This is Info file ../../info/xemacs.info, produced by Makeinfo version 1.68 from the input file xemacs.texi. INFO-DIR-SECTION XEmacs Editor START-INFO-DIR-ENTRY * XEmacs: (xemacs). XEmacs Editor. END-INFO-DIR-ENTRY This file documents the XEmacs editor. Copyright (C) 1985, 1986, 1988 Richard M. Stallman. Copyright (C) 1991, 1992, 1993, 1994 Lucid, Inc. Copyright (C) 1993, 1994 Sun Microsystems, Inc. Copyright (C) 1995 Amdahl Corporation. 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: xemacs.info, Node: Specify Coding, Prev: Recognize Coding, Up: Mule Specifying a Coding System ========================== In cases where XEmacs does not automatically choose the right coding system, you can use these commands to specify one: `C-x f CODING ' Use coding system CODING for the visited file in the current buffer. `C-x c CODING ' Specify coding system CODING for the immediately following command. `C-x k CODING ' Use coding system CODING for keyboard input. `C-x t CODING ' Use coding system CODING for terminal output. `C-x p CODING ' Use coding system CODING for subprocess input and output in the current buffer. The command `C-x RET f' (`set-buffer-file-coding-system') specifies the file coding system for the current buffer--in other words, which coding system to use when saving or rereading the visited file. You specify which coding system using the minibuffer. Since this command applies to a file you have already visited, it affects only the way the file is saved. Another way to specify the coding system for a file is when you visit the file. First use the command `C-x c' (`universal-coding-system-argument'); this command uses the minibuffer to read a coding system name. After you exit the minibuffer, the specified coding system is used for *the immediately following command*. So if the immediately following command is `C-x C-f', for example, it reads the file using that coding system (and records the coding system for when the file is saved). Or if the immediately following command is `C-x C-w', it writes the file using that coding system. Other file commands affected by a specified coding system include `C-x C-i' and `C-x C-v', as well as the other-window variants of `C-x C-f'. In addition, if you run some file input commands with the precedent `C-u', you can specify coding system to read from minibuffer. So if the immediately following command is `C-x C-f', for example, it reads the file using that coding system (and records the coding system for when the file is saved). Other file commands affected by a specified coding system include `C-x C-i' and `C-x C-v', as well as the other-window variants of `C-x C-f'. The variable `default-buffer-file-coding-system' specifies the choice of coding system to use when you create a new file. It applies when you find a new file, and when you create a buffer and then save it in a file. Selecting a language environment typically sets this variable to a good choice of default coding system for that language environment. The command `C-x t' (`set-terminal-coding-system') specifies the coding system for terminal output. If you specify a character code for terminal output, all characters output to the terminal are translated into that coding system. This feature is useful for certain character-only terminals built to support specific languages or character sets--for example, European terminals that support one of the ISO Latin character sets. By default, output to the terminal is not translated at all. The command `C-x k' (`set-keyboard-coding-system') specifies the coding system for keyboard input. Character-code translation of keyboard input is useful for terminals with keys that send non-ASCII graphic characters--for example, some terminals designed for ISO Latin-1 or subsets of it. By default, keyboard input is not translated at all. There is a similarity between using a coding system translation for keyboard input, and using an input method: both define sequences of keyboard input that translate into single characters. However, input methods are designed to be convenient for interactive use by humans, and the sequences that are translated are typically sequences of ASCII printing characters. Coding systems typically translate sequences of non-graphic characters. The command `C-x p' (`set-buffer-process-coding-system') specifies the coding system for input and output to a subprocess. This command applies to the current buffer; normally, each subprocess has its own buffer, and thus you can use this command to specify translation to and from a particular subprocess by giving the command in the corresponding buffer. By default, process input and output are not translated at all. The variable `file-name-coding-system' specifies a coding system to use for encoding file names. If you set the variable to a coding system name (as a Lisp symbol or a string), XEmacs encodes file names using that coding system for all file operations. This makes it possible to use non-Latin-1 characters in file names--or, at least, those non-Latin-1 characters which the specified coding system can encode. By default, this variable is `nil', which implies that you cannot use non-Latin-1 characters in file names.  File: xemacs.info, Node: Major Modes, Next: Indentation, Prev: Mule, 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; at any time, each buffer has one major mode. 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. 