This is Info file ../info/emacs, produced by Makeinfo-1.54 from the input file emacs.texi.  File: emacs, Node: General Variables, Next: Misc Variables, Up: Environment General Variables ----------------- `AUTHORCOPY' The name of a file used to archive news articles posted with the GNUS package. `CDPATH' Used by the `cd' command. `DOMAINNAME' The name of the internet domain that the machine running Emacs is located in. Used by the GNUS package. `EMACSDATA' Used to initialize the variable `data-directory' used to locate the architecture-independent files that come with Emacs. Setting this variable overrides the setting in `paths.h' when Emacs was built. `EMACSLOADPATH' A colon-separated list of directories from which to load Emacs Lisp files. Setting this variable overrides the setting in `paths.h' when Emacs was built. `EMACSLOCKDIR' The directory that Emacs places lock files--files used to protect users from editing the same files simultaneously. Setting this variable overrides the setting in `paths.h' when Emacs was built. `EMACSPATH' The location of Emacs-specific binaries. Setting this variable overrides the setting in `paths.h' when Emacs was built. `ESHELL' Used for shell-mode to override the `SHELL' environment variable. `HISTFILE' The name of the file that shell commands are saved in between logins. This variable defaults to `~/.history' if you use (t)csh as shell, to `~/.bash_history' if you use bash, to `~/.sh_history' if you use ksh, and to `~/.history' otherwise. `HOME' The location of the user's files in the directory tree; used for expansion of file names starting with a tilde (`~'). On MS-DOS, it defaults to the directory from which Emacs was started, with `/bin' removed from the end if it was present. `HOSTNAME' The name of the machine that Emacs is running on. `INCPATH' A colon-separated list of directories. Used by the `complete' package to search for files. `INFOPATH' A colon separated list of directories holding info files. Setting this variable overrides the setting in `paths.el' when Emacs was built. `LOGNAME' The user's login name. See also `USER'. `MAIL' The name of the user's system mail box. `MAILRC' Name of file containing mail aliases. This defaults to `~/.mailrc'. `MH' Name of setup file for the mh system. This defaults to `~/.mh_profile'. `NAME' The real-world name of the user. `NNTPSERVER' The name of the news server. Used by the mh and GNUS packages. `ORGANIZATION' The name of the organization to which you belong. Used for setting the `Organization:' header in your posts from the GNUS package. `PATH' A colon-separated list of directories in which executables reside. (On MS-DOS, it is semicolon-separated instead.) This variable is used to set the Emacs Lisp variable `exec-path' which you should consider to use instead. `PWD' If set, this should be the default directory when Emacs was started. `SAVEDIR' The name of a directory in which news articles are saved by default. Used by the GNUS package. `SHELL' The name of an interpreter used to parse and execute programs run from inside Emacs. `TERM' The name of the terminal that Emacs is running on. The variable must be set unless Emacs is run in batch mode. On MS-DOS, it defaults to `internal', which specifies a built-in terminal emulation that handles the machine's own display. `TERMCAP' The name of the termcap library file describing how to program the terminal specified by the `TERM' variable. This defaults to `/etc/termcap'. `TMPDIR' Used by the Emerge package as a prefix for temporary files. `TZ' This specifies the current time zone and possibly also daylight savings information. On MS-DOS, the default is based on country code; see the file `msdos.c' for details. `USER' The user's login name. See also `LOGNAME'. On MS-DOS, this defaults to `root'. `VERSION_CONTROL' Used to initialize the `version-control' variable (*note Backup Names::.).  File: emacs, Node: Misc Variables, Prev: General Variables, Up: Environment Misc Variables -------------- These variables are used only on particular configurations: `COMSPEC' On MS-DOS, the name of the command interpreter to use. This is used to make a default value for the `SHELL' environment variable. `NAME' On MS-DOS, this variable defaults to the value of the `USER' variable. `TEMP' `TMP' On MS-DOS, these specify the name of the directory for storing temporary files in. `USE_DOMAIN_ACLS' Used for Apollo machines to enable access control lists. `WINDOW_GFX' Used when initializing the Sun windows system.  