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Path: senator-bedfellow.mit.edu!enterpoop.mit.edu!eru.mt.luth.se!kth.se!sunic!mcsun!uknet!doc.ic.ac.uk!agate!dog.ee.lbl.gov!network.ucsd.edu!swrinde!cs.utexas.edu!newsfeed.rice.edu!rice!sbyrnes From: sbyrnes@rice.edu (Steven Byrnes) Newsgroups: gnu.emacs.help,comp.emacs,news.answers,comp.answers Subject: GNU Emacs FAQ (4/5, 125-151): Keybindings/Output Summary: READ BEFORE POSTING. A regularly posted list of answers to frequently asked questions (FAQs) about GNU Emacs and many Emacs Lisp programs. Contains pointers to other resources. Follow "References:" link for more metainfo. Keywords: gnu emacs faq answers frequently asked questions periodic Message-ID: <GNU-Emacs-FAQ-4.1993.05.04.025218@rice.edu> Date: 4 May 93 02:52:18 GMT Expires: Sat, 3 Jul 1993 02:52:18 GMT References: <GNU-Emacs-FAQ-0.1993.05.04.025218@rice.edu> Sender: news@rice.edu (News) Reply-To: gnu-emacs-faq-maintainers@bigbird.bu.edu Followup-To: poster Organization: GNU's Not UNIX Lines: 1006 Approved: news-answers-request@mit.edu Supersedes: <GNU-Emacs-FAQ-4.1993.01.05.171933@rice.edu> Originator: sbyrnes@is.rice.edu Xref: senator-bedfellow.mit.edu gnu.emacs.help:10209 comp.emacs:17191 news.answers:8182 comp.answers:624 Archive-Name: GNU-Emacs-FAQ/part4 Last-Modified: Sat, 6 Mar 1993 21:13:32 GMT Last-Posted: Tue, 4 May 1993 02:52:18 GMT GNU Emacs FAQ: Keybindings/Output If you are viewing this text in a GNU Emacs Buffer, you can type "M-2 C-x $" to get an overview of just the questions. Then, when you want to look at the text of the answers, just type "C-x $". To search for a question numbered XXX, type "M-C-s ^XXX:", followed by a C-r if that doesn't work, then type ESC to end the search. A `+' in the 78th column means something was inserted on the line. A `-' means something was deleted and a `!' means some combination of insertions and deletions occurred. Full instructions for getting the latest FAQ are in question 22. Also see the `Introduction to news.answers' posting in the `news.answers' newsgroup, or send e-mail to `mail-server@rtfm.mit.edu' with `help' on a body line, or use FTP, WAIS, or Prospero to rtfm.mit.edu. Changing Key Bindings and Handling Key Binding Problems 125: How do I bind keys (including function keys) to commands? 1. Find out what character sequence is generated by the keystroke sequence you wish to bind to a command. See question 129 for how to do this. Keep in mind that the character sequences generated by a keystroke sequence varies from one terminal to another. You may also get different results depending on what type of machine you are running on (see question 128). For example, these keystrokes may generate these character sequences: F1 ---> ESC [ 2 2 4 z Shift-R10 ---> ESC O t L7 ---> ESC [ 3 1 ~ Remove ---> C-@ 2. Figure out what the Emacs Lisp syntax is for this character sequence. Inside an Emacs Lisp string, RET, LFD, DEL, ESC, SPC, and TAB are specified with `\r', `\n', `\C-?', `\e', ` ', and `\t'. C-x is specified by `\C-x'. M-x is specified the same was as "ESC x". (Control characters may also be specified as themselves, but I don't recommend it.) An Emacs Lisp string begins and ends with the double quote character, `"'. Here are some examples: ESC [ D ---> "\e[D" ESC [ 2 2 7 z ---> "\e[227z" ESC [ 1 8 ~ ---> "\e[18~" C-M-r ---> "\e\C-r" 3. If some prefix of the character sequence is already bound, you must unbind it by binding it to `nil'. For example: (global-set-key "\e[" nil) 4. Pick a command to bind your key sequence to. A command can be a "symbol" with a function definition, or a "lambda list", or a string (which is treated as a macro). For example: (global-set-key "\e[D" 'backward-char) (global-set-key "\e[227~" "\exgoto-line\r") ; macro See `Key Bindings' and `Rebinding' in the online manual. In Emacs 19 (including Lucid Emacs), you can bind function key F24 like this: (global-set-key 'f24 'some-command) 126: Why does Emacs say `Key sequence XXX uses invalid prefix characters'? A prefix of the character sequence you were trying to bind was already bound. Usually, the sequence is "ESC [", in which case you should evaluate this form first: (define-key esc-map "[" nil) NOTE: By default, "ESC [" is bound to backward-paragraph, and if you do this you will lose this key binding. For most people, this is not a problem. See question 125. 