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Emacs and MS-DOS

This section briefly describes the peculiarities of using Emacs under the MS-DOS "operating system" (also known as "MS-DOG"). If you build Emacs for MS-DOS, the binary will also run on Windows 3, Windows NT, Windows 95, or OS-2 as a DOS application; the information in this chapter applies for all of those systems, if you use an Emacs that was built for MS-DOS. Note that it is possible to build Emacs specifically for Windows NT or Windows 95. If you do that, most of this chapter does not apply; instead, you get behavior much closer to what is documented in the rest of the manual, including support for long file names, multiple frames, scroll bars, mouse menus, and subprocesses. However, the section on text files and binary files does still apply. There are also two sections at the end of this chapter which apply specifically for Windows NT and 95. Keyboard and Mouse on MS-DOS

The PC keyboard maps use the left ALT key as the META key. You have two choices for emulating the SUPER and HYPER keys: choose either the right CTRL key or the right ALT key by setting the variables dos-hyper-key and dos-super-key to 1 or 2 respectively. If neither dos-super-key nor dos-hyper-key is 1, then by default the right ALT key is also mapped to the META key. However, if the MS-DOS international keyboard support program `KEYB.COM' is installed, Emacs will not map the right ALT to META, since it is used for accessing characters like ~ and on non-US keyboard layouts; in this case, you may only use the left ALT as META key. The variable dos-keypad-mode is a flag variable that controls what key codes are returned by keys in the numeric keypad. You can also define the keypad ENTER key to act like C-j, by putting the following line into your `_emacs' file: ;; Make the Enter key from the Numeric keypad act as C-j. (define-key function-key-map [kp-enter] [?\C-j])

The key that is called DEL in Emacs (because that's how it is designated on most workstations) is known as BS (backspace) on a PC. That is why the PC-specific terminal initialization remaps the BS key to act as DEL; the DEL key is remapped to act as C-d for the same reasons. Emacs built for MS-DOS recognizes C-BREAK as a quit character, just like C-g. This is because Emacs cannot detect that you have typed C-g until it is ready for more input. As a consequence, you cannot use C-g to stop a running command (see section Quitting and Aborting). By contrast, C-BREAK is detected as soon as you type it (as C-g is on other systems), so it can be used to stop a running command and for emergency escape (see section Emergency Escape). Emacs on MS-DOS supports a mouse (on the default terminal only). The mouse commands work as documented, including those that use menus and the menu bar (see section The Menu Bar). Scroll bars don't work in MS-DOS Emacs. PC mice usually have only two buttons; these act as Mouse-1 and Mouse-2, but if you press both of them together, that has the effect of Mouse-3. Emacs built for MS-DOS supports clipboard operations when it runs on Windows. Commands that put text on the kill ring, or yank text from the ring, check the Windows clipboard first, just as Emacs does on X Windows (see section Mouse Commands for Editing). Only the primary selection and the cut buffer are supported by MS-DOS Emacs on Windows; the secondary selection always appears as empty. Due to the way clipboard access is implemented by Windows, the length of text you can put into the clipboard is limited by the amount of free DOS memory that is available to Emacs. Usually, up to 620KB of text can be put into the clipboard, but this limit depends on the system configuration and is lower if you run Emacs as a subprocess of another program. If the killed text does not fit, Emacs prints a message saying so, and does not put the text into the clipboard. The variable dos-display-scancodes, when non-nil, directs Emacs to display the ASCII value and the keyboard scan code of each keystroke; this feature serves as a complement to the view-lossage command, for debugging. Display on MS-DOS

Display on MS-DOS cannot use multiple fonts, but it does support multiple faces, each of which can specify a foreground and a background color. Therefore, you can get the full functionality of Emacs packages that use fonts (such as font-lock, Enriched Text mode, and others) by defining the relevant faces to use different colors. Use the list-colors-display command (see section Setting Frame Parameters) and the list-faces-display command (see section Using Multiple Typefaces) to see what colors and faces are available and what they look like. Multiple frames (see section Frames and X Windows) are supported on MS-DOS, but they all overlap, so you only see a single frame at any given moment. That single visible frame occupies the entire screen. When you run Emacs from MS-Windows DOS box, you can make the visible frame smaller than the full screen, but Emacs still cannot display more than a single frame at a time. The mode4350 command switches the display to 43 or 50 lines, depending on your hardware; the mode25 command switches to the default 80x25 screen size. By default, Emacs only knows how to set screen sizes of 80 columns by 25, 28, 35, 40, 43 or 50 rows. However, if your video adapter has special video modes that will switch the display to other sizes, you can have Emacs support those too. When you ask Emacs to switch the frame to n rows by m columns dimensions, it checks if there is a variable called screen-dimensions-nxm, and if so, uses its value (which must be an integer) as the video mode to switch to. (Emacs switches to that video mode by calling the BIOS Set Video Mode function with the value of screen-dimensions-nxm in the AL register.) For example, suppose your adapter will switch to 66x80 dimensions when put into video mode 85. Then you can make Emacs support this screen size by putting the following into your `_emacs' file: (setq screen-dimensions-66x80 85)

Since Emacs on MS-DOS can only set the frame size to specific supported dimensions, it cannot honor every possible frame resizing request. When an unsupported size is requested, Emacs chooses the next larger supported size beyond the specified size. For example, if you ask for 36x80 frame, you will get 40x80 instead. The variables screen-dimensions-nxm are used only when they exactly match the specified size; the search for the next larger supported size ignores them. In the above example, even if your VGA supports 38x80 dimensions and you define a variable screen-dimensions-38x80 with a suitable value, you will still get 40x80 screen when you ask for a 36x80 frame. If you want to get the 38x80 size in this case, you can do it by setting the variable named screen-dimensions-36x80 with the same video mode value as screen-dimensions-38x80. Changing frame dimensions on MS-DOS has the effect of changing all the other frames to the new dimensions. File Names on MS-DOS

MS-DOS normally uses a backslash, `\', to separate name units within a file name, instead of the slash used on other systems. Emacs on MS-DOS permits use of either slash or backslash, and also knows about drive letters in file names. On MS-DOS, file names are case-insensitive and limited to eight characters, plus optionally a period and three more characters. Emacs knows enough about these limitations to handle file names that were meant for other operating systems. For instance, leading dots `.' in file names are invalid in MS-DOS, so Emacs transparently converts them to underscores `_'; thus your default init file (see section The Init File, `~/.emacs') is called `_emacs' on MS-DOS. Excess characters before or after the period are generally ignored by MS-DOS itself; thus, if you visit the file `LongFileName.EvenLongerExtension', you will silently get `longfile.eve', but Emacs will still display the long file name on the mode line. Other than that, it's up to you to specify file names which are valid under MS-DOS; the transparent conversion as described above only works on file names built into Emacs. The above restrictions on the file names on MS-DOS make it almost impossible to construct the name of a backup file (see section Single or Numbered Backups) without losing some of the original file name characters. For example, the name of a backup file for `docs.txt' is `docs.tx~' even if single backup is used. If you run Emacs as a DOS application under Windows 9X, you can turn on support for long file names. If you do that, Emacs doesn't truncate file names or convert them to lower case; instead, it uses the file names that you specify, verbatim. To enable long file name support, set the environment variable LFN to `y' before starting Emacs. Unfortunately, Windows NT doesn't allow DOS programs to access long file names, so Emacs built for MS-DOS will only see their short 8+3 aliases. MS-DOS has no notion of home directory, so Emacs on MS-DOS pretends that the directory where it is installed is the value of HOME environment variable. That is, if your Emacs binary, `emacs.exe', is in the directory `c:/utils/emacs/bin', then Emacs acts as if HOME were set to `c:/utils/emacs'. In particular, that is where Emacs looks for the init file `_emacs'. With this in mind, you can use `~' in file names as an alias for the home directory, as you would in Unix. You can also set HOME variable in the environment before starting Emacs; its value will then override the above default behavior. Emacs on MS-DOS handles the directory name `/dev' specially, because of a feature in the emulator libraries of DJGPP that pretends I/O devices have names in that directory. We recommend that you avoid using an actual directory named `/dev' on any disk. Text Files and Binary Files

