This is ../info/emacs, produced by makeinfo version 4.3 from emacs.texi. This is the Fourteenth edition of the `GNU Emacs Manual', updated for Emacs version 21.3. INFO-DIR-SECTION Emacs START-INFO-DIR-ENTRY * Emacs: (emacs). The extensible self-documenting text editor. END-INFO-DIR-ENTRY Published by the Free Software Foundation 59 Temple Place, Suite 330 Boston, MA 02111-1307 USA Copyright (C) 1985,1986,1987,1993,1994,1995,1996,1997,1998,1999,2000,2001,2002 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Sections being "The GNU Manifesto", "Distribution" and "GNU GENERAL PUBLIC LICENSE", with the Front-Cover texts being "A GNU Manual," and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled "GNU Free Documentation License." (a) The FSF's Back-Cover Text is: "You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development."  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 ' Kill back to the beginning of the sentence (`backward-kill-sentence'). The commands `M-a' and `M-e' (`backward-sentence' and `forward-sentence') move to the beginning and end of the current sentence, respectively. They were chosen to resemble `C-a' and `C-e', which move to the beginning and end of a line. Unlike them, `M-a' and `M-e' if repeated or given numeric arguments move over successive sentences. Moving backward over a sentence places point just before the first character of the sentence; moving forward places point right after the punctuation that ends the sentence. Neither one moves over the whitespace at the sentence boundary. 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 also a command, `C-x ' (`backward-kill-sentence'), for killing back to the beginning of a sentence. This command is useful when you change your mind in the middle of composing text. The sentence commands assume that you follow the American typist's convention of putting two spaces at the end of a sentence; they consider 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. 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 "[.?!][]\"')]*\\($\\| $\\|\t\\| \\)[ \t\n]*" This example is explained in the section on regexps. *Note Regexps::. If you want to use just one space between sentences, you should set `sentence-end' to this value: "[.?!][]\"')]*\\($\\|\t\\| \\)[ \t\n]*" You should also set the variable `sentence-end-double-space' to `nil' so that the fill commands expect and leave just one space at the end of a sentence. Note that this makes it impossible to distinguish between periods that end sentences and those that indicate abbreviations.  File: emacs, 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'). `M-{' moves to the beginning of the current or previous paragraph, while `M-}' moves to the end of the current or next paragraph. Blank lines and text-formatter command lines separate paragraphs and are not considered part of any paragraph. In Fundamental mode, but not in Text mode, an indented line also starts a new paragraph. (If a paragraph is preceded by a blank line, these commands treat that blank line as the beginning of the paragraph.) In major modes for programs, paragraphs begin and end only at blank lines. This makes the paragraph commands continue to be useful even though there are no paragraphs per se. When there is a fill prefix, then paragraphs are delimited by all lines which don't start with the fill prefix. *Note Filling::. When you wish to operate on a paragraph, you can use the command `M-h' (`mark-paragraph') to set the region around it. Thus, for example, `M-h C-w' kills the paragraph around or after point. The `M-h' command puts point at the beginning and mark at the end of the paragraph point was in. In Transient Mark mode, it activates the mark. 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 these blank lines is included in the region. 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 should match any line that either starts or separates paragraphs. The value of `paragraph-separate' is another regexp that should match only lines that separate paragraphs without being part of any paragraph (for example, blank lines). Lines that start a new paragraph and are contained in it must match only `paragraph-start', not `paragraph-separate'. For example, in Fundamental mode, `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.  File: emacs, Node: Pages, Next: Filling, Prev: Paragraphs, Up: Text Pages ===== Files are often thought of as divided into "pages" by the "formfeed" character (ASCII control-L, octal code 014). When you print hardcopy for a file, this character forces a page break; thus, each page of the file goes on a separate page on paper. Most Emacs commands treat the page-separator character just like any other character: you can insert it with `C-q C-l', and delete it with . Thus, you are free to paginate your file or not. However, since pages are often meaningful divisions of the file, Emacs provides commands to move over them and operate on them. `C-x [' Move point to previous page boundary (`backward-page'). `C-x ]' Move point to next page boundary (`forward-page'). `C-x C-p' Put point and mark around this page (or another page) (`mark-page'). `C-x l' Count the lines in this page (`count-lines-page'). The `C-x [' (`backward-page') command moves point to immediately after the previous page delimiter. If point is already right after a page delimiter, it skips that one and stops at the previous one. A numeric argument serves as a repeat count. The `C-x ]' (`forward-page') command moves forward past the next page delimiter. The `C-x C-p' command (`mark-page') puts point at the beginning of the current page and the mark at the end. The page delimiter