127: Why doesn't this [terminal or window-system setup] code work in my .emacs file, but it works just fine after Emacs starts up? This is because you're trying to do something in your .emacs file that needs to be postponed until after the terminal/window-system setup code is loaded. This is a result of the order in which things are done during the startup of Emacs. For more details see question 135. In order to postpone the execution of Emacs Lisp code until after the terminal/window-system setup, set the value of the variable term-setup-hook or window-setup-hook to be a function which does what you want. See etc/OPTIONS for a complete explanation of what Emacs does every time it is started. Here is a simple example of how to set term-setup-hook: (setq term-setup-hook (function (lambda () (cond ((string-match "\\`vt220" (or (getenv "TERM") "")) ;; Make vt220's "Do" key behave like M-x: (define-key CSI-map "29~" 'execute-extended-command)) )))) 128: How do I use function keys under X Windows? This depends on whether you are running Emacs inside a terminal emulator window, or whether you are allowing Emacs to create its own X window. You can tell which you are doing by noticing whether Emacs creates a new window when you start it. If you are running Emacs inside a terminal emulator window, then it behaves exactly as it does on any other tty. In this case, for function keys to be useful, they must generate character sequences that are sent to the programs running inside the window as input. The `xterm' program has two different sets of character sequences that it generates when function keys are pressed, depending on the sunFunctionKeys X resource and the -sf and +sf command line options. (To find out what these key sequences are, see question 129.) In addition, with xterm, you can override what key sequence a specific function key (or any other key) will generate with the `translations' resource. This, for example: XTerm.VT100.Translations: #override \ <KeyPress>F1: string(0x1b) string("[xyzzy") makes the function key F1 generate the character sequence "ESC [xyzzy". On the other hand, if Emacs is managing its own X window, the following description applies. Emacs receives `KeyPress' events from the X server when a key is pressed while the keyboard focus is in its window. The KeyPress event contains an X "keysym" code, which is simply an arbitrary number corresponding to the name of the keysym, and information on which "modifiers" such as `control' and `shift' are active. For example, the `Tab' keysym is 0xff09. (Generally, a key on the keyboard will generate a keysym whose name is the same as the label on the key, ie. the `Tab' key will normally generate the `Tab' keysym. This can be changed with the xmodmap program.) Emacs recognizes all the keysyms that correspond to standard ASCII characters and internally uses the ASCII character instead. (WARNING: I am about to describe a gross, disgusting hack to you, have your barf bag ready.) When Emacs receives the X keysym of one of the arrow keys, it behaves the same as if it had received a letter key with the control modifier down as follows (this is hard-coded): Up becomes C-p Down becomes C-n Right becomes C-f Left becomes C-b The way Emacs treats other keysyms depends on what kind of machine it was compiled on. The type of the display machine is irrelevant! Function keys are mapped internally to escape sequences, while other keys are completely ignored. 1. If compiled on a Sun, Emacs recognizes these X keysyms that are normally on a Sun keyboard: F1 through F9 L1 through L10 (same as F11 through F20) R1 through R15 (same as F21 through F35) (The keys labelled R8, R10, R12, and R14 usually are mapped to the X keysyms Up, Left, Right, and Down.) Break (the `Alternate' key is given this keysym) These keys work like Sun function keys. When Emacs recieves the keysym, it will internally use character sequences that look like "ESC [ ### z", where ### is replaced by a number. The character sequences are identical to those generated by Sun's keyboard under SunView. Any function key not listed above generates "ESC [ - 1 z". In order to use these key sequences, they should be bound to commands using the standard key binding methods, just as if Emacs were running on a regular terminal. WARNING: F11 and L1 are the same keysym in X, as are F12 and L2, etc. {Yes, this is stupid. Complain to the X consortium.} 2. If not compiled on a Sun, the function keys will appear to Emacs in a way remarkably similar to the keys of a DEC LK201 keyboard (used on some VT series terminals). These X keysyms will be recognized: F1 through F20 Help (treated same as F15) Menu (treated same as F16, is the LK201 `Do' key) Find Insert (LK201 `Insert Here' key) Select Prior (LK201 `Prev Screen' key *** ONLY IN 18.58 AND LATER ***) Next (LK201 `Next Screen' key *** ONLY IN 18.58 AND LATER ***) And finally, the LK201 key labelled `Remove' (or `Delete') is often mapped to the Delete keysym which generates the DEL character (C-?) instead of the key sequence given by the LK201 `Remove' key. It may also be mapped to some other keysym, such as `_Remove', in which case you can't use it from within Emacs at all. Each function key will be internally converted to a character sequence that looks like "ESC [ ## ~", where ## is replaced by a number. The character sequences are identical to those