GNU Emacs uses newline characters to separate text lines. This is the convention used on Unix, on which GNU Emacs was developed, and on GNU systems since they are modeled on Unix. MS-DOS and MS-Windows normally use carriage-return linefeed, a two-character sequence, to separate text lines. (Linefeed is the same character as newline.) Therefore, convenient editing of typical files with Emacs requires conversion of these end-of-line (EOL) sequences. And that is what Emacs normally does: it converts carriage-return linefeed into newline when reading files, and converts newline into carriage-return linefeed when writing files. The same mechanism that handles conversion of international character codes does this conversion also (see section Coding Systems). One consequence of this special format-conversion of most files is that character positions as reported by Emacs (see section Cursor Position Information) do not agree with the file size information known to the operating system. Some kinds of files should not be converted, because their contents are not really text. Therefore, Emacs on MS-DOS distinguishes certain files as binary files, and reads and writes them verbatim. (This distinction is not part of MS-DOS; it is made by Emacs only.) These include executable programs, compressed archives, etc. Emacs uses the file name to decide whether to treat a file as binary: the variable file-name-buffer-file-type-alist defines the file-name patterns that indicate binary files. Note that if a file name matches one of the patterns for binary files in file-name-buffer-file-type-alist, Emacs uses the no-conversion coding system (see section Coding Systems) which turns off all coding-system conversions, not only the EOL conversion. In addition, if Emacs recognizes from a file's contents that it uses newline rather than carriage-return linefeed as its line separator, it does not perform conversion when reading or writing that file. Thus, you can read and edit files from Unix or GNU systems on MS-DOS with no special effort, and they will be left with their Unix-style EOLs. You can visit a file and specify whether to treat a file as text or binary using the commands find-file-text and find-file-binary. End-of-line conversion is part of the general coding system conversion mechanism, so another way to control whether to treat a file as text or binary is with the commands for specifying a coding system (see section Specifying a Coding System). For example, C-x RET c undecided-unix RET C-x C-f foobar.txt visits the file `foobar.txt' without converting the EOLs. The mode line indicates whether end-of-line translation was used for the current buffer. Normally a colon appears after the coding system letter near the beginning of the mode line. If MS-DOS end-of-line translation is in use for the buffer, this character changes to a backslash. When you use NFS or Samba to access file systems that reside on computers using Unix or GNU systems, Emacs should not perform end-of-line translation on any files in these file systems--not even when you create a new file. To request this, designate these file systems as untranslated file systems by calling the function add-untranslated-filesystem. It takes one argument: the file system name, including a drive letter and optionally a directory. For example, (add-untranslated-filesystem "Z:")

designates drive Z as an untranslated file system, and (add-untranslated-filesystem "Z:\\foo")

designates directory `\foo' on drive Z as an untranslated file system. Most often you would use add-untranslated-filesystem in your `_emacs' file, or in `site-start.el' so that all the users at your site get the benefit of it. To countermand the effect of add-untranslated-filesystem, use the function remove-untranslated-filesystem. This function takes one argument, which should be a string just like the one that was used previously with add-untranslated-filesystem. Printing and MS-DOS

Printing commands, such as lpr-buffer (see section Hardcopy Output) and ps-print-buffer (see section Postscript Hardcopy) can work in MS-DOS by sending the output to one of the printer ports, if a Unix-style lpr program is unavailable. A few DOS-specific variables control how this works. If you want to use your local printer, printing on it in the usual DOS manner, then set the Lisp variable dos-printer to the name of the printer port--for example, "PRN", the usual local printer port (that's the default), or "LPT2" or "COM1" for a serial printer. You can also set dos-printer to a file name, in which case "printed" output is actually appended to that file. If you set dos-printer to "NUL", printed output is silently discarded (sent to the system null device). If you set dos-printer to a file name, it's best to use an absolute file name. Emacs changes the working directory according to the default directory of the current buffer, so if the file name in dos-printer is relative, you will end up with several such files, each one in the directory of the buffer from which the printing was done. The commands print-buffer and print-region call the pr program, or use special switches to the lpr program, to produce headers on each printed page. MS-DOS doesn't normally have these programs, so by default, the variable lpr-headers-switches is set so that the requests to print page headers are silently ignored. Thus, print-buffer and print-region produce the same output as lpr-buffer and lpr-region, respectively. If you do have a suitable pr program (for example, from GNU Textutils), set lpr-headers-switches to nil; Emacs will then call pr to produce the page headers, and print the resulting output as specified by dos-printer. Finally, if you do have an lpr work-alike, you can set print-region-function to nil. Then Emacs uses lpr for printing, as on other systems. (If the name of the program isn't lpr, set the lpr-command variable to specify where to find it.) A separate variable, dos-ps-printer, defines how PostScript files should be printed. If its value is a string, it is used as the name of the device (or file) to which PostScript output is sent, just as dos-printer is used for non-PostScript printing. (These are two distinct variables in case you have two printers attached to two different ports, and only one of them is a PostScript printer.) If the value of dos-ps-printer is not a string, then the variables ps-lpr-command and ps-lpr-switches (see section Postscript Hardcopy) control how to print PostScript files. Thus, if you have a non-PostScript printer, you can set these variables to the name and the switches appropriate for a PostScript interpreter program (such as Ghostscript). For example, to use Ghostscript for printing on an Epson printer connected to `LPT2' port, put this on your `.emacs' file: (setq dos-ps-printer t) ; Anything but a string. (setq ps-lpr-command "c:/gs/gs386") (setq ps-lpr-switches '("-q" "-dNOPAUSE" "-sDEVICE=epson" "-r240x72" "-sOutputFile=LPT2" "-Ic:/gs" "-"))

(This assumes that Ghostscript is installed in the `"c:/gs"' directory.) Subprocesses on MS-DOS

Because MS-DOS is a single-process "operating system," asynchronous subprocesses are not available. In particular, Shell mode and its variants do not work. Most Emacs features that use asynchronous subprocesses also don't work on MS-DOS, including spelling correction and GUD. When in doubt, try and see; commands that don't work print an error message saying that asynchronous processes aren't supported. Compilation under Emacs with M-x compile, searching files with M-x grep and displaying differences between files with M-x diff do work, by running the inferior processes synchronously. This means you cannot do any more editing until the inferior process finishes. By contrast, Emacs compiled as native Windows application does support asynchronous subprocesses. See section Subprocesses on Windows 95 and NT. Printing commands, such as lpr-buffer (see section Hardcopy Output) and ps-print-buffer (see section Postscript Hardcopy), work in MS-DOS by sending the output to one of the printer ports. See section Printing and MS-DOS. When you run a subprocess synchronously on MS-DOS, make sure the program terminates and does not try to read keyboard input. If the program does not terminate on its own, you will be unable to terminate it, because MS-DOS provides no general way to terminate a process. Pressing C-c or C-BREAK might sometimes help in these cases. Accessing files on other machines is not supported on MS-DOS. Other network-oriented commands such as sending mail, Web browsing, remote login, etc., don't work either, unless network access is built into MS-DOS with some network redirector. Dired on MS-DOS uses the ls-lisp package where other platforms use the system ls command. Therefore, Dired on MS-DOS supports only some of the possible options you can mention in the dired-listing-switches variable. The options that work are `-A', `-a', `-c', `-i', `-r', `-S', `-s', `-t', and `-u'. Subprocesses on Windows 95 and NT