File: emacs, Node: Display X, Next: Font X, Prev: Environment, Up: Command Arguments Specifying the Display Name =========================== The environment variable `DISPLAY' tells all X clients, including Emacs, where to display their windows. Its value is set up by default in ordinary circumstances, when you start an X server and run jobs locally. Occasionally you may need to specify the display yourself; for example, if you do a remote login and want to run a client program remotely, displaying on your local screen. With Emacs, the main reason people change the default display is to let them log into another system, run Emacs on that system, but have the window displayed at their local terminal. You might need to use login to another system because the files you want to edit are there, or because the Emacs executable file you want to run is there. The syntax of the `DISPLAY' environment variable is `HOST:DISPLAY.SCREEN', where HOST is the host name of the X Window System server machine, DISPLAY is an arbitrarily-assigned number that distinguishes your server (X terminal) from other servers on the same machine, and SCREEN is a rarely-used field that allows an X server to control multiple terminal screens. The period and the SCREEN field are optional. If included, SCREEN is usually zero. For example, if your host is named `glasperle' and your server is the first (or perhaps the only) server listed in the configuration, your `DISPLAY' is `glasperle:0.0'. You can specify the display name explicitly when you run Emacs, either by changing the `DISPLAY' variable, or with the option `-d DISPLAY' or `-display DISPLAY'. These are initial options; they must come at the beginning of the command line. *Note Initial Options::. Here is an example: emacs -display glasperle:0 & You can inhibit the direct use of X with the `-nw' option. This is also an initial option. This option tells Emacs to display using ordinary ASCII on its controlling terminal. Sometimes, security arrangements prevent a program on a remote system from displaying on your local system. In this case, trying to run Emacs produces messages like this: Xlib: connection to "glasperle:0.0" refused by server You might be able to overcome this problem by using the `xhost' command on the local system to give permission for access from your remote machine.  File: emacs, Node: Font X, Next: Colors X, Prev: Display X, Up: Command Arguments Font Specification Options ========================== By default, Emacs displays text in the font named `9x15', which makes each character nine pixels wide and fifteen pixels high. You can specify a different font on your command line through the option `-fn NAME'. `-fn NAME' Use font NAME as the default font. `-font NAME' `-font' is an alias for `-fn'. Under X, each font has a long name which consists of eleven words or numbers, separated by dashes. Some fonts also have shorter nicknames--`9x15' is such a nickname. You can use either kind of name. You can use wild card patterns for the font name; then Emacs lets X choose one of the fonts that match the pattern. Here is an example, which happens to specify the font whose nickname is `6x13': emacs -fn "-misc-fixed-medium-r-semicondensed--13-*-*-*-c-60-iso8859-1" & You can also specify the font in your `.Xdefaults' file: emacs.font: -misc-fixed-medium-r-semicondensed--13-*-*-*-c-60-iso8859-1 A long font name has the following form: -MAKER-FAMILY-WEIGHT-SLANT-WIDTHTYPE-STYLE... ...-PIXELS-HEIGHT-HORIZ-VERT-SPACING-WIDTH-CHARSET FAMILY This is the name of the font family-for example, `courier'. WEIGHT This is normally `bold', `medium' or `light'. Other words may appear here in some font names. SLANT This is `r' (roman), `i' (italic), `o' (oblique), `ri' (reverse italic), or `ot' (other). WIDTHTYPE This is normally `condensed', `extended', `semicondensed' or `normal'. Other words may appear here in some font names. STYLE This is an optional additional style name. Usually it is empty--most long font names have two hyphens in a row at this point. PIXELS This is the font height, in pixels. HEIGHT This is the font height on the screen, measured in printer's points (approximately 1/72 of an inch), times ten. For a given vertical resolution, HEIGHT and PIXELS are proportional; therefore, it is common to specify just one of them and use `*' for the other. HORIZ This is the horizontal resolution, in pixels per inch, of the screen for which the font is intended. VERT This is the vertical resolution, in dots per inch, of the screen for which the font is intended. Normally the resolution of the fonts on your system is the right value for your screen; therefore, you normally specify `*' for this and HORIZ. SPACING This is `m' (monospace), `p' (proportional) or `c' (character cell). Emacs can use `m' and `c' fonts. WIDTH This is the average character width, in pixels, times ten. CHARSET This is the character set that the font depicts. Normally you should use `iso8859-1'. Use only fixed width fonts--that is, fonts in which all characters have the same width; Emacs cannot yet handle display properly for variable width fonts. Any font with `m' or `c' in the SPACING field of the long name is a fixed width font. Here's how to use the `xlsfonts' program to list all the fixed width fonts available on your system: xlsfonts -fn '*x*' xlsfonts -fn '*-*-*-*-*-*-*-*-*-*-*-m*' xlsfonts -fn '*-*-*-*-*-*-*-*-*-*-*-c*' To see what a particular font looks like, use the `xfd' command. For example: xfd -fn 6x13 displays the entire font `6x13'. While running Emacs, you can set the font of the current frame (*note Frame Parameters::.) or for a specific kind of text (*note Faces::.).  