generated by a LK201 keyboard. Any function key not listed above generates "ESC [ - 1 ~". For the complete list of the numbers which are generated by the function keys, look in the file src/x11term.c at the definitions of the function stringFuncVal. If you are running Emacs on a Sun machine, even if your X display is running on a non-Sun machine (eg., an X terminal), you get the setup described above for Suns. The determining factor is what type of machine Emacs is running (was compiled) on, not what type of machine your X display is on. If you have function keys not listed above on your keyboard, you can use `xmodmap' to change their keysym assignments to get keys that Emacs will recognize, but that may screw up other programs. X resources are not used by Emacs to affect the key sequences generated. In particular, there are no X key "translations" for Emacs. If you have function keys not listed above and you don't want to use xmodmap to change their names, you might want to make a modification to your Emacs. Johan Vromans <jv@mh.nl> has made available a patch for Emacs that adds the x-rebind-key function of Epoch to Emacs 18.58. This allows another layer of key rebinding before Emacs even sees the keys, and in this layer you can rebind all of the keys and modifier combinations as well. Anonymous FTP: /ftp.eu.net:gnu/emacs/FP-Xfun.Z /ftp.urc.tue.nl:pub/tex/emacs/FP-Xfun Johan Vromans explains what this buys for you: After implementing this, all keyboard keys can be configured to send user definable sequences, eg., (x-rebind-key "KP_F1" 0 "\033OP") This will have the keypad key PF1 send the sequence "ESC O P", just like an ordinary VT series terminal. 129: How do I tell what characters my function or arrow keys emit? Use this function by Randal L. Schwartz <merlyn@iwarp.intel.com>: (defun see-chars () "Displays characters typed, terminated by a 3-second timeout." (interactive) (let ((chars "") (inhibit-quit t)) (message "Enter characters, terminated by 3-second timeout.") (while (not (sit-for 3)) (setq chars (concat chars (list (read-char))) quit-flag nil)) ; quit-flag maybe set by C-g (message "Characters entered: %s" (key-description chars)))) Alternatively, use the "C-h l" view-lossage command, which will display the last 100 characters Emacs has seen in its input stream. Kevin Gallagher <kgallagh@digi.lonestar.org> suggests typing some unique string like "wxyz", typing the key in question, then typing "C-h l". The characters that appear between "wxyz" and "C-h l" were generated by the key. 130: How do I set the X key "translations" for Emacs? Sorry, you can't; there are no "translations" to be set. Emacs is not written using the Xt library. The only way to affect the behavior of keys within Emacs is through `xmodmap' (outside Emacs) or `define-key' (inside Emacs). 131: 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 screws up Emacs because it binds these characters to commands. Also, by default Emacs will not honor them as flow control characters and may 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 what is 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. I don't know 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 <eirik@theory.tn.cornell.edu> 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 this form: (set-input-mode nil t) 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 unclear. I don't know if this has any effect when used in lisp/site-init.el when building Emacs; I've never tried that. {Can someone tell me whether it works?} Putting things in users' .emacs files has a number of problems. Putting this form in lisp/default.el has the problem that if the user's .emacs file has an error, this will prevent lisp/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). A possible solution is to initially disable C-s and C-q by setting keyboard-translate-table in lisp/site-init.el, either with swap-keys (see question 136) or with the following form: ;; by Roger Crew <crew@cs.stanford.edu>: (setq keyboard-translate-table "\C-@\C-a\C-b\C-c\C-d\C-e\C-f\C-g\C-h\C-i\C-j\C-k\C-l\C-m\C-n\C-o\C-p\C-^\C-r\C-\\\C-t\C-u\C-v\C-w\C-x\C-y\C-z\C-[\C-s\C-]\C-q\C-_") This will at least prevent Emacs from being confused by the flow control characters, even if lisp/default.el cannot be loaded. Then, in lisp/default.el, enable XON/XOFF flow control with set-input-mode. For further discussion of this issue, read the file PROBLEMS in the Emacs distribution. 132: How do I use commands bound to C-s and C-q (or any key) if these keys are filtered out? I suggest swapping C-s with C-\ and C-q with C-^: (swap-keys ?\C-s ?\C-\\) (swap-keys ?\C-q ?