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This is Info file ../info/emacs, produced by Makeinfo-1.47 from the input file emacs.tex. This file documents the GNU Emacs editor. Copyright (C) 1985, 1986, 1988 Richard M. Stallman. Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided also that the sections entitled "The GNU Manifesto", "Distribution" and "GNU General Public License" are included exactly as in the original, and provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Permission is granted to copy and distribute translations of this manual into another language, under the above conditions for modified versions, except that the sections entitled "The GNU Manifesto", "Distribution" and "GNU General Public License" may be included in a translation approved by the author instead of in the original English. File: emacs, Node: Windows, Next: Major Modes, Prev: Buffers, Up: Top Multiple Windows **************** Emacs can split the screen into two or many windows, which can display parts of different buffers, or different parts of one buffer. * Menu: * Basic Window:: Introduction to Emacs windows. * Split Window:: New windows are made by splitting existing windows. * Other Window:: Moving to another window or doing something to it. * Pop Up Window:: Finding a file or buffer in another window. * Change Window:: Deleting windows and changing their sizes. File: emacs, Node: Basic Window, Next: Split Window, Prev: Windows, Up: Windows Concepts of Emacs Windows ========================= When multiple windows are being displayed, each window has an Emacs buffer designated for display in it. The same buffer may appear in more than one window; if it does, any changes in its text are displayed in all the windows where it appears. But the windows showing the same buffer can show different parts of it, because each window has its own value of point. At any time, one of the windows is the "selected window"; the buffer this window is displaying is the current buffer. The terminal's cursor shows the location of point in this window. Each other window has a location of point as well, but since the terminal has only one cursor there is no way to show where those locations are. Commands to move point affect the value of point for the selected Emacs window only. They do not change the value of point in any other Emacs window, even one showing the same buffer. The same is true for commands such as `C-x b' to change the selected buffer in the selected window; they do not affect other windows at all. However, there are other commands such as `C-x 4 b' that select a different window and switch buffers in it. Also, all commands that display information in a window, including (for example) `C-h f' (`describe-function') and `C-x C-b' (`list-buffers'), work by switching buffers in a nonselected window without affecting the selected window. Each window has its own mode line, which displays the buffer name, modification status and major and minor modes of the buffer that is displayed in the window. *Note Mode Line::, for full details on the mode line. File: emacs, Node: Split Window, Next: Other Window, Prev: Basic Window, Up: Windows Splitting Windows ================= `C-x 2' Split the selected window into two windows, one above the other (`split-window-vertically'). `C-x 5' Split the selected window into two windows positioned side by side (`split-window-horizontally'). The command `C-x 2' (`split-window-vertically') breaks the selected window into two windows, one above the other. Both windows start out displaying the same buffer, with the same value of point. By default the two windows each get half the height of the window that was split; a numeric argument specifies how many lines to give to the top window. `C-x 5' (`split-window-horizontally') breaks the selected window into two side-by-side windows. A numeric argument specifies how many columns to give the one on the left. A line of vertical bars separates the two windows. Windows that are not the full width of the screen have mode lines, but they are truncated; also, they do not always appear in inverse video, because, the Emacs display routines have not been taught how to display a region of inverse video that is only part of a line on the screen. When a window is less than the full width, text lines too long to fit are frequent. Continuing all those lines might be confusing. The variable `truncate-partial-width-windows' can be set non-`nil' to force truncation in all windows less than the full width of the screen, independent of the buffer being displayed and its value for `truncate-lines'. *Note Continuation Lines::. Horizontal scrolling is often used in side-by-side windows. *Note Display::. File: emacs, Node: Other Window, Next: Pop Up Window, Prev: Split Window, Up: Windows Using Other Windows =================== `C-x o' Select another window (`other-window'). That is `o', not zero. `C-M-v' Scroll the next window (`scroll-other-window'). `M-x compare-windows' Find next place where the text in the selected window does not match the text in the next window. To select a different window, use `C-x o' (`other-window'). That is an `o', for `other', not a zero. When there are more than two windows, this command moves through all the windows in a cyclic order, generally top to bottom and left to right. From the rightmost and bottommost window, it goes back to the one at the upper left corner. A numeric argument means to move several steps in the cyclic order of windows. A negative argument moves around the cycle in the opposite order. When the minibuffer is active, the minibuffer is the last window in the cycle; you can switch from the minibuffer window to one of the other windows, and later switch back and finish supplying the minibuffer argument that is requested. *Note Minibuffer Edit::. The usual scrolling commands (*note Display::.) apply to the selected window only, but there is one command to scroll the next window. `C-M-v' (`scroll-other-window') scrolls the window that `C-x o' would select. It takes