File: emacs, Node: Colors X, Next: Window Size X, Prev: Font X, Up: Command Arguments Window Color Options ==================== On a color display, you can specify which color to use for various parts of the Emacs display. To find out what colors are available on your system, look at the `/usr/lib/X11/rgb.txt' file. If you do not specify colors, the default for the background is white and the default for all other colors is black. On a monochrome (black and white) display, the foreground is black, the background is white, and the border is grey. Here is a list of the options for specifying colors: `-fg COLOR' Specify the foreground color. `-bg COLOR' Specify the background color. `-bd COLOR' Specify the color of the border of the X window. `-cr COLOR' Specify the color of the Emacs cursor which indicates where point is. `-ms COLOR' Specify the color for the mouse cursor when the mouse is in the Emacs window. `-r' Reverse video--swap the foreground and background colors. For example, to use a coral mouse cursor and a slate blue text cursor, enter: emacs -ms coral -cr 'slate blue' & You can reverse the foreground and background colors through the `-r' option or with the X resource `reverseVideo'.  File: emacs, Node: Window Size X, Next: Borders X, Prev: Colors X, Up: Command Arguments Options for Window Geometry =========================== The `-geometry' option controls the size and position of the initial Emacs frame. Here is the format for specifying the window geometry: `-geometry WIDTHxHEIGHT{+-}XOFFSET{+-}YOFFSET' Specify window size WIDTH and HEIGHT (measured in character columns and lines), and positions XOFFSET and YOFFSET (measured in pixels). A positive XOFFSET specifies the distance from the left side of the screen, a negative XOFFSET specifies the distance from the right side of the screen, a positive YOFFSET specifies the distance from the top of the screen, and a negative YOFFSET specifies the distance from the bottom of the screen. Emacs uses the same units as `xterm' does to interpret the geometry. The WIDTH and HEIGHT are measured in characters, so a large font creates a larger frame than a small font. The XOFFSET and YOFFSET are measured in pixels. Since the mode line and the echo area occupy the last 2 lines of the frame, the height of the initial text window is 2 less than the height specified in your geometry. In non-toolkit versions of Emacs, the menu bar also takes one line of the specified number. You do not have to specify all of the fields in the geometry specification. If you omit both XOFFSET and YOFFSET, the window manager decides where to put the Emacs frame, possibly by letting you place it with the mouse. For example, `164x55' specifies a window 164 columns wide, enough for two ordinary width windows side by side, and 55 lines tall. The default width for Emacs is 80 characters and the default height is 40 lines. You can omit either the width or the height or both. If you start the geometry with an integer, Emacs interprets it as the width. If you start with an `x' followed by an integer, Emacs interprets it as the height. Thus, `81' specifies just the width; `x45' specifies just the height. If you start with `+' or `-', that introduces an offset, which means both sizes are omitted. Thus, `-3' specifies the XOFFSET only. (If you give just one offset, it is always XOFFSET.) `+3-3' specifies both the XOFFSET and the YOFFSET, placing the frame near the bottom left of the screen. You can specify a default for any or all of the fields in `.Xdefaults' file, and then override selected fields through a `-geometry' option.  File: emacs, Node: Borders X, Next: Icons X, Prev: Window Size X, Up: Command Arguments Internal and External Borders ============================= An Emacs frame has an internal border and an external border. The internal border is an extra strip of the background color around all four edges of the frame. Emacs itself adds the internal border. The external border is added by the window manager outside the internal border; it may contain various boxes you can click on to move or iconify the window. `-ib WIDTH' Specify WIDTH as the width of the internal border. `-bw WIDTH' Specify WIDTH as the width of the main border. When you specify the size of the frame, that does not count the borders. The frame's position is measured from the outside edge of the external border. Use the `-ib N' option to specify an internal border N pixels wide. The default is 1. Use `-bw N' to specify the width of the external border (though the window manager may not pay attention to what you specify). The default width of the external border is 2.  