at the end is included (the mark follows it). The page delimiter at the front is excluded (point follows it). In Transient Mark mode, this command activates the mark. `C-x C-p C-w' is a handy way to kill a page to move it elsewhere. If you move to another page delimiter with `C-x [' and `C-x ]', then yank the killed page, all the pages will be properly delimited once again. The reason `C-x C-p' includes only the following page delimiter in the region is to ensure that. A numeric argument to `C-x C-p' is used to specify which page to go to, relative to the current one. Zero means the current page. One means the next page, and -1 means the previous one. The `C-x l' command (`count-lines-page') is good for deciding where to break a page in two. It displays in the echo area the total number of lines in the current page, and then divides it up into those preceding the current line and those following, as in Page has 96 (72+25) lines Notice that the sum is off by one; this is correct if point is not at the beginning of a line. The variable `page-delimiter' controls where pages begin. Its value is a regexp that matches the beginning of a line that separates pages. The normal value of this variable is `"^\f"', which matches a formfeed character at the beginning of a line.  File: emacs, Node: Filling, Next: Case, Prev: Pages, Up: Text Filling Text ============ "Filling" text means breaking it up into lines that fit a specified width. Emacs does filling in two ways. In Auto Fill mode, inserting text with self-inserting characters also automatically fills it. There are also explicit fill commands that you can use when editing text leaves it unfilled. When you edit formatted text, you can specify a style of filling for each portion of the text (*note Formatted Text::). * Menu: * Auto Fill:: Auto Fill mode breaks long lines automatically. * Refill:: Keeping paragraphs filled. * Fill Commands:: Commands to refill paragraphs and center lines. * Fill Prefix:: Filling paragraphs that are indented or in a comment, etc. * Adaptive Fill:: How Emacs can determine the fill prefix automatically.  File: emacs, Node: Auto Fill, Next: Refill, Up: Filling Auto Fill Mode -------------- "Auto Fill" mode is a minor mode in which lines are broken automatically when they become too wide. Breaking happens only when you type a or . `M-x auto-fill-mode' Enable or disable Auto Fill mode. `' `' In Auto Fill mode, break lines when appropriate. `M-x auto-fill-mode' turns Auto Fill mode on if it was off, or off if it was on. With a positive numeric argument it always turns Auto Fill mode on, and with a negative argument always turns it off. You can see when Auto Fill mode is in effect by the presence of the word `Fill' in the mode line, inside the parentheses. Auto Fill mode is a minor mode which is enabled or disabled for each buffer individually. *Note Minor Modes::. In Auto Fill mode, lines are broken automatically at spaces when they get longer than the desired width. Line breaking and rearrangement takes place only when you type or . If you wish to insert a space or newline without permitting line-breaking, type `C-q ' or `C-q C-j' (recall that a newline is really a control-J). Also, `C-o' inserts a newline without line breaking. Auto Fill mode works well with programming-language modes, because it indents new lines with . If a line ending in a comment gets too long, the text of the comment is split into two comment lines. Optionally, new comment delimiters are inserted at the end of the first line and the beginning of the second so that each line is a separate comment; the variable `comment-multi-line' controls the choice (*note Comments::). Adaptive filling (*note Adaptive Fill::) works for Auto Filling as well as for explicit fill commands. It takes a fill prefix automatically from the second or first line of a paragraph. Auto Fill mode does not refill entire paragraphs; it can break lines but cannot merge lines. So editing in the middle of a paragraph can result in a paragraph that is not correctly filled. The easiest way to make the paragraph properly filled again is usually with the explicit fill commands. *Note Fill Commands::. Many users like Auto Fill mode and want to use it in all text files. The section on init files says how to arrange this permanently for yourself. *Note Init File::.  File: emacs, Node: Refill, Next: Fill Commands, Prev: Auto Fill, Up: Filling Refill Mode ----------- Refill minor mode provides support for keeping paragraphs filled as you type or modify them in other ways. It provides an effect similar to typical word processor behavior. This works by running a paragraph-filling command at suitable times. When you are typing text, only characters which normally trigger auto filling, like the space character, will trigger refilling. This is to avoid making it too slow. Apart from self-inserting characters, other commands which modify the text cause refilling. The current implementation is preliminary and probably not robust. We expect to improve on it. To toggle the use of Refill mode in the current buffer, type `M-x refill-mode'.  