arguments, positive and negative, like `C-v'. The command `M-x compare-windows' compares the text in the current window with that in the next window. Comparison starts at point in each window. Point moves forward in each window, a character at a time in each window, until the next characters in the two windows are different. Then the command is finished. File: emacs, Node: Pop Up Window, Next: Change Window, Prev: Other Window, Up: Windows Displaying in Another Window ============================ `C-x 4' is a prefix key for commands that select another window (splitting the window if there is only one) and select a buffer in that window. Different `C-x 4' commands have different ways of finding the buffer to select. `C-x 4 b BUFNAME RET' Select buffer BUFNAME in another window. This runs `switch-to-buffer-other-window'. `C-x 4 f FILENAME RET' Visit file FILENAME and select its buffer in another window. This runs `find-file-other-window'. *Note Visiting::. `C-x 4 d DIRECTORY RET' Select a Dired buffer for directory DIRECTORY in another window. This runs `dired-other-window'. *Note Dired::. `C-x 4 m' Start composing a mail message in another window. This runs `mail-other-window', and its same-window version is `C-x m' (*note Sending Mail::.). `C-x 4 .' Find a tag in the current tag table in another window. This runs `find-tag-other-window', the multiple-window variant of `M-.' (*note Tags::.). File: emacs, Node: Change Window, Prev: Pop Up Window, Up: Windows Deleting and Rearranging Windows ================================ `C-x 0' Get rid of the selected window (`kill-window'). That is a zero. `C-x 1' Get rid of all windows except the selected one (`delete-other-windows'). `C-x ^' Make the selected window taller, at the expense of the other(s) (`enlarge-window'). `C-x }' Make the selected window wider (`enlarge-window-horizontally'). To delete a window, type `C-x 0' (`delete-window'). (That is a zero.) The space occupied by the deleted window is distributed among the other active windows (but not the minibuffer window, even if that is active at the time). Once a window is deleted, its attributes are forgotten; there is no automatic way to make another window of the same shape or showing the same buffer. But the buffer continues to exist, and you can select it in any window with `C-x b'. `C-x 1' (`delete-other-windows') is more powerful than `C-x 0'; it deletes all the windows except the selected one (and the minibuffer); the selected window expands to use the whole screen except for the echo area. To readjust the division of space among existing windows, use `C-x ^' (`enlarge-window'). It makes the currently selected window get one line bigger, or as many lines as is specified with a numeric argument. With a negative argument, it makes the selected window smaller. `C-x }' (`enlarge-window-horizontally') makes the selected window wider by the specified number of columns. The extra screen space given to a window comes from one of its neighbors, if that is possible; otherwise, all the competing windows are shrunk in the same proportion. If this makes any windows too small, those windows are deleted and their space is divided up. The minimum size is specified by the variables `window-min-height' and `window-min-width'. File: emacs, Node: Major Modes, Next: Indentation, Prev: Windows, Up: Top Major Modes *********** Emacs has many different "major modes", each of which customizes Emacs for editing text of a particular sort. The major modes are mutually exclusive, and each buffer has one major mode at any time. The mode line normally contains the name of the current major mode, in parentheses. *Note Mode Line::. The least specialized major mode is called "Fundamental mode". This mode has no mode-specific redefinitions or variable settings, so that each Emacs command behaves in its most general manner, and each option is in its default state. For editing any specific type of text, such as Lisp code or English text, you should switch to the appropriate major mode, such as Lisp mode or Text mode. Selecting a major mode changes the meanings of a few keys to become more specifically adapted to the language being edited. The ones which are changed frequently are TAB, DEL, and LFD. In addition, the commands which handle comments use the mode to determine how comments are to be delimited. Many major modes redefine the syntactical properties of characters appearing in the buffer. *Note Syntax::. The major modes fall into three major groups. Lisp mode (which has several variants), C mode and Muddle mode are for specific programming languages. Text mode, Nroff mode, TeX mode and Outline mode are for editing English text. The remaining major modes are not intended for use on users' files; they are used in buffers created for specific purposes by Emacs, such as Dired mode for buffers made by Dired (*note Dired::.), and Mail mode for buffers made by `C-x m' (*note Sending Mail::.), and Shell mode for buffers used for communicating with an inferior shell process (*note Interactive Shell::.). Most programming language major modes specify that only blank lines separate paragraphs. This is so that the paragraph commands remain useful. *Note Paragraphs::. They also cause Auto Fill mode to use the definition of TAB to indent the new lines it creates. This is because most lines in a program are usually indented. *Note Indentation::. * Menu: * Choosing Modes:: How major modes are specified or chosen. File: emacs, Node: Choosing Modes, Prev: Major Modes, Up: Major Modes How Major Modes are Chosen ========================== You can select a major mode explicitly for the current buffer, but most of the time Emacs determines which mode to use based on the file name or some text in the file. Explicit selection of a new major mode is done with a `M-x' command. From the name of a major mode, add `-mode' to get the name of a command to select that mode. Thus, you can enter Lisp mode by executing `M-x lisp-mode'. When you visit a file, Emacs usually chooses the right major mode based on the file's name. For