File: emacs, Node: Icons X, Next: Resources X, Prev: Borders X, Up: Command Arguments Icons ===== Most window managers allow the user to "iconify" a frame, removing it from sight, and leaving a small, distinctive "icon" window in its place. Clicking on the icon window makes the frame itself appear again. If you have many clients running at once, you can avoid cluttering up the screen by iconifying most of the clients. `-i' `-itype' Use a picture of a gnu as the Emacs icon. `-iconic' Start Emacs in iconified state. The `-i' and `-itype' option tells Emacs to use an icon window containing a picture of the GNU gnu. If omitted, Emacs lets the window manager choose what sort of icon to use--usually just a small rectangle containing the frame's title. The `-iconic' option tells Emacs to begin running as an icon, rather than opening a frame right away. In this situation, the icon window provides only indication that Emacs has started; the usual text frame doesn't appear until you deiconify it.  File: emacs, Node: Resources X, Prev: Icons X, Up: Command Arguments X Resources =========== Programs running under the X Window System organize their user options under a hierarchy of classes and resources. You can specify default values for these options in your X resources file, usually named `~/.Xdefaults'. Each line in the file specifies a value for one option or for a collection of related options, for one program or for several programs (optionally even for all programs). Programs define named resources with particular meanings. They also define how to group resources into named classes. For instance, in Emacs, the `internalBorder' resource controls the width of the internal border, and the `borderWidth' resource controls the width of the external border. Both of these resources are part of the `BorderWidth' class. Case distinctions are significant in these names. In `~/.Xdefaults', you can specify a value for a single resource on one line, like this: emacs.borderWidth: 2 Or you can use a class name to specify the same value for all resources in that class. Here's an example: emacs.BorderWidth: 2 If you specify a value for a class, it becomes the default for all resources in that class. You can specify values for individual resources as well; these override the class value, for those particular resources. Thus, this example specifies 2 as the default width for all borders, but overrides this value with 4 for the external border: emacs.Borderwidth: 2 emacs.borderwidth: 4 The order in which the lines appear in the file does not matter. Also, command-line options always override the X resources file. The string `emacs' in the examples above is also a resource name. It actually represents the name of the executable file that you invoke to run Emacs. If Emacs is installed under a different name, it looks for resources under that name instead of `emacs'. When Emacs creates a new frame, it may or may not have a specified title. The frame title, if specified, appears in window decorations and icons as the name of the frame. It is also used (instead of the Emacs executable's name) to look up all the resources for that frame. The option `-name' specifies a frame title for the initial frame. Subsequent frames normally have no frame title, but Lisp programs can specify a title when they create frames. `-name NAME' Use NAME as the title of the initial frame. For consistency, `-name' also specifies the name to use for other resource values that do not belong to any particular frame. The resources that name Emacs invocations also belong to a class; its name is `Emacs'. To specify options for all Emacs jobs, no matter what name is used to run them, write `Emacs' instead of `emacs', like this: Emacs.BorderWidth: 2 Emacs.borderWidth: 4 You can specify a string of additional resource values for Emacs to use with the command line option `-xrm RESOURCES'. The text RESOURCES should have the same format that you would use inside a file of X resources. To include multiple resource specifications in DATA, put a newline between them, just as you would in a file. You can also use `#include "FILENAME"' to include a file full of resource specifications. Resource values specified with `-xrm' take precedence over all other resource specifications. The following table lists the resource names that designate options for Emacs, each with the class that it belongs to: `background' (class `Background') Background color name. `bitmapIcon' (class `BitmapIcon') Use a bitmap icon (a picture of a gnu) if `on', let the window manager choose an icon if `off'. `borderColor' (class `BorderColor') Color name for the external border. `borderWidth' (class `BorderWidth') Width in pixels of the external border. `cursorColor' (class `Foreground') Color name for text cursor (point). `font' (class `Font') Font name for text. `foreground' (class `Foreground') Color name for text. `geometry' (class `Geometry') Window size and position. Be careful not to specify this resource as `emacs*geometry', because that may affect individual menus as well as the Emacs frame itself. `iconName' (class `Title') Name to display in the icon. `internalBorder' (class `BorderWidth') Width in pixels of the internal border. `paneFont' (class `Font') Font name for menu pane titles, in non-toolkit versions of Emacs. `pointerColor' (class `Foreground') Color of the mouse cursor. `reverseVideo' (class `ReverseVideo') Switch foreground and background default colors if `on', use colors as specified if `off'. `selectionFont' (class `Font') Font name for pop-up menu items, in non-toolkit versions of Emacs. (Toolkit versions, use `emacs.shell.menu.popup.font' instead--see below.) `title' (class `Title') Name to display in the title bar of the initial Emacs frame. If the Emacs installed at your site was built to use an X toolkit, then the menu bar is a separate widget and has its own resources. Their names start with `shell.pane.menubar'; specify them like this: Emacs.shell.pane.menubar.RESOURCE: VALUE For example, to specify the font `8x16' for the menu bar items, write this: Emacs.shell.pane.menubar.font: 8x16 or, for short, like this: Emacs*menubar.font: 8x16 Resources for toolkit popup menus have `shell.menu.popup', in like fashion. For example, to specify the font `8x16' for the menu bar items, write this: Emacs.shell.menu.popup.font: 8x16 Here is a list of the specific resources for menu bars and popup menus: `font' Font for menu item text. `foreground' Color of the foreground. `background' Color of the background. `buttonForeground' In the menu bar, the color of the foreground for a selected item. `horizontalSpacing' Horizontal spacing in pixels between items. Default is 3. `verticalSpacing' Vertical spacing in pixels between items. Default is 1. `arrowSpacing' Horizontal spacing between the arrow (which indicates a submenu) and the associated text. Default is 10. `shadowThickness' Thickness of shadow line around the widget. Here are resources for controlling the appearance of particular faces (*note Faces::.): `FACE.attributeFont' Font for face FACE. `FACE.attributeForeground' Foreground color for face FACE. `FACE.attributeBackground' Background color for face FACE. `FACE.attributeUnderline' Underline flag for face FACE.  File: emacs, Node: Antinews, Next: MS-DOS, Prev: Command Arguments, Up: Top Emacs 18 Antinews ***************** For those users who live backwards in time, here is information about downgrading to Emacs version 18. We hope you will enjoy the greater simplicity that results from the absence of many Emacs 19 features. Packages Removed ================ To reduce the size of the distribution, we have eliminated numerous packages including GNUS, VC (version control), Hexl (for editing binary files), Edebug, Emerge, Mpuz, Spook, and Gomoku. Major modes removed in Emacs 18 include C++ mode, Awk mode, Icon mode, Asm mode, Makefile mode, Perl mode and SGML mode. The function `enable-flow-control' does not exist; see the file `PROBLEMS' in the Emacs distribution for directions for coping with flow control. The Calendar feature provided is a very simple one. All it can do is display three months, by default centered around the current month. If you give it a numeric argument, that specifies the number of months forward or back. Fundamental Changes =================== Auto save and garbage collection happen only while you are typing, never while you are idle. This is to make them more like affectionate pets. Think of them as cats that like to sit on your terminal only when you are working there. Transient Mark mode and Line Number mode are absent in Emacs 18. If you are an Emacs user, you are smart enough to keep track of the mark in your head, and you don't need line numbers because you can search for precisely the text you want. There are no menu bars or scroll bars; no faces, text properties or overlays. You can't use `Mouse-2' to select files or objects referred to in the buffer. There are no minibuffer history commands. There is only one frame, so the Emacs 19 `C-x 5' command series is meaningless. Instead, `C-x 5' in Emacs 18 splits the selected window horizontally (like `C-x 3' in Emacs 19). Another simplification in Emacs 18 is that all input events are characters. Function keys and arrow keys are represented as sequences of characters; the terminal-specific Emacs Lisp file for your terminal is responsible for defining them. Mouse buttons are defined by a special keymap, `mouse-map'. See the file `x-mouse.el' for how to bind mouse clicks. There is no support for European character sets such as ISO Latin-1. Character codes 128 and above always display using `\NNN' notation. For codes 0 through 31, you