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. , , and are changed frequently. In addition, commands which handle comments use the mode to determine how to delimit comments. 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 by Emacs for specific purposes and include Dired mode for buffers made by Dired (*note Dired::.), 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 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: xemacs.info, Node: Choosing Modes, Prev: Major Modes, Up: Major Modes Choosing Major Modes ==================== 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. Use a `M-x' command to explicitly select a new major mode. Add `-mode' to the name of a major mode to get the name of a command to select that mode. For example, to enter Lisp mode, execute `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 variable `auto-mode-alist' controls the correspondence between file names and major mode. 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)'. 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 non-blank 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 default mode 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 you visit a file that does not specify a major mode to use, or when you create a new buffer with `C-x b', Emacs uses the major mode 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: xemacs.info, Node: Indentation, Next: Text, Prev: Major Modes, Up: Top Indentation *********** `' Indent current line "appropriately" in a mode-dependent fashion. `' Perform followed by (`newline-and-indent'). `M-^' Merge two lines (`delete-indentation'). This would cancel out the effect of . `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 non-blank character on the current line (`back-to-indentation'). `C-M-\' Indent several lines to same column (`indent-region'). `C-x ' 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 details differ. Use the command to indent a line whatever the language. Each major mode defines this command to perform indentation appropriate for the particular language. In Lisp mode, aligns a line according to its depth in parentheses. No matter where in the line you are when you type , it aligns the line as a whole. In C mode, implements a subtle and sophisticated indentation style that knows about many aspects of C syntax. In Text mode, 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: xemacs.info, 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 '. To move over the indentation on a line, type `Meta-m' (`back-to-indentation'). This command, given anywhere on a line, positions point at the first non-blank character on the line. To insert an indented line before the current line, type `C-a C-o '. To make an indented line after the current line, use `C-e '. `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. Empty spaces are replaced by a single space, or by no space if at the beginning of a line, before a close parenthesis, or after an open parenthesis. 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 at the beginning of the line. A numeric argument specifies the column to indent to. Each line is shifted left or right so that its first non-blank character appears in that column. `C-x ' (`indent-rigidly') moves all 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 non-empty 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 in Indented Text mode. *Note Text::.  File: xemacs.info, 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-to-tab-stop'. This command inserts indentation before point, enough to reach the next tab stop column. Even if you are not in Text mode, this function is associated with `M-i' anyway. You can arbitrarily set the tab stops used by `M-i'. They are stored as a list of column-numbers in increasing order in the variable `tab-stop-list'. 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 the default `save-buffer'. `edit-tab-stops' records which buffer was current when you invoked it, and stores the tab stops in that buffer. Normally all buffers share the same tab stops and changing them in one buffer affects all. If you make `tab-stop-list' local in one buffer `edit-tab-stops' in that buffer edits only the local settings. Below is the text representing 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 help you see where the colons are and tell you 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: xemacs.info, 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 non-blank text. `M-x tabify' scans the region for sequences of spaces, and converts sequences of at least three spaces to tabs if that is possible without changing indentation. `M-x untabify' changes all tabs in the region to corresponding numbers of spaces.  File: xemacs.info, 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. In this sense of the word any file that you edit with Emacs is text. 