Emacs compiled as a native Windows application (as opposed to the DOS version) includes full support for asynchronous subprocesses. In the Windows version, synchronous and asynchronous subprocesses work fine on both Windows 95 and Windows NT as long as you run only 32-bit Windows applications. However, when you run a DOS application in a subprocess, you may encounter problems or be unable to run the application at all; and if you run two DOS applications at the same time in two subprocesses, you may have to reboot your system. Since the standard command interpreter (and most command line utilities) on Windows 95 are DOS applications, these problems are significant when using that system. But there's nothing we can do about them; only Microsoft can fix them. If you run just one DOS application subprocess, the subprocess should work as expected as long as it is "well-behaved" and does not perform direct screen access or other unusual actions. If you have a CPU monitor application, your machine will appear to be 100% busy even when the DOS application is idle, but this is only an artifact of the way CPU monitors measure processor load. You must terminate the DOS application before you start any other DOS application in a different subprocess. Emacs is unable to interrupt or terminate a DOS subprocess. The only way you can terminate such a subprocess is by giving it a command that tells its program to exit. If you attempt to run two DOS applications at the same time in separate subprocesses, the second one that is started will be suspended until the first one finishes, even if either or both of them are asynchronous. If you can go to the first subprocess, and tell it to exit, the second subprocess should continue normally. However, if the second subprocess is synchronous, Emacs itself will be hung until the first subprocess finishes. If it will not finish without user input, then you have no choice but to reboot if you are running on Windows 95. If you are running on Windows NT, you can use a process viewer application to kill the appropriate instance of ntvdm instead (this will terminate both DOS subprocesses). If you have to reboot Windows 95 in this situation, do not use the Shutdown command on the Start menu; that usually hangs the system. Instead, type CTL-ALT-DEL and then choose Shutdown. That usually works, although it may take a few minutes to do its job. Using the System Menu on Windows

Emacs compiled as a native Windows application normally turns off the Windows feature that tapping the ALT key invokes the Windows menu. The reason is that the ALT also serves as META in Emacs. When using Emacs, users often press the META key temporarily and then change their minds; if this has the effect of bringing up the Windows menu, it alters the meaning of subsequent commands. Many users find this frustrating. You can reenable Windows's default handling of tapping the ALT key by setting w32-pass-alt-to-system to a non-nil value. The GNU Manifesto The GNU Manifesto which appears below was written by Richard Stallman at the beginning of the GNU project, to ask for participation and support. For the first few years, it was updated in minor ways to account for developments, but now it seems best to leave it unchanged as most people have seen it. Since that time, we have learned about certain common misunderstandings that different wording could help avoid. Footnotes added in 1993 help clarify these points. For up-to-date information about the available GNU software, please see the latest issue of the GNU's Bulletin. The list is much too long to include here. What's GNU? Gnu's Not Unix!

GNU, which stands for Gnu's Not Unix, is the name for the complete Unix-compatible software system which I am writing so that I can give it away free to everyone who can use it.(5) Several other volunteers are helping me. Contributions of time, money, programs and equipment are greatly needed. So far we have an Emacs text editor with Lisp for writing editor commands, a source level debugger, a yacc-compatible parser generator, a linker, and around 35 utilities. A shell (command interpreter) is nearly completed. A new portable optimizing C compiler has compiled itself and may be released this year. An initial kernel exists but many more features are needed to emulate Unix. When the kernel and compiler are finished, it will be possible to distribute a GNU system suitable for program development. We will use TeX as our text formatter, but an nroff is being worked on. We will use the free, portable X window system as well. After this we will add a portable Common Lisp, an Empire game, a spreadsheet, and hundreds of other things, plus on-line documentation. We hope to supply, eventually, everything useful that normally comes with a Unix system, and more. GNU will be able to run Unix programs, but will not be identical to Unix. We will make all improvements that are convenient, based on our experience with other operating systems. In particular, we plan to have longer file names, file version numbers, a crashproof file system, file name completion perhaps, terminal-independent display support, and perhaps eventually a Lisp-based window system through which several Lisp programs and ordinary Unix programs can share a screen. Both C and Lisp will be available as system programming languages. We will try to support UUCP, MIT Chaosnet, and Internet protocols for communication. GNU is aimed initially at machines in the 68000/16000 class with virtual memory, because they are the easiest machines to make it run on. The extra effort to make it run on smaller machines will be left to someone who wants to use it on them. To avoid horrible confusion, please pronounce the `G' in the word `GNU' when it is the name of this project. Why I Must Write GNU

I consider that the golden rule requires that if I like a program I must share it with other people who like it. Software sellers want to divide the users and conquer them, making each user agree not to share with others. I refuse to break solidarity with other users in this way. I cannot in good conscience sign a nondisclosure agreement or a software license agreement. For years I worked within the Artificial Intelligence Lab to resist such tendencies and other inhospitalities, but eventually they had gone too far: I could not remain in an institution where such things are done for me against my will. So that I can continue to use computers without dishonor, I have decided to put together a sufficient body of free software so that I will be able to get along without any software that is not free. I have resigned from the AI lab to deny MIT any legal excuse to prevent me from giving GNU away. Why GNU Will Be Compatible with Unix

Unix is not my ideal system, but it is not too bad. The essential features of Unix seem to be good ones, and I think I can fill in what Unix lacks without spoiling them. And a system compatible with Unix would be convenient for many other people to adopt. How GNU Will Be Available

GNU is not in the public domain. Everyone will be permitted to modify and redistribute GNU, but no distributor will be allowed to restrict its further redistribution. That is to say, proprietary modifications will not be allowed. I want to make sure that all versions of GNU remain free. Why Many Other Programmers Want to Help

I have found many other programmers who are excited about GNU and want to help. Many programmers are unhappy about the commercialization of system software. It may enable them to make more money, but it requires them to feel in conflict with other programmers in general rather than feel as comrades. The fundamental act of friendship among programmers is the sharing of programs; marketing arrangements now typically used essentially forbid programmers to treat others as friends. The purchaser of software must choose between friendship and obeying the law. Naturally, many decide that friendship is more important. But those who believe in law often do not feel at ease with either choice. They become cynical and think that programming is just a way of making money. By working on and using GNU rather than proprietary programs, we can be hospitable to everyone and obey the law. In addition, GNU serves as an example to inspire and a banner to rally others to join us in sharing. This can give us a feeling of harmony which is impossible if we use software that is not free. For about half the programmers I talk to, this is an important happiness that money cannot replace. How You Can Contribute

I am asking computer manufacturers for donations of machines and money. I'm asking individuals for donations of programs and work. One consequence you can expect if you donate machines is that GNU will run on them at an early date. The machines should be complete, ready to use systems, approved for use in a residential area, and not in need of sophisticated cooling or power. I have found very many programmers eager to contribute part-time work for GNU. For most projects, such part-time distributed work would be very hard to coordinate; the independently-written parts would not work together. But for the particular task of replacing Unix, this problem is absent. A complete Unix system contains hundreds of utility programs, each of which is documented separately. Most interface specifications are fixed by Unix compatibility. If each contributor can write a compatible replacement for a single Unix utility, and make it work properly in place of the original on a Unix system, then these utilities will work right when put together. Even allowing for Murphy to create a few unexpected problems, assembling these components will be a feasible task. (The kernel will require closer communication and will be worked on by a small, tight group.) If I get donations of money, I may be able to hire a few people full or part time. The salary won't be high by programmers' standards, but I'm looking for people for whom building community spirit is as important as making money. I view this as a way of enabling dedicated people to devote their full energies to working on GNU by sparing them the need to make a living in another way. Why All Computer Users Will Benefit

Once GNU is written, everyone will be able to obtain good system software free, just like air.(6) This means much more than just saving everyone the price of a Unix license. It means that much wasteful duplication of system programming effort will be avoided. This effort can go instead into advancing the state of the art. Complete system sources will be available to everyone. As a result, a user who needs changes in the system will always be free to make them himself, or hire any available programmer or company to make them for him. Users will no longer be at the mercy of one programmer or company which owns the sources and is in sole position to make changes. Schools will be able to provide a much more educational environment by encouraging all students to study and improve the system code. Harvard's computer lab used to have the policy that no program could be installed on the system if its sources were not on public display, and upheld it by actually refusing to install certain programs. I was very much inspired by this. Finally, the overhead of considering who owns the system software and what one is or is not entitled to do with it will be lifted. Arrangements to make people pay for using a program, including licensing of copies, always incur a tremendous cost to society through the cumbersome mechanisms necessary to figure out how much (that is, which programs) a person must pay for. And only a police state can force everyone to obey them. Consider a space station where air must be manufactured at great cost: charging each breather per liter of air may be fair, but wearing the metered gas mask all day and all night is intolerable even if everyone can afford to pay the air bill. And the TV cameras everywhere to see if you ever take the mask off are outrageous. It's better to support the air plant with a head tax and chuck the masks. Copying all or parts of a program is as natural to a programmer as breathing, and as productive. It ought to be as free. Some Easily Rebutted Objections to GNU's Goals