\C-^) See question 136 for the implementation of swap-keys. This method has the advantage that it simultaneously swaps the characters everywhere throughout Emacs, while just switching the keybindings will miss important places where the character codes are stored (eg., the search-repeat-char variable, major mode keymaps, etc.). To do this for an entire site, you may want to swap the keys in lisp/default.el. If only some of your users are connecting through XON/XOFF flow-controlled connections, you will want to do this conditionally. I suggest pre-swapping them in lisp/site-init.el when Emacs is built, and then in lisp/default.el, if it is determined to be safe, they can be reenabled (being careful not to screw up any other key mappings users might have established using keyboard-translate-table). See question 131 for an easy way to pre-swap these keys. WARNING: 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. 133: Why does the `BackSpace' key invoke help? The BackSpace key (on every keyboard I've used) generates ASCII code 8. C-h sends the same code. In Emacs by default C-h invokes help-command. This is intended to be easy to remember since the first letter of "help" is "h". The easiest solution to this problem is to use C-h (and BackSpace) for help and DEL (the Delete key) for deleting the previous character. For many people this solution may be problematic: * They normally use BackSpace outside of Emacs for deleting the previous character typed. This can be solved by making DEL be the command for deleting the previous character outside of Emacs. This command will do this on many Unix systems: stty erase '^?' * The person may prefer using the BackSpace key for deleting the previous character because it is more conveniently located on their keyboard or because they don't even have a separate Delete key. In this case, the BackSpace key should be made to behave like Delete. There are several methods. * Under X Windows, the easiest solution is to change the BackSpace key into a Delete key like this: xmodmap -e "keysym BackSpace = Delete" * Some terminals (eg., VT3## terminals) allow the character generated by the BackSpace key to be changed from a setup menu. * You may be able to get a keyboard that is completely programmable. * Under X or on a dumb terminal, it is possible to swap the BackSpace and Delete keys inside Emacs: (swap-keys ?\C-h ?\C-?) See question 136 for the implementation of swap-keys. * Another approach is to switch keybindings and put help on "C-x h" instead: (global-set-key "\C-h" 'delete-backward-char) (global-set-key "\C-xh" 'help-command) ; override mark-whole-buffer Other popular key bindings for help are M-? and "C-x ?". WARNING: Don't try to bind DEL to help-command, because there are many modes that have local bindings of DEL that will interfere. 134: Why doesn't Emacs look at the stty settings for Backspace vs. Delete? Good question! 135: Why don't the arrow keys work? When Emacs starts up, it doesn't know anything about arrow keys at all (except when running under X, see question 128). During the process of starting up, Emacs will load a terminal-specific initialization file for your terminal type (as determined by the environment variable TERM), if one exists. This file has the responsibility for enabling the arrow keys. There are several things that can go wrong: 1. There is no initialization file for your terminal. You can determine this by looking in the lisp/term directory. If your terminal type (as determined by the TERM environment variable) is xxx-yy-z, then the first of these files in the lisp/term directory will be loaded as the terminal-specific initialization file: xxx-yy-z.el, xxx-yy.el, or xxx.el. There are two major cases of this problem: * Your terminal type is very similar to one that has an init file. In this case, there are several techniques suggested by Colin Jensen <cjensen@ampex.com>, Ben Liblit <Liblit@cs.psu.edu>, and Marc Auslander <marc@watson.ibm.com>: A. Add a symbolic link in lisp/term for your terminal type that points to the similar type. For example, you could make VT102 terminals work with this command: ln -s vt100.el vt102.el This fixes things for everyone on the system who uses the terminal type. B. If you can't do the solution in part A, you can add code to your term-setup-hook that loads the correct file like this: (setq term-setup-hook (function (lambda () (cond ((equal "vt102" (or (getenv "TERM") "")) (load (concat term-file-prefix "vt100"))) (;; Code for other terminal types goes here ... ))))) C. If you use `tset' to set your TERM environment variable when you login, you can use the `-m' switch to tell tset to use a terminal type known by Emacs instead of another similar one. For example, specifying this: tset ... -m 'dec-vt220:vt220' ... will make tset say you are on a `vt220' instead of a `dec-vt220'. D. Interactively, you can type "M-x load-library RET term/vt100" to load the terminal-specific initialization files for VT100 terminals. * Your terminal type is not similar to one that has an init file. One can be made for your terminal, or you can just add code to