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 and stylistic conventions that editor commands should support or use to advantage: conventions involving words, sentences, paragraphs, and capital letters. This chapter describes Emacs commands for all 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 a file contains plain text, 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 can 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: xemacs.info, Node: Text Mode, Next: Words, Prev: Text, Up: Text Text Mode ========= You should use Text mode--rather than Fundamental or Lisp mode--to edit files of text in a human language. Invoke `M-x text-mode' to enter Text mode. In Text mode, 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 unless they are 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 to run `indent-relative' (*note Indentation::.), and makes Auto Fill indent the lines it creates. As a result, a line made by Auto Filling, or by , is normally indented just like the previous line. Use `M-x indented-text-mode' to select this mode. Entering Text mode or Indented Text mode calls the value of the variable `text-mode-hook' with no arguments, 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. Two modes similar to Text mode are of use for editing text that is to be passed through a text formatter before achieving its final readable form. * Menu: * 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: xemacs.info, 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. Nroff mode differs from Text mode in only a few ways. All nroff command lines are considered paragraph separators, so that filling never garbles the nroff commands. Pages are separated by `.bp' commands. Comments start with backslash-doublequote. There are also three special commands that are not available 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 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 and you use to end a line containing an nroff command that opens a kind of grouping, Emacs automatically inserts the matching nroff command to close that grouping on the following line. For example, if you are at the beginning of a line and type `.(b ', the matching command `.)b' will be inserted on a new line following point. Entering Nroff mode calls the value of the variable `text-mode-hook' with no arguments, if that value exists and is not `nil'; then it does the same with the variable `nroff-mode-hook'.  File: xemacs.info, Node: TeX Mode, Next: Outline Mode, Prev: Nroff Mode, Up: Text Mode TeX Mode -------- TeX is a powerful text formatter written by Donald Knuth; like GNU Emacs, it is free. LaTeX is a simplified input format for TeX, implemented by TeX macros. It is part of 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, which are two distinct major modes that differ only slightly. These modes are designed for editing the two different input formats. The command `M-x tex-mode' looks at the contents of a buffer to determine whether it appears 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 one of the 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. (The total cost comes to $150 for domestic sites, $175 for foreign sites). The normal distribution is a tar tape, blocked 20, 1600 bpi, on an industry standard 2400 foot half-inch reel. The physical format for the 1/4 inch streamer cartridges uses QIC-11, 8000 bpi, 4-track serpentine recording for the SUN. Also, SystemV tapes can be written in cpio format, blocked 5120 bytes, ASCII headers.  File: xemacs.info, Node: TeX Editing, Next: TeX Print, Prev: TeX Mode, Up: TeX Mode TeX Editing Commands .................... Here are the special commands provided in TeX mode for editing the text of the file. `"' Insert, according to context, either ```' or `"' or `''' (`TeX-insert-quote'). `' Insert a paragraph break (two newlines) and check the previous paragraph for unbalanced braces or dollar signs (`tex-terminate- paragraph'). `M-x validate-tex-buffer' Check each paragraph in the buffer for unbalanced braces or dollar signs. `C-c {' Insert `{}' and position point between them (`tex-insert-braces'). `C-c }' Move forward past the next unmatched close brace (`up-list'). `C-c C-e' Close a block for LaTeX (`tex-close-latex-block'). In TeX, the character `"' is not normally used; you use ```' to start a quotation and `''' to end one. TeX mode defines the key `"' to insert ```' after whitespace or an open brace, `"' after a backslash, or `''' otherwise. This is done by the command `tex-insert-quote'. If you need the character `"' itself in unusual contexts, use `C-q' to insert it. Also, `"' with a numeric argument always inserts that number of `"' characters. In TeX mode, `$' 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 `C-c {' (`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 `C-c }' (`up-list') to move forward past the close brace. There are two commands for checking the matching of braces. (`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, not just braces, are matched in TeX mode. This is wrong if you want to check 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: xemacs.info, 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 using `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, appears 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 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 them, 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, insert two special strings in the file: `%**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 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, so you don't need to do anything special to identify the header. When you enter either kind of TeX mode, Emacs calls with no arguments the value of the variable `text-mode-hook', if that value exists and is not `nil'. Emacs then calls the variable `TeX-mode-hook' and either `plain-TeX-mode-hook' or `LaTeX-mode-hook' under the same conditions.  