"Nobody will use it if it is free, because that means they can't rely on any support." "You have to charge for the program to pay for providing the support." If people would rather pay for GNU plus service than get GNU free without service, a company to provide just service to people who have obtained GNU free ought to be profitable.(7) We must distinguish between support in the form of real programming work and mere handholding. The former is something one cannot rely on from a software vendor. If your problem is not shared by enough people, the vendor will tell you to get lost. If your business needs to be able to rely on support, the only way is to have all the necessary sources and tools. Then you can hire any available person to fix your problem; you are not at the mercy of any individual. With Unix, the price of sources puts this out of consideration for most businesses. With GNU this will be easy. It is still possible for there to be no available competent person, but this problem cannot be blamed on distribution arrangements. GNU does not eliminate all the world's problems, only some of them. Meanwhile, the users who know nothing about computers need handholding: doing things for them which they could easily do themselves but don't know how. Such services could be provided by companies that sell just hand-holding and repair service. If it is true that users would rather spend money and get a product with service, they will also be willing to buy the service having got the product free. The service companies will compete in quality and price; users will not be tied to any particular one. Meanwhile, those of us who don't need the service should be able to use the program without paying for the service. "You cannot reach many people without advertising, and you must charge for the program to support that." "It's no use advertising a program people can get free." There are various forms of free or very cheap publicity that can be used to inform numbers of computer users about something like GNU. But it may be true that one can reach more microcomputer users with advertising. If this is really so, a business which advertises the service of copying and mailing GNU for a fee ought to be successful enough to pay for its advertising and more. This way, only the users who benefit from the advertising pay for it. On the other hand, if many people get GNU from their friends, and such companies don't succeed, this will show that advertising was not really necessary to spread GNU. Why is it that free market advocates don't want to let the free market decide this?(8) "My company needs a proprietary operating system to get a competitive edge." GNU will remove operating system software from the realm of competition. You will not be able to get an edge in this area, but neither will your competitors be able to get an edge over you. You and they will compete in other areas, while benefiting mutually in this one. If your business is selling an operating system, you will not like GNU, but that's tough on you. If your business is something else, GNU can save you from being pushed into the expensive business of selling operating systems. I would like to see GNU development supported by gifts from many manufacturers and users, reducing the cost to each.(9) "Don't programmers deserve a reward for their creativity?" If anything deserves a reward, it is social contribution. Creativity can be a social contribution, but only in so far as society is free to use the results. If programmers deserve to be rewarded for creating innovative programs, by the same token they deserve to be punished if they restrict the use of these programs. "Shouldn't a programmer be able to ask for a reward for his creativity?" There is nothing wrong with wanting pay for work, or seeking to maximize one's income, as long as one does not use means that are destructive. But the means customary in the field of software today are based on destruction. Extracting money from users of a program by restricting their use of it is destructive because the restrictions reduce the amount and the ways that the program can be used. This reduces the amount of wealth that humanity derives from the program. When there is a deliberate choice to restrict, the harmful consequences are deliberate destruction. The reason a good citizen does not use such destructive means to become wealthier is that, if everyone did so, we would all become poorer from the mutual destructiveness. This is Kantian ethics; or, the Golden Rule. Since I do not like the consequences that result if everyone hoards information, I am required to consider it wrong for one to do so. Specifically, the desire to be rewarded for one's creativity does not justify depriving the world in general of all or part of that creativity. "Won't programmers starve?" I could answer that nobody is forced to be a programmer. Most of us cannot manage to get any money for standing on the street and making faces. But we are not, as a result, condemned to spend our lives standing on the street making faces, and starving. We do something else. But that is the wrong answer because it accepts the questioner's implicit assumption: that without ownership of software, programmers cannot possibly be paid a cent. Supposedly it is all or nothing. The real reason programmers will not starve is that it will still be possible for them to get paid for programming; just not paid as much as now. Restricting copying is not the only basis for business in software. It is the most common basis because it brings in the most money. If it were prohibited, or rejected by the customer, software business would move to other bases of organization which are now used less often. There are always numerous ways to organize any kind of business. Probably programming will not be as lucrative on the new basis as it is now. But that is not an argument against the change. It is not considered an injustice that sales clerks make the salaries that they now do. If programmers made the same, that would not be an injustice either. (In practice they would still make considerably more than that.) "Don't people have a right to control how their creativity is used?" "Control over the use of one's ideas" really constitutes control over other people's lives; and it is usually used to make their lives more difficult. People who have studied the issue of intellectual property rights carefully (such as lawyers) say that there is no intrinsic right to intellectual property. The kinds of supposed intellectual property rights that the government recognizes were created by specific acts of legislation for specific purposes. For example, the patent system was established to encourage inventors to disclose the details of their inventions. Its purpose was to help society rather than to help inventors. At the time, the life span of 17 years for a patent was short compared with the rate of advance of the state of the art. Since patents are an issue only among manufacturers, for whom the cost and effort of a license agreement are small compared with setting up production, the patents often do not do much harm. They do not obstruct most individuals who use patented products. The idea of copyright did not exist in ancient times, when authors frequently copied other authors at length in works of non-fiction. This practice was useful, and is the only way many authors' works have survived even in part. The copyright system was created expressly for the purpose of encouraging authorship. In the domain for which it was invented--books, which could be copied economically only on a printing press--it did little harm, and did not obstruct most of the individuals who read the books. All intellectual property rights are just licenses granted by society because it was thought, rightly or wrongly, that society as a whole would benefit by granting them. But in any particular situation, we have to ask: are we really better off granting such license? What kind of act are we licensing a person to do? The case of programs today is very different from that of books a hundred years ago. The fact that the easiest way to copy a program is from one neighbor to another, the fact that a program has both source code and object code which are distinct, and the fact that a program is used rather than read and enjoyed, combine to create a situation in which a person who enforces a copyright is harming society as a whole both materially and spiritually; in which a person should not do so regardless of whether the law enables him to. "Competition makes things get done better." The paradigm of competition is a race: by rewarding the winner, we encourage everyone to run faster. When capitalism really works this way, it does a good job; but its defenders are wrong in assuming it always works this way. If the runners forget why the reward is offered and become intent on winning, no matter how, they may find other strategies--such as, attacking other runners. If the runners get into a fist fight, they will all finish late. Proprietary and secret software is the moral equivalent of runners in a fist fight. Sad to say, the only referee we've got does not seem to object to fights; he just regulates them ("For every ten yards you run, you can fire one shot"). He really ought to break them up, and penalize runners for even trying to fight. "Won't everyone stop programming without a monetary incentive?" Actually, many people will program with absolutely no monetary incentive. Programming has an irresistible fascination for some people, usually the people who are best at it. There is no shortage of professional musicians who keep at it even though they have no hope of making a living that way. But really this question, though commonly asked, is not appropriate to the situation. Pay for programmers will not disappear, only become less. So the right question is, will anyone program with a reduced monetary incentive? My experience shows that they will. For more than ten years, many of the world's best programmers worked at the Artificial Intelligence Lab for far less money than they could have had anywhere else. They got many kinds of non-monetary rewards: fame and appreciation, for example. And creativity is also fun, a reward in itself. Then most of them left when offered a chance to do the same interesting work for a lot of money. What the facts show is that people will program for reasons other than riches; but if given a chance to make a lot of money as well, they will come to expect and demand it. Low-paying organizations do poorly in competition with high-paying ones, but they do not have to do badly if the high-paying ones are banned. "We need the programmers desperately. If they demand that we stop helping our neighbors, we have