your own .emacs to handle this problem for yourself. For example, if your terminal's arrow keys send these character sequences: Up: ESC [ A Down: ESC [ B Right: ESC [ C Left: ESC [ D then you can bind these keys to the appropriate commands with code in your .emacs like this: (setq term-setup-hook (function (lambda () (cond ((string-match "\\`xyzzy" (or (getenv "TERM") "")) ;; First, must unmap the binding for left bracket (or (keymapp (lookup-key global-map "\e\[")) (define-key global-map "\e\[" nil)) ;; Enable terminal type xyzzy's arrow keys: (define-key global-map "\e\[A" 'previous-line) (define-key global-map "\e\[B" 'next-line) (define-key global-map "\e\[C" 'forward-char) (define-key global-map "\e\[D" 'backward-char)) ((string-match "\\`abcde" (or (getenv "TERM") "")) ;; Do something different for terminal type abcde ;; ..... ))))) NOTE: You may have to restart Emacs to get changes to take effect. NOTE: Your arrow keys may send sequences beginning with "ESC O" when Emacs is running, even if they send sequences beginning with "ESC [" at all other times. This is because Emacs uses any command there may be in your terminal's termcap entry for putting the terminal into "Application Keypad Mode". Just map these sequences the same way as above. The next two cases are problems even if there is a initialization file for your terminal type. 2. The initialization file for your terminal doesn't bind arrow keys. If your terminal type is `xterm', you will have to bind the arrow keys as in part 1 above, since the xterm.el file doesn't do anything useful. There may be other terminal types with the same problem. 3. Your terminal's arrow keys send individual control characters. For example, the arrow keys on an ADM-3 send C-h, C-j, C-k, and C-l. There is not much Emacs can do in this situation, since all the control characters except for C-^ and C-\ are already used as Emacs commands. It may be possible to convince the terminal to send something else when you press the arrow keys; it is worth investigating. You have to make the hard choices of how to rebind keys to commands to make things work the way you want. Another alternative is to start learning the standard Emacs keybindings for moving point around: C-b, C-f, C-p, and C-n. Personally, I no longer use the arrow keys when editing because I have switched keyboards so many times. 4. Your terminal's arrow keys send sequences beginning with "ESC [". Due to an extremely poor design decision (ie., these sequences are ANSI standard), none of the the terminal-specific initialization files that are distributed with Emacs will bind these character sequences to the appropriate commands by default. (This also applies to any other function keys which generate character sequences starting with "ESC [".) This is because it was deemed far more important to preserve the binding of M-[ to the backward-paragraph command. It appears that this will change in Emacs 19. Some of the terminal-specific initialization files that come with Emacs provide a command enable-arrow-keys that will fix this problem. To get this automatically invoked, put this in your .emacs: (setq term-setup-hook (function (lambda () (if (fboundp 'enable-arrow-keys) (enable-arrow-keys))))) We put this in our lisp/default.el file, so users don't have to worry about it: ;; don't override a user's term-setup-hook (or term-setup-hook (setq term-setup-hook (function (lambda () (and (fboundp 'enable-arrow-keys) ;; don't override a user key mapping (eq 'backward-paragraph (lookup-key esc-map "[")) (enable-arrow-keys)))))) If your terminal type is `sun', you should put this in your .emacs instead (or in addition to the above): (setq sun-esc-bracket t) It is possible that the terminal-specific initialization file for your terminal type was written locally and does not follow the rule mentioned above. In this case you may need to inspect it to find out how to enable the arrow keys. (Actually, if it was written locally, it probably enables the arrow keys by default.) 136: How do I "swap" two keys? When Emacs receives a character, you can make Emacs behave as though it received another character by setting the value of keyboard-translate-table. The following Emacs Lisp will do this for you, allowing you to "swap" keys. After arranging for this Lisp to be evaluated by Emacs, you can evaluate `(swap-keys ?A ?B)' to swap A and B. (defun swap-keys (key1 key2) "Swap keys KEY1 and KEY2 using map-key." (map-key key1 key2) (map-key key2 key1)) (defun map-key (from to) "Make key FROM behave as though key TO was typed instead." (setq keyboard-translate-table (concat keyboard-translate-table (let* ((i (length keyboard-translate-table)) (j from) (k i) (str (make-string (max 0 (- j (1- i))) ?X))) (while (<= k j) (aset str (- k i) k) (setq k (1+ k))) str))) (aset keyboard-translate-table from to) (let ((i (1- (length keyboard-translate-table)))) (while (and (>= i 0) (eq (aref keyboard-translate-table i) i)) (setq i (1- i))) (setq keyboard-translate-table (if (eq i -1) nil (substring keyboard-translate-table 0 (1+ i)))))) NOTE: You must evaluate the definition of these functions before calling them! For example, list the function definitions before their use in your .emacs file. NOTE: These functions take two numbers as arguments. The example above, `(swap-keys ?A ?B)' is actually `(swap-keys 65 66)', because `?A' is merely notation for 65, the ASCII value of `A'. NOTE: These functions only work for single characters. You cannot swap two multi-character sequences. 