File: xemacs.info, Node: Outline Mode, Prev: TeX Mode, Up: Text Mode Outline Mode ------------ Outline mode is a major mode similar to 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. When you enter Outline mode, Emacs 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 as well; yanking everything 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: xemacs.info, 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 can 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 the same length, 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. Saving does not change the visibility status of a line inside Emacs.  File: xemacs.info, Node: Outline Motion, Next: Outline Visibility, Prev: Outline Format, Up: Outline Mode Outline Motion Commands ....................... Some special commands in Outline mode 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: xemacs.info, 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 exist as 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-d' 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 should 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, one that hides the bodies and one that makes 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. 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. You can think of these commands as a pair of opposites even though `M-x show-all' applies to more than just body lines. You can turn off the use of ellipses at the ends of visible lines by setting `selective-display-ellipses' to `nil'. The result is no visible indication of the presence of invisible lines.  File: xemacs.info, 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-' 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 . `M-@' is related to `C-@', which is an alias for `C-'. The commands `Meta-f' (`forward-word') and `Meta-b' (`backward-word') move forward and backward over words. They are 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 after the last letter of the word, while backward motion stops 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. (To kill only the next word but not the punctuation before it, simply type `Meta-f' to get to the end and kill the word backwards with `Meta-'.) `Meta-d' takes arguments just like `Meta-f'. `Meta-' (`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. To kill just `FOO', type `Meta-b Meta-d' instead of `Meta-'. `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, transposing `FOO, BAR' results in `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. For example, any character can be declared to be a word delimiter. *Note Syntax::.  File: xemacs.info, Node: Sentences, Next: Paragraphs, Prev: Words, Up: Text Sentences ========= The Emacs commands for manipulating sentences and paragraphs are mostly on `Meta-' keys, and therefore are 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 ' 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 resemble `Control-a' and `Control-e', which move to the beginning and end of a line. Unlike their counterparts, `Meta-a' and `Meta-e' move over successive sentences if repeated or given numeric arguments. Emacs assumes 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. `M-a' and `M-e' have a corresponding kill command, just like `C-a' and `C-e' have `C-k'. The command is `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 repeat counts. There is a special command, `C-x ' (`backward-kill-sentence'), for killing back to the beginning of a sentence, which 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::.  File: xemacs.info, Node: Paragraphs, Next: Pages, Prev: Sentences, Up: Text Paragraphs ========== The Emacs commands for manipulating paragraphs are also `Meta-' keys. `M-[' Move back to previous paragraph beginning (`backward-paragraph'). `M-]' Move forward to next paragraph end (`forward-paragraph'). `M-h' Put point and mark around this or next paragraph (`mark-paragraph'). `Meta-[' moves to the beginning of the current or previous paragraph, while `Meta-]' moves to the end of the current or next paragraph. Blank lines and text formatter command lines separate paragraphs and are not part of any paragraph. An indented line starts a new paragraph. In major modes for programs (as opposed to Text mode), paragraphs begin and end only at blank lines. As a result, the paragraph commands continue to be useful even though there are no paragraphs per se. When there is a fill prefix, paragraphs are delimited by all lines which don't start with the fill prefix. *Note Filling::. To operate on a paragraph, you can use the command `Meta-h' (`mark-paragraph') to set the region around it. This command puts point at the beginning and mark at the end of the paragraph point was in. If point is between paragraphs (in a run of blank lines or at a boundary), the paragraph following point is surrounded by point and mark. If there are blank lines preceding the first line of the paragraph, one of the blank lines is included in the region. Thus, for example, `M-h C-w' kills the paragraph around or after point. The precise definition of a paragraph boundary is controlled by the variables `paragraph-separate' and `paragraph-start'. The value of `paragraph-start' is a regexp that matches any line that either starts or separates paragraphs. The value of `paragraph-separate' is another regexp that matches only lines that separate paragraphs without being part of any paragraph. Lines that start a new paragraph and are contained in it must match both regexps. For example, normally `paragraph-start' is `"^[ \t\n\f]"' and `paragraph-separate' is `"^[ \t\f]*$"'. Normally it is desirable for page boundaries to separate paragraphs. The default values of these variables recognize the usual separator for pages.