to obey." You're never so desperate that you have to obey this sort of demand. Remember: millions for defense, but not a cent for tribute! "Programmers need to make a living somehow." In the short run, this is true. However, there are plenty of ways that programmers could make a living without selling the right to use a program. This way is customary now because it brings programmers and businessmen the most money, not because it is the only way to make a living. It is easy to find other ways if you want to find them. Here are a number of examples. A manufacturer introducing a new computer will pay for the porting of operating systems onto the new hardware. The sale of teaching, hand-holding and maintenance services could also employ programmers. People with new ideas could distribute programs as freeware, asking for donations from satisfied users, or selling hand-holding services. I have met people who are already working this way successfully. Users with related needs can form users' groups, and pay dues. A group would contract with programming companies to write programs that the group's members would like to use. All sorts of development can be funded with a Software Tax: Suppose everyone who buys a computer has to pay x percent of the price as a software tax. The government gives this to an agency like the NSF to spend on software development. But if the computer buyer makes a donation to software development himself, he can take a credit against the tax. He can donate to the project of his own choosing--often, chosen because he hopes to use the results when it is done. He can take a credit for any amount of donation up to the total tax he had to pay. The total tax rate could be decided by a vote of the payers of the tax, weighted according to the amount they will be taxed on. The consequences: The computer-using community supports software development. This community decides what level of support is needed. Users who care which projects their share is spent on can choose this for themselves. In the long run, making programs free is a step toward the post-scarcity world, where nobody will have to work very hard just to make a living. People will be free to devote themselves to activities that are fun, such as programming, after spending the necessary ten hours a week on required tasks such as legislation, family counseling, robot repair and asteroid prospecting. There will be no need to be able to make a living from programming. We have already greatly reduced the amount of work that the whole society must do for its actual productivity, but only a little of this has translated itself into leisure for workers because much nonproductive activity is required to accompany productive activity. The main causes of this are bureaucracy and isometric struggles against competition. Free software will greatly reduce these drains in the area of software production. We must do this, in order for technical gains in productivity to translate into less work for us. Glossary Abbrev An abbrev is a text string which expands into a different text string when present in the buffer. For example, you might define a few letters as an abbrev for a long phrase that you want to insert frequently. See section Abbrevs. Aborting Aborting means getting out of a recursive edit (q.v.). The commands C-] and M-x top-level are used for this. See section Quitting and Aborting. Alt Alt is the name of a modifier bit which a keyboard input character may have. To make a character Alt, type it while holding down the ALT key. Such characters are given names that start with Alt- (usually written A- for short). (Note that many terminals have a key labeled ALT which is really a META key.) See section Kinds of User Input. ASCII character An ASCII character is either an ASCII control character or an ASCII printing character. See section Kinds of User Input. ASCII control character An ASCII control character is the Control version of an upper-case letter, or the Control version of one of the characters `@[\]^_?'. ASCII printing character ASCII printing characters include letters, digits, space, and these punctuation characters: `!@#$%^& ()_-+=|\~` {}[]:;"' <>,.?/'. Auto Fill Mode Auto Fill mode is a minor mode in which text that you insert is automatically broken into lines of fixed width. See section Filling Text. Auto Saving Auto saving is the practice of saving the contents of an Emacs buffer in a specially-named file, so that the information will not be lost if the buffer is lost due to a system error or user error. See section Auto-Saving: Protection Against Disasters. Backup File A backup file records the contents that a file had before the current editing session. Emacs makes backup files automatically to help you track down or cancel changes you later regret making. See section Backup Files. Balance Parentheses Emacs can balance parentheses manually or automatically. Manual balancing is done by the commands to move over balanced expressions (see section Lists and Sexps). Automatic balancing is done by blinking or highlighting the parenthesis that matches one just inserted (see section Automatic Display Of Matching Parentheses). Bind To bind a key sequence means to give it a binding (q.v.). See section Changing Key Bindings Interactively. Binding A key sequence gets its meaning in Emacs by having a binding, which is a command (q.v.), a Lisp function that is run when the user types that sequence. See section Keys and Commands. Customization often involves rebinding a character to a different command function. The bindings of all key sequences are recorded in the keymaps (q.v.). See section Keymaps. Blank Lines Blank lines are lines that contain only whitespace. Emacs has several commands for operating on the blank lines in the buffer. Buffer The buffer is the basic editing unit; one buffer corresponds to one text being edited. You can have several buffers, but at any time you are editing only one, the `selected' buffer, though several can be visible when you are using multiple windows (q.v.). Most buffers are visiting (q.v.) some file. See section Using Multiple Buffers. Buffer Selection History Emacs keeps a buffer selection history which records how recently each Emacs buffer has been selected. This is used for choosing a buffer to select. See section Using Multiple Buffers. Button Down Event A button down event is the kind of input event generated right away when you press a mouse button. See section Rebinding Mouse Buttons. C- C- in the name of a character is an abbreviation for Control. See section Kinds of User Input. C-M- C-M- in the name of a character is an abbreviation for Control-Meta. See section Kinds of User Input. Case Conversion Case conversion means changing text from upper case to lower case or vice versa. See section Case Conversion Commands, for the commands for case conversion. Character Characters form the contents of an Emacs buffer; see section Character Set for Text. Also, key sequences (q.v.) are usually made up of characters (though they may include other input events as well). See section Kinds of User Input. Character Set Emacs supports a number of character sets, each of which represents a particular alphabet or script. See section International Character Set Support. Click Event A click event is the kind of input event generated when you press a mouse button and release it without moving the mouse. See section Rebinding Mouse Buttons. Coding System A coding system is an encoding for representing text characters in a file or in a stream of information. Emacs has the ability to convert text to or from a variety of coding systems when reading or writing it. See section Coding Systems. Command A command is a Lisp function specially defined to be able to serve as a key binding in Emacs. When you type a key sequence (q.v.), its binding (q.v.) is looked up in the relevant keymaps (q.v.) to find the command to run. See section Keys and Commands. Command Name A command name is the name of a Lisp symbol which is a command (see section Keys and Commands). You can invoke any command by its name using M-x (see section Running Commands by Name). Comment A comment is text in a program which is intended only for humans reading the program, and which is marked specially so that it will be ignored when the program is loaded or compiled. Emacs offers special commands for creating, aligning and killing comments. See section Manipulating Comments. Compilation Compilation is the process of creating an executable program from source code. Emacs has commands for compiling files of Emacs Lisp code (see section `Byte Compilation' in the Emacs Lisp Reference Manual) and programs in C and other languages (see section Running Compilations under Emacs). Complete Key A complete key is a key sequence which fully specifies one action to be performed by Emacs. For example, X and C-f and C-x m are complete keys. Complete keys derive their meanings from being bound (q.v.) to commands (q.v.). Thus, X is conventionally bound to a command to insert `X' in the buffer; C-x m is conventionally bound to a command to begin composing a mail message. See section Keys. Completion Completion is what Emacs does when it automatically fills out an abbreviation for a name into the entire name. Completion is done for minibuffer (q.v.) arguments when the set of possible valid inputs is known; for example, on command names, buffer names, and file names. Completion occurs when TAB, SPC or RET is typed. See section Completion. Continuation Line When a line of text is longer than the width of the window, it takes up more than one screen line when displayed. We say that the text line is continued, and all screen lines used for it after the first are called continuation lines. See section Basic Editing Commands. Control Character A control character is a character that you type by holding down the CTRL key. Some control characters also have their own keys, so that you can type them without using CTRL. For example, RET, TAB, ESC and DEL are all control characters. See section Kinds of User Input. Copyleft A copyleft is a notice giving the public legal permission to redistribute a program or other work of art. Copylefts are used by left-wing programmers to promote freedom and cooperation, just as copyrights are used by right-wing programmers to gain power over other people. The particular form of copyleft used by the GNU project is called the GNU General Public License. See section GNU GENERAL PUBLIC LICENSE. Current Buffer The current buffer in Emacs is the Emacs buffer on which most editing commands operate. You can select any Emacs buffer as the current one. See section Using Multiple Buffers. Current Line The line point is on (see section Point). Current Paragraph The paragraph