example, files whose names end in `.c' are edited in C mode. The correspondence between file names and major mode is controlled by the variable `auto-mode-alist'. Its value is a list in which each element has the form (REGEXP . MODE-FUNCTION) For example, one element normally found in the list has the form `("\\.c$" . c-mode)', and it is responsible for selecting C mode for files whose names end in `.c'. (Note that `\\' is needed in Lisp syntax to include a `\' in the string, which is needed to suppress the special meaning of `.' in regexps.) The only practical way to change this variable is with Lisp code. You can specify which major mode should be used for editing a certain file by a special sort of text in the first nonblank line of the file. The mode name should appear in this line both preceded and followed by `-*-'. Other text may appear on the line as well. For example, ;-*-Lisp-*- tells Emacs to use Lisp mode. Note how the semicolon is used to make Lisp treat this line as a comment. Such an explicit specification overrides any defaulting based on the file name. Another format of mode specification is -*-Mode: MODENAME;-*- which allows other things besides the major mode name to be specified. However, Emacs does not look for anything except the mode name. The major mode can also be specified in a local variables list. *Note File Variables::. When a file is visited that does not specify a major mode to use, or when a new buffer is created with `C-x b', the major mode used is that specified by the variable `default-major-mode'. Normally this value is the symbol `fundamental-mode', which specifies Fundamental mode. If `default-major-mode' is `nil', the major mode is taken from the previously selected buffer. File: emacs, Node: Indentation, Next: Text, Prev: Major Modes, Up: Top Indentation *********** `TAB' Indent current line "appropriately" in a mode-dependent fashion. `LFD' Perform RET followed by TAB (`newline-and-indent'). `M-^' Merge two lines (`delete-indentation'). This would cancel out the effect of LFD. `C-M-o' Split line at point; text on the line after point becomes a new line indented to the same column that it now starts in (`split-line'). `M-m' Move (forward or back) to the first nonblank character on the current line (`back-to-indentation'). `C-M-\' Indent several lines to same column (`indent-region'). `C-x TAB' Shift block of lines rigidly right or left (`indent-rigidly'). `M-i' Indent from point to the next prespecified tab stop column (`tab-to-tab-stop'). `M-x indent-relative' Indent from point to under an indentation point in the previous line. Most programming languages have some indentation convention. For Lisp code, lines are indented according to their nesting in parentheses. The same general idea is used for C code, though many details are different. Whatever the language, to indent a line, use the TAB command. Each major mode defines this command to perform the sort of indentation appropriate for the particular language. In Lisp mode, TAB aligns the line according to its depth in parentheses. No matter where in the line you are when you type TAB, it aligns the line as a whole. In C mode, TAB implements a subtle and sophisticated indentation style that knows about many aspects of C syntax. In Text mode, TAB runs the command `tab-to-tab-stop', which indents to the next tab stop column. You can set the tab stops with `M-x edit-tab-stops'. * Menu: * Indentation Commands:: Various commands and techniques for indentation. * Tab Stops:: You can set arbitrary "tab stops" and then indent to the next tab stop when you want to. * Just Spaces:: You can request indentation using just spaces. File: emacs, Node: Indentation Commands, Next: Tab Stops, Prev: Indentation, Up: Indentation Indentation Commands and Techniques =================================== If you just want to insert a tab character in the buffer, you can type `C-q TAB'. To move over the indentation on a line, do `Meta-m' (`back-to-indentation'). This command, given anywhere on a line, positions point at the first nonblank character on the line. To insert an indented line before the current line, do `C-a C-o TAB'. To make an indented line after the current line, use `C-e LFD'. `C-M-o' (`split-line') moves the text from point to the end of the line vertically down, so that the current line becomes two lines. `C-M-o' first moves point forward over any spaces and tabs. Then it inserts after point a newline and enough indentation to reach the same column point is on. Point remains before the inserted newline; in this regard, `C-M-o' resembles `C-o'. To join two lines cleanly, use the `Meta-^' (`delete-indentation') command to delete the indentation at the front of the current line, and the line boundary as well. They are replaced by a single space, or by no space if at the beginning of a line or before a `)' or after a `('. To delete just the indentation of a line, go to the beginning of the line and use `Meta-\' (`delete-horizontal-space'), which deletes all spaces and tabs around the cursor. There are also commands for changing the indentation of several lines at once. `Control-Meta-\' (`indent-region') gives each line which begins in the region the "usual" indentation by invoking TAB at the beginning of the line. A numeric argument specifies the column to indent to, and each line is shifted left or right so that its first nonblank character appears in that column. `C-x TAB' (`indent-rigidly') moves all of the lines in the region right by its argument (left, for negative arguments). The whole group of lines moves rigidly sideways, which is how the command gets its name. `M-x indent-relative' indents at point based on the previous line (actually, the last nonempty line.) It inserts whitespace at point, moving point, until it is underneath an indentation point in the previous line. An indentation point is the end of a sequence of whitespace or the end of the line. If point is farther right than any indentation point in the previous line, the whitespace before point is deleted and the first