137: How do I produce C-XXX with my keyboard? For C-@ and C-^, often you can just type Control-2 and Control-6. For C-_, you may have to hold down the shift key, typing Control-Shift-Hyphen. C-@ can often be generated by typing Control-Space. C-@ is often called the NUL character, and has ASCII value 0. C-_ can often be generated by typing Control-7 or Control-/. C-? (aka DEL) may be generated by typing Shift-BackSpace or Control-BackSpace or a key labelled Delete or Del. Try Control with all of the digits on your keyboard to see what gets generated. 138: What if I don't have a Meta key? Instead of typing M-a, you can type "ESC a" instead. In fact, Emacs converts M-a internally into "ESC a" anyway (depending on the value of meta-prefix-char). 139: What if I don't have an Escape key? Type C-[ instead. This should send ASCII code 27 just like an Escape key would. Try also C-;. 140: How do I type DEL on PC terminal emulators? Some IBM PC compatibles do not have a key labeled `Del' or `Delete' {is this true?}. Those that do generally have it in an inconvenient location. (Also, in some terminal emulators, the `Del' key does not transmit DEL.) The result is the standard "BackSpace invoking help" problem (see question 133). The usual solution, suggested by Michael Covington <mcovingt@aisun1.ai.uga.edu>, is to somehow tell the terminal emulator program that BackSpace should transmit DEL. Read the program's manual. Shift-BackSpace or Control-BackSpace may send DEL. The `Del' key may only send DEL if the NumLock key hasn't been pressed. 141: Can I make my `Compose Character' key behave like a Meta key? On a dumb terminal such as a VT220, no. It is rumored that certain VT220 clones could have their Compose key configured this way. If you're using X, you might be able to do this with the `xmodmap' program (this is what I do). 142: How do I bind a combination of modifier key and function key? Unless you're using Emacs under emacstool (or xvetool?), have a working version of x-rebind-key (see question 128), or are using Emacs 19 (Lucid Emacs), you can't do this with Emacs alone. If you are using emacstool, Emacs sees different character sequences for the combination of a modifier and a function key from what it sees for the function key alone. See etc/emacstool.1 for more information. Since Emacs sees different character sequences, you can bind these different sequences to different commands. If you are running Emacs inside a terminal emulator window like xterm, you can modify its translation tables to make it generate different character sequences for the combination of a modifier and a function key. For example, this X resource setting: XTerm.VT100.Translations: #override \ Shift<KeyPress>F1: string(0x1b) string("[xyzzy") makes Shift-F1 generate the character sequence "ESC [ xyzzy". You can bind these character sequences in Emacs as normal. Nick Ruprecht <ruprecht@informatik.uni-freiburg.de> has written an extensive X translation mapping for xterm that does this. {Does this have an FTP site?} If you have x-rebind-key, you can have any arbitrary combination of modifiers with a key replaced by any sequence of "normal" characters. For example, this makes Shift-Return behave as though you had typed "C-x C-e" (example from Jerry Graves): (x-rebind-key "Return" 'shift "\C-x\C-e") In Emacs 19 (Lucid Emacs), you can bind Meta-Left-Arrow like this (example from Jamie Zawinski): (global-set-key '(meta left) 'backward-word) With the last two methods, use `xmodmap' and `xev' to discover the keysym and modifier names. 143: Why doesn't my Meta key work in an xterm window? Try all of these methods before asking for further help: * You may have big problems using `mwm' as your window manager. {Does anyone know a good generic solution to allow the use of the Meta key in Emacs with mwm?