File: emacs, Node: Fill Commands, Next: Fill Prefix, Prev: Refill, Up: Filling Explicit Fill Commands ---------------------- `M-q' Fill current paragraph (`fill-paragraph'). `C-x f' Set the fill column (`set-fill-column'). `M-x fill-region' Fill each paragraph in the region (`fill-region'). `M-x fill-region-as-paragraph' Fill the region, considering it as one paragraph. `M-s' Center a line. To refill a paragraph, use the command `M-q' (`fill-paragraph'). This operates on the paragraph that point is inside, or the one after point if point is between paragraphs. Refilling works by removing all the line-breaks, then inserting new ones where necessary. To refill many paragraphs, use `M-x fill-region', which divides the region into paragraphs and fills each of them. `M-q' and `fill-region' use the same criteria as `M-h' for finding paragraph boundaries (*note Paragraphs::). For more control, you can use `M-x fill-region-as-paragraph', which refills everything between point and mark. This command deletes any blank lines within the region, so separate blocks of text end up combined into one block. A numeric argument to `M-q' causes it to "justify" the text as well as filling it. This means that extra spaces are inserted to make the right margin line up exactly at the fill column. To remove the extra spaces, use `M-q' with no argument. (Likewise for `fill-region'.) Another way to control justification, and choose other styles of filling, is with the `justification' text property; see *Note Format Justification::. The command `M-s' (`center-line') centers the current line within the current fill column. With an argument N, it centers N lines individually and moves past them. The maximum line width for filling is in the variable `fill-column'. Altering the value of `fill-column' makes it local to the current buffer; until that time, the default value is in effect. The default is initially 70. *Note Locals::. The easiest way to set `fill-column' is to use the command `C-x f' (`set-fill-column'). With a numeric argument, it uses that as the new fill column. With just `C-u' as argument, it sets `fill-column' to the current horizontal position of point. Emacs commands normally consider a period followed by two spaces or by a newline as the end of a sentence; a period followed by just one space indicates an abbreviation and not the end of a sentence. To preserve the distinction between these two ways of using a period, the fill commands do not break a line after a period followed by just one space. If the variable `sentence-end-double-space' is `nil', the fill commands expect and leave just one space at the end of a sentence. Ordinarily this variable is `t', so the fill commands insist on two spaces for the end of a sentence, as explained above. *Note Sentences::. If the variable `colon-double-space' is non-`nil', the fill commands put two spaces after a colon. Some languages do not use period to indicate end of sentence. For example, a sentence in Thai text ends with double space but without a period. Set the variable `sentence-end-without-period' to `t' to tell the sentence commands that a period is not necessary.  File: emacs, Node: Fill Prefix, Next: Adaptive Fill, Prev: Fill Commands, Up: Filling The Fill Prefix --------------- To fill a paragraph in which each line starts with a special marker (which might be a few spaces, giving an indented paragraph), you can use the "fill prefix" feature. The fill prefix is a string that Emacs expects every line to start with, and which is not included in filling. You can specify a fill prefix explicitly; Emacs can also deduce the fill prefix automatically (*note Adaptive Fill::). `C-x .' Set the fill prefix (`set-fill-prefix'). `M-q' Fill a paragraph using current fill prefix (`fill-paragraph'). `M-x fill-individual-paragraphs' Fill the region, considering each change of indentation as starting a new paragraph. `M-x fill-nonuniform-paragraphs' Fill the region, considering only paragraph-separator lines as starting a new paragraph. To specify a fill prefix, move to a line that starts with the desired prefix, put point at the end of the prefix, and give the command `C-x .' (`set-fill-prefix'). That's a period after the `C-x'. To turn off the fill prefix, specify an empty prefix: type `C-x .' with point at the beginning of a line. When a fill prefix is in effect, the fill commands remove the fill prefix from each line before filling and insert it on each line after filling. Auto Fill mode also inserts the fill prefix automatically when it makes a new line. The `C-o' command inserts the fill prefix on new lines it creates, when you use it at the beginning of a line (*note Blank Lines::). Conversely, the command `M-^' deletes the prefix (if it occurs) after the newline that it deletes (*note Indentation::). For example, if `fill-column' is 40 and you set the fill prefix to `;; ', then `M-q' in the following text ;; This is an ;; example of a paragraph ;; inside a Lisp-style comment. produces this: ;; This is an example of a paragraph ;; inside a Lisp-style comment. Lines that do not start with the fill prefix are considered to start paragraphs, both in `M-q' and the paragraph commands; this gives good results for paragraphs with hanging indentation (every line indented except the first one). Lines which are blank or indented once the prefix is removed also separate or start paragraphs; this is what you want if you are writing multi-paragraph comments with a comment delimiter on each line. You can use `M-x fill-individual-paragraphs' to set the fill prefix for each paragraph automatically. This command divides the region into paragraphs, treating every change in the amount of indentation as the start of a new paragraph, and fills each of these paragraphs. Thus, all the lines in one "paragraph" have the same amount of indentation. That indentation serves as the fill prefix for that paragraph. `M-x fill-nonuniform-paragraphs' is a similar command that divides the region into paragraphs in a different way. It considers only paragraph-separating lines (as defined by `paragraph-separate') as starting a new paragraph. Since this means that the lines of one paragraph may have different amounts of indentation, the fill prefix used is the smallest amount of indentation of any of the lines of the paragraph. This gives good results with styles that indent a paragraph's first line more or less that the rest of the paragraph. The fill prefix is stored in the variable `fill-prefix'. Its value is a string, or `nil' when there is no fill prefix. 