indentation point then applicable is used. If no indentation point is applicable even then, `tab-to-tab-stop' is run (see next section). `indent-relative' is the definition of TAB in Indented Text mode. *Note Text::. File: emacs, Node: Tab Stops, Next: Just Spaces, Prev: Indentation Commands, Up: Indentation Tab Stops ========= For typing in tables, you can use Text mode's definition of TAB, `tab-to-tab-stop'. This command inserts indentation before point, enough to reach the next tab stop column. If you are not in Text mode, this function can be found on `M-i' anyway. The tab stops used by `M-i' can be set arbitrarily by the user. They are stored in a variable called `tab-stop-list', as a list of column-numbers in increasing order. The convenient way to set the tab stops is using `M-x edit-tab-stops', which creates and selects a buffer containing a description of the tab stop settings. You can edit this buffer to specify different tab stops, and then type `C-c C-c' to make those new tab stops take effect. In the tab stop buffer, `C-c C-c' runs the function `edit-tab-stops-note-changes' rather than its usual definition `save-buffer'. `edit-tab-stops' records which buffer was current when you invoked it, and stores the tab stops back in that buffer; normally all buffers share the same tab stops and changing them in one buffer affects all, but if you happen to make `tab-stop-list' local in one buffer then `edit-tab-stops' in that buffer will edit the local settings. Here is what the text representing the tab stops looks like for ordinary tab stops every eight columns. : : : : : : 0 1 2 3 4 0123456789012345678901234567890123456789012345678 To install changes, type C-c C-c The first line contains a colon at each tab stop. The remaining lines are present just to help you see where the colons are and know what to do. Note that the tab stops that control `tab-to-tab-stop' have nothing to do with displaying tab characters in the buffer. *Note Display Vars::, for more information on that. File: emacs, Node: Just Spaces, Prev: Tab Stops, Up: Indentation Tabs vs. Spaces =============== Emacs normally uses both tabs and spaces to indent lines. If you prefer, all indentation can be made from spaces only. To request this, set `indent-tabs-mode' to `nil'. This is a per-buffer variable; altering the variable affects only the current buffer, but there is a default value which you can change as well. *Note Locals::. There are also commands to convert tabs to spaces or vice versa, always preserving the columns of all nonblank text. `M-x tabify' scans the region for sequences of spaces, and converts sequences of at least three spaces to tabs if that can be done without changing indentation. `M-x untabify' changes all tabs in the region to appropriate numbers of spaces. File: emacs, Node: Text, Next: Programs, Prev: Indentation, Up: Top Commands for Human Languages **************************** The term "text" has two widespread meanings in our area of the computer field. One is data that is a sequence of characters. Any file that you edit with Emacs is text, in this sense of the word. The other meaning is more restrictive: a sequence of characters in a human language for humans to read (possibly after processing by a text formatter), as opposed to a program or commands for a program. Human languages have syntactic/stylistic conventions that can be supported or used to advantage by editor commands: conventions involving words, sentences, paragraphs, and capital letters. This chapter describes Emacs commands for all of these things. There are also commands for "filling", or rearranging paragraphs into lines of approximately equal length. The commands for moving over and killing words, sentences and paragraphs, while intended primarily for editing text, are also often useful for editing programs. Emacs has several major modes for editing human language text. If the file contains text pure and simple, use Text mode, which customizes Emacs in small ways for the syntactic conventions of text. For text which contains embedded commands for text formatters, Emacs has other major modes, each for a particular text formatter. Thus, for input to TeX, you would use TeX mode; for input to nroff, Nroff mode. * Menu: * Text Mode:: The major modes for editing text files. * Nroff Mode:: The major mode for editing input to the formatter nroff. * TeX Mode:: The major modes for editing input to the formatter TeX. * Outline Mode::The major mode for editing outlines. * Words:: Moving over and killing words. * Sentences:: Moving over and killing sentences. * Paragraphs:: Moving over paragraphs. * Pages:: Moving over pages. * Filling:: Filling or justifying text * Case:: Changing the case of text File: emacs, Node: Text Mode, Next: Words, Prev: Text, Up: Text Text Mode ========= Editing files of text in a human language ought to be done using Text mode rather than Lisp or Fundamental mode. Invoke `M-x text-mode' to enter Text mode. In Text mode, TAB runs the function `tab-to-tab-stop', which allows you to use arbitrary tab stops set with `M-x edit-tab-stops' (*note Tab Stops::.). Features concerned with comments in programs are turned off except when explicitly invoked. The syntax table is changed so that periods are not considered part of a word, while apostrophes, backspaces and underlines are. A similar variant mode is Indented Text mode, intended for editing text in which most lines are indented. This mode defines TAB to run `indent-relative' (*note Indentation::.), and makes Auto Fill indent the lines it creates. The result is that normally a line made by Auto Filling, or by LFD, is indented just like the previous line. Use `M-x indented-text-mode' to select this mode. Entering Text mode or Indented Text mode calls with no arguments the value of the variable `text-mode-hook', if that value exists and is not `nil'. This value is also called when modes related to Text mode are entered; this includes Nroff mode, TeX mode, Outline mode and Mail mode. Your hook can look at the value of `major-mode' to see