can choose between `\NNN' and `^C' by setting the variable `ctl-arrow'; but that is the only thing you can specify about how character codes should display. You can't refer to files on other machines using special "magic" file names. Instead, you must use the `ftp' library with commands such as `M-x ftp-find-file' and `M-x ftp-write-file'. Since automatic uncompression also uses magic file names, that too is gone. The character for terminating an incremental search is now ESC, not RET as in Emacs 19. If you type RET, that searches for a newline; thus, you can insert a newline in the search string just as you would insert it in the text. Key Binding Changes =================== The key for `backward-paragraph' is now `M-['. The key for `forward-paragraph' is now `M-]'. The command `repeat-complex-command' is now on `C-x ESC'. The register commands have different key bindings: `C-x /' `point-to-register' `C-x j' `jump-to-register' `C-x x' `copy-to-register' `C-x g' `insert-register' `C-x r' `copy-rectangle-to-register' The narrowing commands have also been moved: `C-x n' `narrow-to-region' `C-x p' `narrow-to-page' `C-x w' `widen' And the abbrev commands as well: `C-x C-a' `add-mode-abbrev' `C-x +' `add-global-abbrev' `C-x C-h' `inverse-add-mode-abbrev' `C-x -' `inverse-add-global-abbrev' `C-x `' `expand-abbrev' There are no key bindings for the rectangle commands. `C-x a' now runs the command `append-to-buffer'. The key bindings `C-x 4 r' and `C-x 4 C-o' do not exist. The help commands `C-h C-f', `C-h C-k' and `C-h p' do not exist in Emacs 18. The command `C-M-l' (`reposition-window') is absent. Likewise `C-M-r' (`isearch-backward-regexp'). The "two column" commands starting with `C-x 6' don't exist in Emacs 18. The TeX mode bindings of `C-c {' and `C-c }' have been moved to `M-{' and `M-}'. (These commands are `up-list' and `tex-insert-braces'; they are the TeX equivalents of `M-(' and `M-)'.) Incremental Search Changes ========================== As mentioned above, the character for terminating an incremental search is now ESC, not RET as in Emacs 19. If you type RET, that searches for a newline; thus, you can insert a newline in the search string just as you would insert it in the text. There is no ring of previous search strings in Emacs 18. You can reuse the most recent search string, but that's all. If `case-fold-search' is non-`nil', then incremental search is *always* case-insensitive. Typing an upper-case letter in the search string has no effect on this. Spaces in the incremental search string match only spaces. The meanings of the special search characters are no longer controlled by a keymap. Instead, particular variables named `search-...-char' specify the character that should have a particular function. For example, `C-s' repeats the search because the value of `search-repeat-char' is `?\C-s'. Editing Command Changes ======================= `C-n' (`next-line') does not check the variable `next-line-add-newlines'. The sexp commands such as `C-M-f' no longer know anything about comments, in modes such as Lisp mode where the end of a comment is the end of the line. They treat the text inside a comment as if it were actual code. If comments containing unbalanced parentheses cause trouble, you can use the commands `C-M-n' and `C-M-p', which do ignore comments. You can't store file names in registers, and there are no frame configurations at all. The command `M-x string-rectangle' does not exist either. The undo command in Emacs 18 is not careful about where to leave point when you undo a deletion. It ends up at one end or the other of the text just undeleted. You must be on the lookout for this, and move point appropriately. Kill commands do nothing useful in read-only buffers. They just beep. `M-z C' in Emacs 18 kills up to but not including the first occurrence of C. If C does not occur in the buffer after point, `M-z' kills the whole rest of the buffer. The function `erase-buffer' is not a command in Emacs 18. You can call it from a Lisp program, but not interactively. The motivation for this is to protect you from accidentally deleting (not killing) the entire text of a buffer that you want to keep. With subsequent changes in even earlier Emacs versions (such as version 18.54), you might be unable to undo the `erase-buffer'. `M-x fill-nonuniform-paragraphs' and Adaptive Fill mode do not exist. Other Brief Notes ================= The mode line displays `%%' for all read-only buffers, whether modified or not. The command `resize-minibuffer-mode' has been removed. If you want to change the size of the minibuffer, do it by hand. Outline mode exists only as a major mode, not as a minor mode. `M-!' (`shell-command') always runs the command synchronously, even if the command ends with `&'. Emacs 18 has no special mode for change log files. It is a good idea to use Indented Text mode, and specify 8 as the value