it is in the `site-lisp/site-start.el' file. (Here `site-lisp' is actually a subdirectory of your Emacs installation directory, typically `/usr/local/share/emacs'.) Putting this form in `site-lisp/default.el' has the problem that if the user's `.emacs' file has an error, this will prevent `default.el' from being loaded and Emacs may be unusable for the user, even for correcting their `.emacs' file (unless they're smart enough to move it to another name). `enable-flow-control' can be invoked interactively as well: `M-x enable-flow-control '. For further discussion of this issue, read the file `etc/PROBLEMS' (in the Emacs source directory when you unpack the Emacs distribution). 10.8 How do I bind `C-s' and `C-q' (or any key) if these keys are filtered out? =============================================================================== To bind `C-s' and `C-q', use either `enable-flow-control' or `enable-flow-control-on'. *Note Handling C-s and C-q with flow control::, for usage and implementation details. To bind other keys, use `keyboard-translate'. *Note Swapping keys::, for usage details. To do this for an entire site, you should swap the keys in `site-lisp/site-start.el'. *Note Handling C-s and C-q with flow control::, for an explanation of why `site-lisp/default.el' should not be used. * If you do this for an entire site, the users will be confused by the disparity between what the documentation says and how Emacs actually behaves. 10.9 Why does the key in