which of these modes is actually being entered. * Menu: Two modes similar to Text mode are of use for editing text that is to be passed through a text formatter before achieving the form in which humans are to read it. * Nroff Mode:: The major mode for editing input to the formatter nroff. * TeX Mode:: The major modes for editing input to the formatter TeX. Another similar mode is used for editing outlines. It allows you to view the text at various levels of detail. You can view either the outline headings alone or both headings and text; you can also hide some of the headings at lower levels from view to make the high level structure more visible. * Outline Mode::The major mode for editing outlines. File: emacs, Node: Nroff Mode, Next: TeX Mode, Prev: Text Mode, Up: Text Mode Nroff Mode ---------- Nroff mode is a mode like Text mode but modified to handle nroff commands present in the text. Invoke `M-x nroff-mode' to enter this mode. It differs from Text mode in only a few ways. All nroff command lines are considered paragraph separators, so that filling will never garble the nroff commands. Pages are separated by `.bp' commands. Comments start with backslash-doublequote. Also, three special commands are provided that are not in Text mode: `M-n' Move to the beginning of the next line that isn't an nroff command (`forward-text-line'). An argument is a repeat count. `M-p' Like `M-n' but move up (`backward-text-line'). `M-?' Prints in the echo area the number of text lines (lines that are not nroff commands) in the region (`count-text-lines'). The other feature of Nroff mode is that you can turn on Electric Nroff newline mode. This is a minor mode that you can turn on or off with `M-x electric-nroff-mode' (*note Minor Modes::.). When the mode is on, each time you use RET to end a line that contains an nroff command that opens a kind of grouping, the matching nroff command to close that grouping is automatically inserted on the following line. For example, if you are at the beginning of a line and type `. ( b RET', the matching command `.)b' will be inserted on a new line following point. Entering Nroff mode calls with no arguments the value of the variable `text-mode-hook', if that value exists and is not `nil'; then it does the same with the variable `nroff-mode-hook'. File: emacs, Node: TeX Mode, Next: Outline Mode, Prev: Nroff Mode, Up: Text Mode TeX Mode -------- TeX is a powerful text formatter written by Donald Knuth; it is also free, like GNU Emacs. LaTeX is a simplified input format for TeX, implemented by TeX macros. It comes with TeX. Emacs has a special TeX mode for editing TeX input files. It provides facilities for checking the balance of delimiters and for invoking TeX on all or part of the file. TeX mode has two variants, Plain TeX mode and LaTeX mode (actually two distinct major modes which differ only slightly). They are designed for editing the two different input formats. The command `M-x tex-mode' looks at the contents of the buffer to determine whether the contents appear to be LaTeX input or not; it then selects the appropriate mode. If it can't tell which is right (e.g., the buffer is empty), the variable `TeX-default-mode' controls which mode is used. The commands `M-x plain-tex-mode' and `M-x latex-mode' explicitly select the two variants of TeX mode. Use these commands when `M-x tex-mode' does not guess right. * Menu: * Editing: TeX Editing. Special commands for editing in TeX mode. * Printing: TeX Print. Commands for printing part of a file with TeX. TeX for Unix systems can be obtained from the University of Washington for a distribution fee. To order a full distribution, send $140.00 for a 1/2 inch 9-track tape, $165.00 for two 4-track 1/4 inch cartridge tapes (foreign sites $150.00, for 1/2 inch, $175.00 for 1/4 inch, to cover the extra postage) payable to the University of Washington to: The Director Northwest Computer Support Group, DW-10 University of Washington Seattle, Washington 98195 Purchase orders are acceptable, but there is an extra charge of $10.00, to pay for processing charges. (Total of $150 for domestic sites, $175 for foreign sites). The normal distribution is a tar tape, blocked 20, 1600 bpi, on an industry standard 2400 foot half-inch reel. The physical format for the 1/4 inch streamer cartridges uses QIC-11, 8000 bpi, 4-track serpentine recording for the SUN. Also, SystemV tapes can be written in cpio format, blocked 5120 bytes, ASCII headers. File: emacs, Node: TeX Editing, Next: TeX Print, Prev: TeX Mode, Up: TeX Mode TeX Editing Commands .................... Here are the special commands provided in TeX mode for editing the text of the file. `"' Insert, according to context, either ```' or `"' or `''' (`TeX-insert-quote'). `LFD' Insert a paragraph break (two newlines) and check the previous paragraph for unbalanced braces or dollar signs (`TeX-terminate-paragraph'). `M-x validate-TeX-buffer' Check each paragraph in the buffer for unbalanced braces or dollar signs. `M-{' Insert `{}' and position point between them (`TeX-insert-braces'). `M-}' Move forward past the next unmatched close brace (`up-list'). `C-c C-f' Close a block for LaTeX (`TeX-close-LaTeX-block'). In TeX, the character `"' is not normally used; one uses ```' to start a quotation and `''' to end one. TeX mode defines the key `"' to insert ```' after whitespace or an open brace, `"' after a backslash, or `''' otherwise. This is done by the command `TeX-insert-quote'. If you need the character `"' itself in unusual contexts, use `C-q' to insert it. Also, `"' with a numeric argument always inserts that number of `"' characters. In TeX mode, `$' has a special syntax code which attempts to understand the way TeX math mode delimiters match. When you insert a `$' that is meant to exit math mode, the position of the matching `$' that entered math mode is displayed for a second. This is the same feature that displays the open brace that matches a close brace that is inserted. However, there is no way to tell whether a `$' enters math mode or leaves it; so when