of the variable `left-margin'. The command `M-x comment-region' does not exist. The command `M-x super-apropos' does not exist. `C-x q' (`kbd-macro-query') now uses `C-d' to terminate all iterations of the keyboard macro, rather than ESC. The `M-x setenv' command is missing in Emacs 18. `M-$' now uses the Unix spell program instead of the GNU program Ispell. If the word around point is a misspelling, it asks you for a replacement. To check spelling of larger units of text, use `M-x spell-region' or `M-x spell-buffer'. These commands check all words in the specified piece of text. For each word that is not correct, they ask you to specify a replacement, and then replace each occurrence. `M-x gdb' still exists in Emacs 18. `M-x dbx' exists, but is somewhat different (use `C-h m' to find the details). `M-x sdb' does not exist at all, but who wants to use SDB? In Buffer Menu mode, the commands `%' and `C-o' don't work in Emacs 18. The `v' command has been eliminated and merged with the `q' command, which now exits the buffer menu, displaying all the buffers that you have marked. The View commands (such as `M-x view-buffer' and `M-x view-file') now use recursive edits. When you exit viewing, the recursive edit returns to its caller. Emacs 18, like most programs, interprets command line options only when it is started-not later on. The variable to control whether files can set local variables is called `inhibit-local-variables'. A non-`nil' value means ask the user before obeying any local variables lists. The user option for controlling use of the `eval' local variable is now called `inhibit-local-eval'. A non-`nil' value means to ask the user before obeying any `eval' local variable. File Handling Changes ===================== As mentioned above, you can't refer to files on other machines using special "magic" file names. Instead, you must use the `ftp' library with commands such as `M-x ftp-find-file' and `M-x ftp-write-file'. When you run `M-x revert-buffer' with no numeric argument, if the buffer has an auto save file more recent that the visited file, `revert-buffer' asks whether to revert from the auto save file instead. When `C-x s' (`save-some-buffers') offers to save each buffer, you have only two choices: save it, or don't save it. `M-x recover-file' turns off Auto Save mode in the current buffer. To turn it on again, use `M-x auto-save-mode'. The command `M-x rename-uniquely' does not exist; instead, use `M-x rename-buffer' and try various names until you find one that isn't in use. Completion can make this easier. The directory name abbreviation feature is gone in Emacs 18. Emacs 18 has no idea of file truenames, and does not try to detect when you visit a file via a symbolic link. You should check manually when you visit a file, so as to edit it in the directory where it is actually stored. This way you can make sure that backup files and change log entries go in the proper directory. `M-x compare-windows' ignores any numeric argument and always considers case and whitespace differences significant. As for the other ways of comparing files, `M-x diff' and `M-x diff-backup', they don't exist at all. Mail Changes ============ `%' is now a word-component character in Mail mode. This is to be compatible with Text mode. The variable `mail-signature' is not meaningful; if you wish to insert your signature in a mail message, you must type `C-c C-w'. Mail aliases expand only when you send the message--never when you type them in. Rmail now gets new mail into your primary mail file from `~/mbox' as well as from your system inbox file. This is handy if you occasionally check your newest mail with the `mail' program; whatever you have looked at and saved with `mail' will be brought into Rmail the next time you run Rmail. The `e' command is now "expunge", just like `x'. To edit the current message, type `w', which works in Emacs 19 as well. If you type `e' meaning to edit, and it expunges instead--well, you shouldn't have deleted those messages if you still wanted them. The Rmail summary buffer is now much simpler. Only a few special commands are available there: `n', `p', and `j' for motion, `d' and `u' for deletion, and SPC and DEL for scrolling the message. To do anything else, you must go to the Rmail buffer. Also, changes in the Rmail buffer don't update the summary; to do that, you must make a new summary. The Rmail command `rmail-resend' (accessible via `f' with a numeric argument in Emacs 19) does not exist in Emacs 18. Neither does `rmail-retry-failure' (`M-m' in Emacs 19). The Rmail sorting features have been removed, so you can be sure the order you see is the order that the messages arrived. The `<' and `b' commands have been removed in Emacs 18. Likewise `C-M-t' (`rmail-summarize-by-topic') and `M-x unrmail'. Rmail in Emacs 18 is so good, that we can't imagine anyone who has tried it would ever wish to use