} * For X11R4: Make sure it really is a Meta key. Use `xev' to find out what keysym your Meta key generates. It should be either Meta_L or Meta_R. If it isn't, use xmodmap to fix the situation. * Make sure the pty the xterm is using is passing 8 bit characters. `stty -a' (or `stty everything') should show `cs8' somewhere. If it shows `cs7' instead, use `stty cs8 -istrip' (or `stty pass8') to fix it. * If there is an rlogin connection between the xterm and the Emacs, the `-8' argument may need to be given to rlogin to make it pass all 8 bits of every character. * If the Emacs is running under Ultrix, it is reported that evaluating (set-input-mode t nil) helps. * If all else fails, you can make xterm generate "ESC W" when you type M-W, which is the same conversion Emacs would make if it got the M-W anyway. In X11R4, the following resource specification will do this: XTerm.VT100.EightBitInput: false (This changes the behavior of the insert-eight-bit action.) With older xterms, you can specify this behavior with a translation: XTerm.VT100.Translations: #override \ Meta<KeyPress>: string(0x1b) insert() You might have to replace `Meta' with `Alt'. 144: Why doesn't my ExtendChar key work as a Meta key under HP-UX 8.0? This is a result of an internationalization extension in X11R4 and the fact that HP is now using this extension. Emacs assumes that XLookupString returns the same result regardless of the Meta key state which is no longer necessarily true. Until Emacs is fixed, the temporary kludge is to run this command after each time the X server is started but preferably before any xterm clients are: xmodmap -e 'remove mod1 = Mode_switch' NOTE: This will disable the use of the extra keysyms systemwide, which may be undesirable if you actually intend to use them. 145: Where can I get key bindings to make Emacs emulate WordStar? There is a package `wordstar' by Jim Frost <jimf@saber.com> and `ws-mode.el' by Juergen Nickelsen <nickel@cs.tu-berlin.de>. Check in the Emacs Lisp Archive (see question 89). 146: Where can I get an XEDIT emulator for Emacs? This question comes up once every couple of months. I have never seen a positive reply, so I presume no one has ever written one. Using Emacs with Alternate Character Sets 147: How do I make Emacs display 8-bit characters? There is a patch called the `8-bit ctl-arrow patch' that allows Emacs to display characters with codes from 128 to 255. {The original appears to have been by Kenneth Cline <cline@proof.ergo.cs.cmu.edu>.} Partially based on Johan Widen's earlier work, Johan Vromans <jv@mh.nl> has updated this patch for Emacs 18.58 along with some other 8-bit improvements. Anonymous FTP: /ftp.eu.net:gnu/emacs/FP-EightBit.Z /ftp.urc.tue.nl:/pub/tex/emacs/FP-EightBit /cs.purdue.edu:pub/ygz/cemacs.tar.Z:cemacs/8bit-patch-18.57 /sics.se:archive/emacs-18.55-8bit-diff /laas.laas.fr:pub/emacs/patch-8bit-18.55 /laas.laas.fr:pub/emacs/patch-8bit-18.57 Via e-mail: To: mail-server@sics.se body: send emacs-18.55-8bit-diff Anders Edenbrandt <anderse@dna.lth.se> has produced a more comprehensive patch for Emacs 18.59 that allows for 8-bit input and output. Anonymous FTP: /ftp.efd.lth.se:pub/gnu/emacs_8-bit.patch In the words of the author: With these patches, Emacs becomes fully 8-bit operational. There is support for displaying 8-bit characters, as well as for entering such characters from the keyboard. In addition, upcase/lowcase tranlatsion is supported, accented characters are recognized as "letters" (important when doing 'forward-word', for example), and text with 8-bit characters can be sorted correctly. A Meta-shift key can still be used, provided that you run in an environment where it is possible to distinguish between a character entered using the Meta-shift key and one entered directly. The diffs include patches to make this work under SunView (with emacstool) as well as under X. If you can't use a Meta-shift key, you have to enter Meta-commands with the ESC-prefix. The most comprehensive patches for 8-bit output are by Howard Gayle (originally for Emacs 18.55. These patches allow displaying any arbitrary string for a given 8-bit character (except TAB and C-j). Also supported is defining the sorting order and the uppercase and lowercase translations. It is reported that the 8-bit character support in Emacs 19 is largely based on these patches. Thomas Bellman <Bellman@lysator.liu.se> has updated these patches for Emacs 18.59. Anonymous FTP: /sics.se:archive/emacs-gayle.tar.Z (patches for 18.55) /ftp.lysator.liu.se:pub/emacs/gayle-18.58.diff.tar.Z (patches) /ftp.lysator.liu.se:pub/emacs/emacs-18.59-gayle.tar.Z (patched Emacs) Epoch's 8-bit character support is based on Anders Edenbrandt's patches. Lucid Emacs has the ctl-arrow patch installed. Nemacs displays 8-bit characters, and it may be useful for displaying the 8-bit ISO-8859 alphabet, but I don't know for sure (see question 149). 148: How do I input 8-bit characters? Minor modes for ISO Latin-1 that allow one to easily input this character set have been written by several people. Such modes have been written by Matthieu Herrb <matthieu@laas.fr> (laas.laas.fr:pub/emacs/iso-latin-1.el), Johan Vromans <jv@mh.nl> {FTP site??}, and Marc Shapiro <shapiro@sor.inria.fr> {FTP site??