you insert a `$' that enters math mode, the previous `$' position is shown as if it were a match, even though they are actually unrelated. If you prefer to keep braces balanced at all times, you can use `M-{' (`TeX-insert-braces') to insert a pair of braces. It leaves point between the two braces so you can insert the text that belongs inside. Afterward, use the command `M-}' (`up-list') to move forward past the close brace. There are two commands for checking the matching of braces. LFD (`TeX-terminate-paragraph') checks the paragraph before point, and inserts two newlines to start a new paragraph. It prints a message in the echo area if any mismatch is found. `M-x validate-TeX-buffer' checks the entire buffer, paragraph by paragraph. When it finds a paragraph that contains a mismatch, it displays point at the beginning of the paragraph for a few seconds and pushes a mark at that spot. Scanning continues until the whole buffer has been checked or until you type another key. The positions of the last several paragraphs with mismatches can be found in the mark ring (*note Mark Ring::.). Note that square brackets and parentheses are matched in TeX mode, not just braces. This is wrong for the purpose of checking TeX syntax. However, parentheses and square brackets are likely to be used in text as matching delimiters and it is useful for the various motion commands and automatic match display to work with them. In LaTeX input, `\begin' and `\end' commands must balance. After you insert a `\begin', use `C-c C-f' (`TeX-close-LaTeX-block') to insert automatically a matching `\end' (on a new line following the `\begin'). A blank line is inserted between the two, and point is left there. File: emacs, Node: TeX Print, Prev: TeX Editing, Up: TeX Mode TeX Printing Commands ..................... You can invoke TeX as an inferior of Emacs on either the entire contents of the buffer or just a region at a time. Running TeX in this way on just one chapter is a good way to see what your changes look like without taking the time to format the entire file. `C-c C-r' Invoke TeX on the current region, plus the buffer's header (`TeX-region'). `C-c C-b' Invoke TeX on the entire current buffer (`TeX-buffer'). `C-c C-l' Recenter the window showing output from the inferior TeX so that the last line can be seen (`TeX-recenter-output-buffer'). `C-c C-k' Kill the inferior TeX (`TeX-kill-job'). `C-c C-p' Print the output from the last `C-c C-r' or `C-c C-b' command (`TeX-print'). `C-c C-q' Show the printer queue (`TeX-show-print-queue'). You can pass the current buffer through an inferior TeX by means of `C-c C-b' (`TeX-buffer'). The formatted output appears in a file in `/tmp'; to print it, type `C-c C-p' (`TeX-print'). Afterward use `C-c C-q' (`TeX-show-print-queue') to view the progress of your output towards being printed. The console output from TeX, including any error messages, appear in a buffer called `*TeX-shell*'. If TeX gets an error, you can switch to this buffer and feed it input (this works as in Shell mode; *note Interactive Shell::.). Without switching to this buffer you can scroll it so that its last line is visible by typing `C-c C-l'. Type `C-c C-k' (`TeX-kill-job') to kill the TeX process if you see that its output is no longer useful. Using `C-c C-b' or `C-c C-r' also kills any TeX process still running. You can also pass an arbitrary region through an inferior TeX by typing `C-c C-r' (`TeX-region'). This is tricky, however, because most files of TeX input contain commands at the beginning to set parameters and define macros, without which no later part of the file will format correctly. To solve this problem, `C-c C-r' allows you to designate a part of the file as containing essential commands; it is included before the specified region as part of the input to TeX. The designated part of the file is called the "header". To indicate the bounds of the header in Plain TeX mode, you insert two special strings in the file. Insert `%**start of header' before the header, and `%**end of header' after it. Each string must appear entirely on one line, but there may be other text on the line before or after. The lines containing the two strings are included in the header. If `%**start of header' does not appear within the first 100 lines of the buffer, `C-c C-r' assumes that there is no header. In LaTeX mode, the header begins with `\documentstyle' and ends with `\begin{document}'. These are commands that LaTeX requires you to use in any case, so nothing special needs to be done to identify the header. Entering either kind of TeX mode calls with no arguments the value of the variable `text-mode-hook', if that value exists and is not `nil'; then it does the same with the variable `TeX-mode-hook'. Finally it does the same with either `plain-TeX-mode-hook' or `LaTeX-mode-hook'. File: emacs, Node: Outline Mode, Prev: TeX Mode, Up: Text Mode Outline Mode ------------ Outline mode is a major mode much like Text mode but intended for editing outlines. It allows you to make parts of the text temporarily invisible so that you can see just the overall structure of the outline. Type `M-x outline-mode' to turn on Outline mode in the current buffer. Entering Outline mode calls with no arguments the value of the variable `text-mode-hook', if that value exists and is not `nil'; then it does the same with the variable `outline-mode-hook'. When a line is invisible in outline mode, it does not appear on the screen. The screen appears exactly as if the invisible line were deleted, except that an ellipsis (three periods in a row) appears at the end of the previous visible line (only one ellipsis no matter how many invisible lines follow). All editing commands treat the text of the invisible line as part of the previous visible line. For example, `C-n' moves onto the next visible line. Killing an entire visible line, including its terminating newline, really kills all the following invisible lines along with it; yanking it all back yanks the invisible lines and they remain invisible. * Menu: * Format: Outline Format. What the text of an outline looks like. * Motion: Outline Motion. Special commands for moving through outlines. * Visibility: Outline Visibility. Commands to control what is visible. File: emacs, Node: Outline Format, Next: Outline Motion, Prev: Outline Mode, Up: Outline Mode Format of Outlines .................. Outline mode assumes that the lines in the buffer are of two types: "heading lines" and "body lines". A heading line represents a topic in the outline. Heading lines start with one or more stars; the number of stars determines the depth of the heading in the outline structure. Thus, a heading line with one star is a major topic; all the heading lines with two stars between it and the next one-star heading are its subtopics; and so on. Any line that is not a heading line is a body line. Body lines belong to the preceding heading line. Here is an example: * Food This is the body, which says something about the topic of food. ** Delicious Food This is the body of the second-level header. ** Distasteful Food This could have a body too, with several lines. *** Dormitory Food * Shelter A second first-level topic with its header line. A heading line together with all following body lines is called collectively an "entry". A heading line together with all following deeper heading lines and their body lines is called a "subtree". You can customize the criterion for distinguishing heading lines by setting the variable `outline-regexp'. Any line whose beginning has a match for this regexp is considered a heading line. Matches that start within a line (not at the beginning) do not count. The length of the matching text determines the level of the heading; longer matches make a more deeply nested level. Thus, for example, if a text formatter has commands `@chapter', `@section' and `@subsection' to divide the document into chapters and sections, you could make those lines count as heading lines by setting `outline-regexp' to `"@chap\\|@\$sub\$*section"'. Note the trick: the two words `chapter' and `section' are equally long, but by defining the regexp to match only `chap' we ensure that the length of the text matched on a chapter heading is shorter, so that Outline mode will know that sections are contained in chapters. This works as long as no other command starts with `@chap'. Outline mode makes a line invisible by changing the newline before it into an ASCII Control-M (code 015). Most editing commands that work on lines treat an invisible line as part of the previous line because, strictly speaking, it is part of that line, since there is no longer a newline in between. When you save the file in Outline mode, Control-M characters are saved as newlines, so the invisible lines become ordinary lines in the file. But saving does not change the visibility status of a line inside Emacs. File: emacs, Node: Outline Motion, Next: Outline Visibility, Prev: Outline Format, Up: Outline Mode Outline Motion Commands ....................... There are some special motion commands in Outline mode that move backward and forward to heading lines. `C-c C-n' Move point to the next visible heading line (`outline-next-visible-heading'). `C-c C-p' Move point to the previous visible heading line (`outline-previous-visible-heading'). `C-c C-f' Move point to the next visible heading line at the same level as the one point is on (`outline-forward-same-level'). `C-c C-b' Move point to the previous visible heading line at the same level (`outline-backward-same-level'). `C-c C-u' Move point up to a lower-level (more inclusive) visible heading line (`outline-up-heading'). `C-c C-n' (`next-visible-heading') moves down to the next heading line. `C-c C-p' (`previous-visible-heading') moves similarly backward. Both accept numeric arguments as repeat counts. The names emphasize that invisible headings are skipped, but this is not really a special feature. All editing commands that look for lines ignore the invisible lines automatically. More advanced motion commands understand the levels of headings. The commands `C-c C-f' (`outline-forward-same-level') and `C-c C-b' (`outline-backward-same-level') move from one heading line to another visible heading at the same depth in the outline. `C-c C-u' (`outline-up-heading') moves backward to another heading that is less deeply nested. File: emacs, Node: Outline Visibility, Prev: Outline Motion, Up: Outline Mode Outline Visibility Commands ........................... The other special commands of outline mode are used to make lines visible or invisible. Their names all start with `hide' or `show'. Most of them fall into pairs of opposites. They are not undoable; instead, you can undo right past them. Making lines visible or invisible is simply not recorded by the undo mechanism. `M-x hide-body' Make all body lines in the buffer invisible. `M-x show-all' Make all lines in the buffer visible. `C-c C-h' Make everything under this heading invisible, not including this heading itself (`hide-subtree'). `C-c C-s' Make everything under this heading visible, including body, subheadings, and their bodies (`show-subtree'). `M-x hide-leaves' Make the body of this heading line, and of all its subheadings, invisible. `M-x show-branches' Make all subheadings of this heading line, at all levels, visible. `C-c C-i' Make immediate subheadings (one level down) of this heading line visible (`show-children'). `M-x hide-entry' Make this heading line's body invisible. `M-x show-entry' Make this heading line's body visible. Two commands that are exact opposites are `M-x hide-entry' and `M-x show-entry'. They are used with point on a heading line, and apply only to the body lines of that heading. The subtopics and their bodies are not affected. Two more powerful opposites are `C-c C-h' (`hide-subtree') and `C-c C-s' (`show-subtree'). Both expect to be used when point is on a heading line, and both apply to all the lines of that heading's "subtree": its body, all its subheadings, both direct and indirect, and all of their bodies. In other words, the subtree contains