that point is in. If point is between paragraphs, the current paragraph is the one that follows point. See section Paragraphs. Current Defun The defun (q.v.) that point is in. If point is between defuns, the current defun is the one that follows point. See section Defuns. Cursor The cursor is the rectangle on the screen which indicates the position called point (q.v.) at which insertion and deletion takes place. The cursor is on or under the character that follows point. Often people speak of `the cursor' when, strictly speaking, they mean `point'. See section Basic Editing Commands. Customization Customization is making minor changes in the way Emacs works. It is often done by setting variables (see section Variables) or by rebinding key sequences (see section Keymaps). Default Argument The default for an argument is the value that will be assumed if you do not specify one. When the minibuffer is used to read an argument, the default argument is used if you just type RET. See section The Minibuffer. Default Directory When you specify a file name that does not start with `/' or `~', it is interpreted relative to the current buffer's default directory. See section Minibuffers for File Names. Defun A defun is a list at the top level of parenthesis or bracket structure in a program. It is so named because most such lists in Lisp programs are calls to the Lisp function defun. See section Defuns. DEL DEL is a character that runs the command to delete one character of text. See section Basic Editing Commands. Deletion Deletion means erasing text without copying it into the kill ring (q.v.). The alternative is killing (q.v.). See section Deletion and Killing. Deletion of Files Deleting a file means erasing it from the file system. See section Miscellaneous File Operations. Deletion of Messages Deleting a message means flagging it to be eliminated from your mail file. Until you expunge (q.v.) the Rmail file, you can still undelete the messages you have deleted. See section Deleting Messages. Deletion of Windows Deleting a window means eliminating it from the screen. Other windows expand to use up the space. The deleted window can never come back, but no actual text is thereby lost. See section Multiple Windows. Directory File directories are named collections in the file system, within which you can place individual files or subdirectories. See section File Directories. Dired Dired is the Emacs facility that displays the contents of a file directory and allows you to "edit the directory," performing operations on the files in the directory. See section Dired, the Directory Editor. Disabled Command A disabled command is one that you may not run without special confirmation. The usual reason for disabling a command is that it is confusing for beginning users. See section Disabling Commands. Down Event Short for `button down event'. Drag Event A drag event is the kind of input event generated when you press a mouse button, move the mouse, and then release the button. See section Rebinding Mouse Buttons. Dribble File A file into which Emacs writes all the characters that the user types on the keyboard. Dribble files are used to make a record for debugging Emacs bugs. Emacs does not make a dribble file unless you tell it to. See section Reporting Bugs. Echo Area The echo area is the bottom line of the screen, used for echoing the arguments to commands, for asking questions, and printing brief messages (including error messages). The messages are stored in the buffer `Messages' so you can review them later. See section The Echo Area. Echoing Echoing is acknowledging the receipt of commands by displaying them (in the echo area). Emacs never echoes single-character key sequences; longer key sequences echo only if you pause while typing them. Electric We say that a character is electric if it is normally self-inserting (q.v.), but the current major mode (q.v.) redefines it to do something else as well. For example, some programming language major modes define particular delimiter characters to reindent the line or insert one or more newlines in addition to self-insertion. Error An error occurs when an Emacs command cannot execute in the current circumstances. When an error occurs, execution of the command stops (unless the command has been programmed to do otherwise) and Emacs reports the error by printing an error message (q.v.). Type-ahead is discarded. Then Emacs is ready to read another editing command. Error Message An error message is a single line of output displayed by Emacs when the user asks for something impossible to do (such as, killing text forward when point is at the end of the buffer). They appear in the echo area, accompanied by a beep. ESC ESC is a character used as a prefix for typing Meta characters on keyboards lacking a META key. Unlike the META key (which, like the SHIFT key, is held down while another character is typed), you press the ESC key as you would press a letter key, and it applies to the next character you type. Expunging Expunging an Rmail file or Dired buffer is an operation that truly discards the messages or files you have previously flagged for deletion. File Locking Emacs used file locking to notice when two different users start to edit one file at the same time. See section Protection against Simultaneous Editing. File Name A file name is a name that refers to a file. File names may be relative or absolute; the meaning of a relative file name depends on the current directory, but an absolute file name refers to the same file regardless of which directory is current. On GNU and Unix systems, an absolute file name starts with a slash (the root directory) or with `~/' or `~user/' (a home directory). Some people use the term "pathname" for file names, but we do not; we use the word "path" only in the term "search path" (q.v.). File-Name Component A file-name component names a file directly within a particular directory. On GNU and Unix systems, a file name is a sequence of file-name components, separated by slashes. For example, `foo/bar' is a file name containing two components, `foo' and `bar'; it refers to the file named `bar' in the directory named `foo' in the current directory. Fill Prefix The fill prefix is a string that should be expected at the beginning of each line when filling is done. It is not regarded as part of the text to be filled. See section Filling Text. Filling Filling text means shifting text between consecutive lines so that all the lines are approximately the same length. See section Filling Text. Formatted Text Formatted text is text that displays with formatting information while you edit. Formatting information includes fonts, colors, and specified margins. See section Editing Formatted Text. Frame A frame is a rectangular cluster of Emacs windows. Emacs starts out with one frame, but you can create more. You can subdivide each frame into Emacs windows (q.v.). When you are using X windows, all the frames can be visible at the same time. See section Frames and X Windows. Function Key A function key is a key on the keyboard that sends input but does not correspond to any character. See section Rebinding Function Keys. Global Global means `independent of the current environment; in effect throughout Emacs'. It is the opposite of local (q.v.). Particular examples of the use of `global' appear below. Global Abbrev A global definition of an abbrev (q.v.) is effective in all major modes that do not have local (q.v.) definitions for the same abbrev. See section Abbrevs. Global Keymap The global keymap (q.v.) contains key bindings that are in effect except when overridden by local key bindings in a major mode's local keymap (q.v.). See section Keymaps. Global Mark Ring The global mark ring records the series of buffers you have recently set a mark in. In many cases you can use this to backtrack through buffers you have been editing in, or in which you have found tags. See section The Global Mark Ring. Global Substitution Global substitution means replacing each occurrence of one string by another string through a large amount of text. See section Replacement Commands. Global Variable The global value of a variable (q.v.) takes effect in all buffers that do not have their own local (q.v.) values for the variable. See section Variables. Graphic Character Graphic characters are those assigned pictorial images rather than just names. All the non-Meta (q.v.) characters except for the Control (q.v.) characters are graphic characters. These include letters, digits, punctuation, and spaces; they do not include RET or ESC. In Emacs, typing a graphic character inserts that character (in ordinary editing modes). See section Basic Editing Commands. Highlighting Highlighting text means displaying it with a different foreground and/or background color to make it stand out from the rest of the text in the buffer. Hardcopy Hardcopy means printed output. Emacs has commands for making printed listings of text in Emacs buffers. See section Hardcopy Output. HELP HELP is the Emacs name for C-h or F1. You can type HELP at any time to ask what options you have, or to ask what any command does. See section Help. Hyper Hyper is the name of a modifier bit which a keyboard input character may have. To make a character Hyper, type it while holding down the HYPER key. Such characters are given names that start with Hyper- (usually written H- for short). See section Kinds of User Input. Inbox An inbox is a file in which mail is delivered by the operating system. Rmail transfers mail from inboxes to Rmail files (q.v.) in which the mail is then stored permanently or until explicitly deleted. See section Rmail Files and Inboxes. Indentation Indentation means blank space at the beginning of a line. Most programming languages have conventions for using indentation to illuminate the structure of the program, and Emacs has special commands to adjust indentation. See section Indentation. Indirect Buffer An indirect buffer is a buffer that shares the text of another buffer, called its base buffer. See section Indirect Buffers. Input Event An input event represents, within Emacs, one action taken by the user on the terminal. Input events include typing characters, typing function keys, pressing or releasing mouse buttons, and switching between Emacs frames. See section Kinds of User Input. Input Method An input method is a system for entering non-ASCII text characters by typing sequences of ASCII characters (q.v.). See section Input Methods. Insertion Insertion means copying text into the buffer, either from the keyboard or from some other place in Emacs. Interlocking Interlocking is a feature for warning when you start to alter a file that someone else is already editing. See section Protection against