}. These approaches differ from the one taken by Anders Edenbrandt in that his method uses direct 8-bit input, while these methods use a compose sequence for 8-bit characters. {I have heard conflicting reports on whether this results in losing the Meta key. Perhaps this depends on whether Emacs is running under X. Can someone resolve this?} Karl Heuer <karl@haddock.ima.isc.com> is said to have a patch to allow 8-bit input. Georg-Wilhelm Koltermann <gwk@crmunich0.cray.com> also has a patch for either 18.57 or 18.58 that allows 8-bit input. Epoch comes with a patch that allows it to input 8-bit characters, but it is not enabled by default. {Is this right?} Jamie Zawinski says: Lucid GNU Emacs allows the input of any ISO-8859/1 keysyms that your keyboard generates (see xmodmap), and contains a package that implements a DEC/OpenWindows-like "Compose" key for systems which don't have one. 149: Where can I get an Emacs that can handle kanji characters? Nemacs 3.3.2 (Nihongo GNU Emacs) is a modified version of GNU Emacs 18.55 that handles kanji characters. It is available via anonymous FTP: /crl.nmsu.edu:pub/misc/nemacs-3.3.2.tar.Z /miki.cs.titech.ac.jp:JAPAN/nemacs/nemacs-3.3.2.tar.Z You might also need files for "wnn", a kanji input method (wnn-4.0.3{-README,.tar.Z} {on which machine?}). You need a terminal (or terminal emulator) that can display text encoded in JIS, Shift-JIS, or EUC (Extended Unix Code), or the ability to run Nemacs as a direct X Window client. 150: Where can I get an Emacs that can handle Chinese? `cemacs' by Stephen G. Simpson <simpson@math.psu.edu> is a patch to Emacs 18.57 (the ctl-arrow patch) and some Emacs Lisp code that combined with Cxterm allows using Chinese characters. It is available via anonymous FTP: /crl.nmsu.edu:pub/chinese/cemacs.tar.Z /cs.purdue.edu:pub/ygz/cemacs.tar.Z Cxterm is available from the same place: /cs.purdue.edu:pub/ygz/cxterm-11.5.1.tar.Z 151: Where is an Emacs that can handle Semitic (right-to-left) alphabets? Joel M. Hoffman <joel@wam.umd.edu> writes: A couple of years ago a wrote a hebrew.el file that allows right-to-left editing of Hebrew. I relied on the hardware to display the Hebrew letters, given the right codes, but not for any right-to-left support; the hardware also doesn't have to send any specific char. codes. Emacs keeps track of when the user is typing Hebrew vs. English. (The VT-* terminals in Israel contain built-in support for Hebrew.) To get it to work I had to modify only a few lines of GNU Emacs's source code --- just enough to make it 8-bit clean. [and in a separate message:] It doesn't produce time-order ["sefer" format] (I wouldn't recommend trying that with emacs, because converting time-order to screen-order with arbitrarily long lines is a bit tricky), but I also concocted a quick filter to convert screen-order into time-order. I'll be happy to send you the requisite files if you want them. If you're using it for anything large, however, you'll want something that works better. Joel Hoffman has also written a "bi-directional bi-lingual Emacs-like" editor for MS-DOS named Ibelbe (Itty Bitty Emacs-Like Bidirectional Editor). Ibelbe is written in Turbo Pascal and comes with source code. Here is the description: Ibelbe looks like emacs (it even has a minibuffer and filename completion), and fully supports both right-to-left and left-to-right editing. Other than an EGA monitor or better, no special hardware is required. You will need an EGA Hebrew font to use Ibelbe with Hebrew. Anonymous FTP: /israel.nysernet.org:israel/msdos/ibelbe.zip /israel.nysernet.org:israel/msdos/hebfont.zip Joseph Friedman <yossi@deshaw.com, yossi@Neon.Stanford.EDU> has written patches for Emacs 18.55 and 18.58 that provide Semitic language support under X Windows. Warren Burstein <warren@itex.jct.ac.il> says he has mapped 7-bit keys by modifying self-insert-command "for Hebrew input on 7-bit keyboards". A good suggestion is to query archie for files named with `hebrew'. ---------------------------------------------------------------------- Copyright (C) 1990, 1991, 1992 Joseph Brian Wells Copyright (C) 1992, 1993 Steven Byrnes This list of frequently asked questions about GNU Emacs with answers ("FAQ") may be translated into other languages, transformed into other formats (e.g. Texinfo, Info, WWW, WAIS, etc.), and updated with new information. The same conditions apply to any derivative of the FAQ as apply to the FAQ itself. Every copy of the FAQ must include this notice or an approved translation, information on who is currently maintaining the FAQ and how to contact them (including their e-mail address), and information on where the latest version of the FAQ is archived (including FTP information). The FAQ may be copied and redistributed under these conditions, except that the FAQ may not be embedded in a larger literary work unless that work itself allows free copying and redistribution.