everything following this heading line, up to and not including the next heading of the same or higher rank. Intermediate between a visible subtree and an invisible one is having all the subheadings visible but none of the body. There are two commands for doing this, depending on whether you want to hide the bodies or make the subheadings visible. They are `M-x hide-leaves' and `M-x show-branches'. A little weaker than `show-branches' is `C-c C-i' (`show-children'). It makes just the direct subheadings visible--those one level down. Deeper subheadings remain invisible, if they were invisible. Two commands have a blanket effect on the whole file. `M-x hide-body' makes all body lines invisible, so that you see just the outline structure. `M-x show-all' makes all lines visible. These commands can be thought of as a pair of opposites even though `M-x show-all' applies to more than just body lines. The use of ellipses at the ends of visible lines can be turned off by setting `selective-display-ellipses' to `nil'. Then there is no visible indication of the presence of invisible lines. File: emacs, Node: Words, Next: Sentences, Prev: Text Mode, Up: Text Words ===== Emacs has commands for moving over or operating on words. By convention, the keys for them are all `Meta-' characters. `M-f' Move forward over a word (`forward-word'). `M-b' Move backward over a word (`backward-word'). `M-d' Kill up to the end of a word (`kill-word'). `M-DEL' Kill back to the beginning of a word (`backward-kill-word'). `M-@' Mark the end of the next word (`mark-word'). `M-t' Transpose two words; drag a word forward or backward across other words (`transpose-words'). Notice how these keys form a series that parallels the character-based `C-f', `C-b', `C-d', `C-t' and DEL. `M-@' is related to `C-@', which is an alias for `C-SPC'. The commands `Meta-f' (`forward-word') and `Meta-b' (`backward-word') move forward and backward over words. They are thus analogous to `Control-f' and `Control-b', which move over single characters. Like their `Control-' analogues, `Meta-f' and `Meta-b' move several words if given an argument. `Meta-f' with a negative argument moves backward, and `Meta-b' with a negative argument moves forward. Forward motion stops right after the last letter of the word, while backward motion stops right before the first letter. `Meta-d' (`kill-word') kills the word after point. To be precise, it kills everything from point to the place `Meta-f' would move to. Thus, if point is in the middle of a word, `Meta-d' kills just the part after point. If some punctuation comes between point and the next word, it is killed along with the word. (If you wish to kill only the next word but not the punctuation before it, simply do `Meta-f' to get the end, and kill the word backwards with `Meta-DEL'.) `Meta-d' takes arguments just like `Meta-f'. `Meta-DEL' (`backward-kill-word') kills the word before point. It kills everything from point back to where `Meta-b' would move to. If point is after the space in `FOO, BAR', then `FOO, ' is killed. (If you wish to kill just `FOO', do `Meta-b Meta-d' instead of `Meta-DEL'.) `Meta-t' (`transpose-words') exchanges the word before or containing point with the following word. The delimiter characters between the words do not move. For example, `FOO, BAR' transposes into `BAR, FOO' rather than `BAR FOO,'. *Note Transpose::, for more on transposition and on arguments to transposition commands. To operate on the next N words with an operation which applies between point and mark, you can either set the mark at point and then move over the words, or you can use the command `Meta-@' (`mark-word') which does not move point, but sets the mark where `Meta-f' would move to. It can be given arguments just like `Meta-f'. The word commands' understanding of syntax is completely controlled by the syntax table. Any character can, for example, be declared to be a word delimiter. *Note Syntax::. File: emacs, Node: Sentences, Next: Paragraphs, Prev: Words, Up: Text Sentences ========= The Emacs commands for manipulating sentences and paragraphs are mostly on `Meta-' keys, so as to be like the word-handling commands. `M-a' Move back to the beginning of the sentence (`backward-sentence'). `M-e' Move forward to the end of the sentence (`forward-sentence'). `M-k' Kill forward to the end of the sentence (`kill-sentence'). `C-x DEL' Kill back to the beginning of the sentence (`backward-kill-sentence'). The commands `Meta-a' and `Meta-e' (`backward-sentence' and `forward-sentence') move to the beginning and end of the current sentence, respectively. They were chosen to resemble `Control-a' and `Control-e', which move to the beginning and end of a line. Unlike them, `Meta-a' and `Meta-e' if repeated or given numeric arguments move over successive sentences. Emacs assumes that the typist's convention is followed, and thus considers a sentence to end wherever there is a `.', `?' or `!' followed by the end of a line or two spaces, with any number of `)', `]', `'', or `"' characters allowed in between. A sentence also begins or ends wherever a paragraph begins or ends. Neither `M-a' nor `M-e' moves past the newline or spaces beyond the sentence edge at which it is stopping. Just as `C-a' and `C-e' have a kill command, `C-k', to go with them, so `M-a' and `M-e' have a corresponding kill command `M-k' (`kill-sentence') which kills from point to the end of the sentence. With minus one as an argument it kills back to the beginning of the sentence. Larger arguments serve as a repeat count. There is a special command, `C-x DEL' (`backward-kill-sentence') for killing back to the beginning of a sentence, because this is useful when you change your mind in the middle of composing text. The variable `sentence-end' controls recognition of the end of a sentence. It is a regexp that matches the last few characters of a sentence, together with the whitespace following the sentence. Its normal value is "[.?!][]\"')]*\$$\\|\t\\| \$[ \t\n]*" This example is explained in the section on regexps. *Note Regexps::.