Simultaneous Editing. Justification Justification means adding extra spaces to lines of text to make them come exactly to a specified width. See section Filling Text. Keyboard Macro Keyboard macros are a way of defining new Emacs commands from sequences of existing ones, with no need to write a Lisp program. See section Keyboard Macros. Key Sequence A key sequence (key, for short) is a sequence of input events (q.v.) that are meaningful as a single unit. If the key sequence is enough to specify one action, it is a complete key (q.v.); if it is not enough, it is a prefix key (q.v.). See section Keys. Keymap The keymap is the data structure that records the bindings (q.v.) of key sequences to the commands that they run. For example, the global keymap binds the character C-n to the command function next-line. See section Keymaps. Keyboard Translation Table The keyboard translation table is an array that translates the character codes that come from the terminal into the character codes that make up key sequences. See section Keyboard Translations. Kill Ring The kill ring is where all text you have killed recently is saved. You can reinsert any of the killed text still in the ring; this is called yanking (q.v.). See section Yanking. Killing Killing means erasing text and saving it on the kill ring so it can be yanked (q.v.) later. Some other systems call this "cutting." Most Emacs commands to erase text do killing, as opposed to deletion (q.v.). See section Deletion and Killing. Killing Jobs Killing a job (such as, an invocation of Emacs) means making it cease to exist. Any data within it, if not saved in a file, is lost. See section Exiting Emacs. Language Environment Your choice of language environment specifies defaults for the input method (q.v.) and coding system (q.v.). See section Language Environments. These defaults are relevant if you edit non-ASCII text (see section International Character Set Support). List A list is, approximately, a text string beginning with an open parenthesis and ending with the matching close parenthesis. In C mode and other non-Lisp modes, groupings surrounded by other kinds of matched delimiters appropriate to the language, such as braces, are also considered lists. Emacs has special commands for many operations on lists. See section Lists and Sexps. Local Local means `in effect only in a particular context'; the relevant kind of context is a particular function execution, a particular buffer, or a particular major mode. It is the opposite of `global' (q.v.). Specific uses of `local' in Emacs terminology appear below. Local Abbrev A local abbrev definition is effective only if a particular major mode is selected. In that major mode, it overrides any global definition for the same abbrev. See section Abbrevs. Local Keymap A local keymap is used in a particular major mode; the key bindings (q.v.) in the current local keymap override global bindings of the same key sequences. See section Keymaps. Local Variable A local value of a variable (q.v.) applies to only one buffer. See section Local Variables. M- M- in the name of a character is an abbreviation for META, one of the modifier keys that can accompany any character. See section Kinds of User Input. M-C- M-C- in the name of a character is an abbreviation for Control-Meta; it means the same thing as C-M-. If your terminal lacks a real META key, you type a Control-Meta character by typing ESC and then typing the corresponding Control character. See section Kinds of User Input. M-x M-x is the key sequence which is used to call an Emacs command by name. This is how you run commands that are not bound to key sequences. See section Running Commands by Name. Mail Mail means messages sent from one user to another through the computer system, to be read at the recipient's convenience. Emacs has commands for composing and sending mail, and for reading and editing the mail you have received. See section Sending Mail. See section Reading Mail with Rmail, for how to read mail. Mail Composition Method A mail composition method is a program runnable within Emacs for editing and sending a mail message. Emacs lets you select from several alternative mail composition methods. See section Mail-Composition Methods. Major Mode The Emacs major modes are a mutually exclusive set of options, each of which configures Emacs for editing a certain sort of text. Ideally, each programming language has its own major mode. See section Major Modes. Mark The mark points to a position in the text. It specifies one end of the region (q.v.), point being the other end. Many commands operate on all the text from point to the mark. Each buffer has its own mark. See section The Mark and the Region. Mark Ring The mark ring is used to hold several recent previous locations of the mark, just in case you want to move back to them. Each buffer has its own mark ring; in addition, there is a single global mark ring (q.v.). See section The Mark Ring. Menu Bar The menu bar is the line at the top of an Emacs frame. It contains words you can click on with the mouse to bring up menus. The menu bar feature is supported only with X. See section Menu Bars. Message See `mail'. Meta Meta is the name of a modifier bit which a command character may have. It is present in a character if the character is typed with the META key held down. Such characters are given names that start with Meta- (usually written M- for short). For example, M-< is typed by holding down META and at the same time typing < (which itself is done, on most terminals, by holding down SHIFT and typing ,). See section Kinds of User Input. Meta Character A Meta character is one whose character code includes the Meta bit. Minibuffer The minibuffer is the window that appears when necessary inside the echo area (q.v.), used for reading arguments to commands. See section The Minibuffer. Minibuffer History The minibuffer history records the text you have specified in the past for minibuffer arguments, so you can conveniently use the same text again. See section Minibuffer History. Minor Mode A minor mode is an optional feature of Emacs which can be switched on or off independently of all other features. Each minor mode has a command to turn it on or off. See section Minor Modes. Minor Mode Keymap A keymap that belongs to a minor mode and is active when that mode is enabled. Minor mode keymaps take precedence over the buffer's local keymap, just as the local keymap takes precedence over the global keymap. See section Keymaps. Mode Line The mode line is the line at the bottom of each window (q.v.), giving status information on the buffer displayed in that window. See section The Mode Line. Modified Buffer A buffer (q.v.) is modified if its text has been changed since the last time the buffer was saved (or since when it was created, if it has never been saved). See section Saving Files. Moving Text Moving text means erasing it from one place and inserting it in another. The usual way to move text by killing (q.v.) and then yanking (q.v.). See section Deletion and Killing. MULE MULE refers to the Emacs features for editing non-ASCII text using multibyte characters (q.v.). See section International Character Set Support. Multibyte Character A multibyte character is a character that takes up several buffer positions. Emacs uses multibyte characters to represent non-ASCII text, since the number of non-ASCII characters is much more than 256. See section Introduction to International Character Sets. Named Mark A named mark is a register (q.v.) in its role of recording a location in text so that you can move point to that location. See section Registers. Narrowing Narrowing means creating a restriction (q.v.) that limits editing in the current buffer to only a part of the text in the buffer. Text outside that part is inaccessible to the user until the boundaries are widened again, but it is still there, and saving the file saves it all. See section Narrowing. Newline Control-J characters in the buffer terminate lines of text and are therefore also called newlines. See section Character Set for Text. Numeric Argument A numeric argument is a number, specified before a command, to change the effect of the command. Often the numeric argument serves as a repeat count. See section Numeric Arguments. Overwrite Mode Overwrite mode is a minor mode. When it is enabled, ordinary text characters replace the existing text after point rather than pushing it to the right. See section Minor Modes. Page A page is a unit of text, delimited by formfeed characters (ASCII control-L, code 014) coming at the beginning of a line. Some Emacs commands are provided for moving over and operating on pages. See section Pages. Paragraph Paragraphs are the medium-size unit of English text. There are special Emacs commands for moving over and operating on paragraphs. See section Paragraphs. Parsing We say that certain Emacs commands parse words or expressions in the text being edited. Really, all they know how to do is find the other end of a word or expression. See section The Syntax Table. Point Point is the place in the buffer at which insertion and deletion occur. Point is considered to be between two characters, not at one character. The terminal's cursor (q.v.) indicates the location of point. See section Basic Editing Commands. Prefix Argument See `numeric argument'. Prefix Key A prefix key is a key sequence (q.v.) whose sole function is to introduce a set of longer key sequences. C-x is an example of prefix key; any two-character sequence starting with C-x is therefore a legitimate key sequence. See section Keys. Primary Rmail File Your primary Rmail file is the file named `RMAIL' in your home directory. That's where Rmail stores your incoming mail, unless you specify a different file name. See section Reading Mail with Rmail. Primary Selection The primary selection is one particular X selection (q.v.); it is the selection that most X applications use for transferring text to and from other applications. The Emacs kill commands set the primary selection and the yank command uses the primary selection when appropriate. See section Deletion and Killing. Prompt A prompt is text printed to ask the user for input. Displaying a prompt is called prompting. Emacs prompts always appear in the echo area (q.v.). One kind of prompting happens when the minibuffer is used to read an argument (see section The Minibuffer); the echoing which happens when you pause in the middle of typing a multi-character key sequence is also a kind of prompting (see section The Echo Area). Quitting Quitting means canceling a partially typed command or a running command, using C-g (or C-BREAK on MS-DOS). See section Quitting and Aborting. Quoting Quoting means depriving a character of its usual special