another mail reader. You must use the `o' command for output to a Rmail file, and the `C-o' for output to a file in system mailbox format. The default output file for `o' is now always the last file that you used with `o'. The variable `rmail-output-file-alist' has no special meaning. Emacs 18 Rmail does not know anything about Content Length fields in messages. C Mode Changes ============== In C mode, the keys `M-a' and `M-e' now have their usual meanings: motion by sentences. This is useful while editing the comments in a C program, but not useful for editing code. We hope this will encourage you to write lots of comments. The commands `M-x c-up-conditional' and `M-x c-backslash-region' have been removed entirely in Emacs 18. Compilation Changes =================== `M-x compile' now has a much simpler and faster parser for error messages. However, it understands fewer different formats for error messages, and is not as easy to customize. There is no special mode for compilation buffers. When you select the compilation buffer itself, it is just ordinary text. Speaking of selecting the compilation buffer, you do need to do that from time to time to see whether the compilation has finished, because Emacs 18 does not display `Compiling' in the mode line to tell you the compilation is still going. Shell Mode Changes ================== Shell mode in Emacs 18 does nothing special for the keys TAB, `M-?', `C-d'. The commands `M-x dirs' and `M-x send-invisible' are also gone. The history commands `M-p' and so on are not available either; instead, use `C-c C-y' (`copy-last-shell-input'). This copies the previous bunch of shell input, and inserts it into the buffer before point. No final newline is inserted, and the input copied is not resubmitted until you type RET. Use `C-c C-d' to send an "end of file" to the shell process. Dired Changes ============= For simplicity, Dired in Emacs 18 supports just one kind of mark: the deletion flag, `D'. The Emacs 19 Dired commands for flagging files do work in Emacs 18, but all the other mark-related commands do not. The Dired subdirectory commands don't exist in Emacs 18. A Dired buffer can contain only one directory. In particular, this means that the variable `dired-listing-switches' must not contain the `R' option. (The `F' option is also not allowed.) The commands for using `find' with Dired have been removed for simplicity, also. Emacs 18 Dired provides the following commands for manipulating files immediately, and no others. All of these commands apply to the file listed on the current line. `c' Copies the file described on the current line. You must supply a file name to copy to, using the minibuffer. `f' Visits the file described on the current line. It is just like typing `C-x C-f' and supplying that file name. If the file on this line is a subdirectory, `f' actually causes Dired to be invoked on that subdirectory. `G' Change the group of the file described on the current line. `M' Change the file mode of the file described on the current line. `o' Like `f', but uses another window to display the file's buffer. The Dired buffer remains visible in the first window. This is like using `C-x 4 C-f' to visit the file. `O' Change the owner of the file described on the current line. (On most systems, you must be a superuser to do this.) `r' Renames the file described on the current line. You must supply a file name to rename to, using the minibuffer. `v' Views the file described on this line using `M-x view-file'. Viewing a file is like visiting it, but is slanted toward moving around in the file conveniently and does not allow changing the file.  File: emacs, Node: MS-DOS, Next: Manifesto, Prev: Antinews, Up: Top MS-DOS Issues ************* This section briefly describes the peculiarities of using Emacs under the MS-DOS "operating system" (also known as "MS-DOG"). 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. On MS-DOS, file names are case-insensitive and limited to eight characters, plus optionally a period and three more characters. Emacs does not know about this limitation; it is up to you to specify valid file names. Excess characters before or after the period are generally ignored. Display on MS-DOS in Emacs 19.26 does not support menus or multiple fonts. Support for multiple faces that specify different colors should be added in version 19.27. Emacs on MS-DOS does support a mouse (on the default terminal only). The mouse commands work as documented, aside from those that try to use menus. *Note Mouse Commands::. Because MS-DOS is a single-process "operating system", asynchronous subprocesses are not available. In particular, Shell mode and its derivatives do not work. Compilation under Emacs with `M-x compile' does work, but the compiler runs synchronously; you cannot do any more editing until the compilation finishes. 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.