significance. The most common kind of quoting in Emacs is with C-q. What constitutes special significance depends on the context and on convention. For example, an "ordinary" character as an Emacs command inserts itself; so in this context, a special character is any character that does not normally insert itself (such as DEL, for example), and quoting it makes it insert itself as if it were not special. Not all contexts allow quoting. See section Basic Editing Commands. Quoting File Names Quoting a file name turns off the special significance of constructs such as `$', `~' and `:'. See section Quoted File Names. Read-Only Buffer A read-only buffer is one whose text you are not allowed to change. Normally Emacs makes buffers read-only when they contain text which has a special significance to Emacs; for example, Dired buffers. Visiting a file that is write-protected also makes a read-only buffer. See section Using Multiple Buffers. Rectangle A rectangle consists of the text in a given range of columns on a given range of lines. Normally you specify a rectangle by putting point at one corner and putting the mark at the opposite corner. See section Rectangles. Recursive Editing Level A recursive editing level is a state in which part of the execution of a command involves asking the user to edit some text. This text may or may not be the same as the text to which the command was applied. The mode line indicates recursive editing levels with square brackets (`[' and `]'). See section Recursive Editing Levels. Redisplay Redisplay is the process of correcting the image on the screen to correspond to changes that have been made in the text being edited. See section The Organization of the Screen. Regexp See `regular expression'. Region The region is the text between point (q.v.) and the mark (q.v.). Many commands operate on the text of the region. See section The Mark and the Region. Registers Registers are named slots in which text or buffer positions or rectangles can be saved for later use. See section Registers. Regular Expression A regular expression is a pattern that can match various text strings; for example, `l[0-9]+' matches `l' followed by one or more digits. See section Syntax of Regular Expressions. Repeat Count See `numeric argument'. Replacement See `global substitution'. Restriction A buffer's restriction is the amount of text, at the beginning or the end of the buffer, that is temporarily inaccessible. Giving a buffer a nonzero amount of restriction is called narrowing (q.v.). See section Narrowing. RET RET is a character that in Emacs runs the command to insert a newline into the text. It is also used to terminate most arguments read in the minibuffer (q.v.). See section Kinds of User Input. Rmail File An Rmail file is a file containing text in a special format used by Rmail for storing mail. See section Reading Mail with Rmail. Saving Saving a buffer means copying its text into the file that was visited (q.v.) in that buffer. This is the way text in files actually gets changed by your Emacs editing. See section Saving Files. Scroll Bar A scroll bar is a tall thin hollow box that appears at the side of a window. You can use mouse commands in the scroll bar to scroll the window. The scroll bar feature is supported only with X. See section Scroll Bars. Scrolling Scrolling means shifting the text in the Emacs window so as to see a different part of the buffer. See section Controlling the Display. Searching Searching means moving point to the next occurrence of a specified string or the next match for a specified regular expression. See section Searching and Replacement. Search Path A search path is a list of directory names, to be used for searching for files for certain purposes. For example, the variable load-path holds a search path for finding Lisp library files. See section Libraries of Lisp Code for Emacs. Secondary Selection The secondary selection is one particular X selection; some X applications can use it for transferring text to and from other applications. Emacs has special mouse commands for transferring text using the secondary selection. See section Secondary Selection. Selecting Selecting a buffer means making it the current (q.v.) buffer. See section Using Multiple Buffers. Selection The X window system allows an application program to specify named selections whose values are text. A program can also read the selections that other programs have set up. This is the principal way of transferring text between window applications. Emacs has commands to work with the primary (q.v.) selection and the secondary (q.v.) selection. Self-Documentation Self-documentation is the feature of Emacs which can tell you what any command does, or give you a list of all commands related to a topic you specify. You ask for self-documentation with the help character, C-h. See section Help. Self-Inserting Character A character is self-inserting if typing that character inserts that character in the buffer. Ordinary printing and whitespace characters are self-inserting in Emacs, except in certain special major modes. Sentences Emacs has commands for moving by or killing by sentences. See section Sentences. Sexp A sexp (short for `s-expression') is the basic syntactic unit of Lisp in its textual form: either a list, or Lisp atom. Many Emacs commands operate on sexps. The term `sexp' is generalized to languages other than Lisp, to mean a syntactically recognizable expression. See section Lists and Sexps. Simultaneous Editing Simultaneous editing means two users modifying the same file at once. Simultaneous editing if not detected can cause one user to lose his work. Emacs detects all cases of simultaneous editing and warns one of the users to investigate. See section Protection against Simultaneous Editing. String A string is a kind of Lisp data object which contains a sequence of characters. Many Emacs variables are intended to have strings as values. The Lisp syntax for a string consists of the characters in the string with a `"' before and another `"' after. A `"' that is part of the string must be written as `\"' and a `\' that is part of the string must be written as `\\'. All other characters, including newline, can be included just by writing them inside the string; however, backslash sequences as in C, such as `\n' for newline or `\241' using an octal character code, are allowed as well. String Substitution See `global substitution'. Syntax Table The syntax table tells Emacs which characters are part of a word, which characters balance each other like parentheses, etc. See section The Syntax Table. Super Super is the name of a modifier bit which a keyboard input character may have. To make a character Super, type it while holding down the SUPER key. Such characters are given names that start with Super- (usually written s- for short). See section Kinds of User Input. Tags Table A tags table is a file that serves as an index to the function definitions in one or more other files. See section Tags Tables. Termscript File A termscript file contains a record of all characters sent by Emacs to the terminal. It is used for tracking down bugs in Emacs redisplay. Emacs does not make a termscript file unless you tell it to. See section Reporting Bugs. Text Two meanings (see section Commands for Human Languages): + Data consisting of a sequence of characters, as opposed to binary numbers, images, graphics commands, executable programs, and the like. The contents of an Emacs buffer are always text in this sense. + Data consisting of written human language, as opposed to programs, or following the stylistic conventions of human language. Top Level Top level is the normal state of Emacs, in which you are editing the text of the file you have visited. You are at top level whenever you are not in a recursive editing level (q.v.) or the minibuffer (q.v.), and not in the middle of a command. You can get back to top level by aborting (q.v.) and quitting (q.v.). See section Quitting and Aborting. Transposition Transposing two units of text means putting each one into the place formerly occupied by the other. There are Emacs commands to transpose two adjacent characters, words, sexps (q.v.) or lines (see section Transposing Text). Truncation Truncating text lines in the display means leaving out any text on a line that does not fit within the right margin of the window displaying it. See also `continuation line'. See section Basic Editing Commands. Undoing Undoing means making your previous editing go in reverse, bringing back the text that existed earlier in the editing session. See section Undoing Changes. User Option A user option is a variable (q.v.) that exists so that you can customize Emacs by setting it to a new value. See section Variables. Variable A variable is an object in Lisp that can store an arbitrary value. Emacs uses some variables for internal purposes, and has others (known as `user options' (q.v.)) just so that you can set their values to control the behavior of Emacs. The variables used in Emacs that you are likely to be interested in are listed in the Variables Index in this manual. See section Variables, for information on variables. Version Control Version control systems keep track of multiple versions of a source file. They provide a more powerful alternative to keeping backup files (q.v.). See section Version Control. Visiting Visiting a file means loading its contents into a buffer (q.v.) where they can be edited. See section Visiting Files. Whitespace Whitespace is any run of consecutive formatting characters (space, tab, newline, and backspace). Widening Widening is removing any restriction (q.v.) on the current buffer; it is the opposite of narrowing (q.v.). See section Narrowing. Window Emacs divides a frame (q.v.) into one or more windows, each of which can display the contents of one buffer (q.v.) at any time. See section The Organization of the Screen, for basic information on how Emacs uses the screen. See section Multiple Windows, for commands to control the use of windows. Word Abbrev Synonymous with `abbrev'. Word Search Word search is searching for a sequence of words, considering the punctuation between them as insignificant. See section Word Search. WYSIWYG WYSIWYG stands for `What you see is what you get.' Emacs generally provides WYSIWYG editing for files of characters; in Enriched mode (see section Editing Formatted Text), it provides WYSIWYG editing for files that include text formatting information. Yanking Yanking means reinserting text previously killed. It can be used to undo a mistaken kill, or for copying or moving text. Some other systems call this "pasting." See section Yanking. This document was generated on 6 November 1998 using the texi2html translator version 1.52.