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::. The `indentation' text property provides another way to control the amount of indentation paragraphs receive. *Note Format Indentation::.  File: emacs, Node: Adaptive Fill, Prev: Fill Prefix, Up: Filling Adaptive Filling ---------------- The fill commands can deduce the proper fill prefix for a paragraph automatically in certain cases: either whitespace or certain punctuation characters at the beginning of a line are propagated to all lines of the paragraph. If the paragraph has two or more lines, the fill prefix is taken from the paragraph's second line, but only if it appears on the first line as well. If a paragraph has just one line, fill commands _may_ take a prefix from that line. The decision is complicated because there are three reasonable things to do in such a case: * Use the first line's prefix on all the lines of the paragraph. * Indent subsequent lines with whitespace, so that they line up under the text that follows the prefix on the first line, but don't actually copy the prefix from the first line. * Don't do anything special with the second and following lines. All three of these styles of formatting are commonly used. So the fill commands try to determine what you would like, based on the prefix that appears and on the major mode. Here is how. If the prefix found on the first line matches `adaptive-fill-first-line-regexp', or if it appears to be a comment-starting sequence (this depends on the major mode), then the prefix found is used for filling the paragraph, provided it would not act as a paragraph starter on subsequent lines. Otherwise, the prefix found is converted to an equivalent number of spaces, and those spaces are used as the fill prefix for the rest of the lines, provided they would not act as a paragraph starter on subsequent lines. In Text mode, and other modes where only blank lines and page delimiters separate paragraphs, the prefix chosen by adaptive filling never acts as a paragraph starter, so it can always be used for filling. The variable `adaptive-fill-regexp' determines what kinds of line beginnings can serve as a fill prefix: any characters at the start of the line that match this regular expression are used. If you set the variable `adaptive-fill-mode' to `nil', the fill prefix is never chosen automatically. You can specify more complex ways of choosing a fill prefix automatically by setting the variable `adaptive-fill-function' to a function. This function is called with point after the left margin of a line, and it should return the appropriate fill prefix based on that line. If it returns `nil', that means it sees no fill prefix in that line.  File: emacs, Node: Case, Next: Text Mode, Prev: Filling, Up: Text Case Conversion Commands ======================== Emacs has commands for converting either a single word or any arbitrary range of text to upper case or to lower case. `M-l' Convert following word to lower case (`downcase-word'). `M-u' Convert following word to upper case (`upcase-word'). `M-c' Capitalize the following word (`capitalize-word'). `C-x C-l' Convert region to lower case (`downcase-region'). `C-x C-u' Convert region to upper case (`upcase-region'). The word conversion commands are the most useful. `M-l' (`downcase-word') converts the word after point to lower case, moving past it. Thus, repeating `M-l' converts successive words. `M-u' (`upcase-word') converts to all capitals instead, while `M-c' (`capitalize-word') puts the first letter of the word into upper case and the rest into lower case. All these commands convert several words at once if given an argument. They are especially convenient for converting a large amount of text from all upper case to mixed case, because you can move through the text using `M-l', `M-u' or `M-c' on each word as appropriate, occasionally using `M-f' instead to skip a word. When given a negative argument, the word case conversion commands apply to the appropriate number of words before point, but do not move point. This is convenient when you have just typed a word in the wrong case: you can give the case conversion command and continue typing. If a word case conversion command is given in the middle of a word, it applies only to the part of the word which follows point. This is just like what `M-d' (`kill-word') does. With a negative argument, case conversion applies only to the part of the word before point. The other case conversion commands are `C-x C-u' (`upcase-region') and `C-x C-l' (`downcase-region'), which convert everything between point and mark to the specified case. Point and mark do not move. The region case conversion commands `upcase-region' and `downcase-region' are normally disabled. This means that they ask for confirmation if you try to use them. When you confirm, you may enable the command, which means it will not ask for confirmation again. *Note Disabling::.  File: emacs, Node: Text Mode, Next: Outline Mode, Prev: Case, Up: Text Text Mode ========= When you edit files of text in a human language, it's more convenient to use Text mode rather than Fundamental mode. To enter Text mode, type `M-x text-mode'. In Text mode, only blank lines and page delimiters separate paragraphs. As a result, paragraphs can be indented, and adaptive filling determines what indentation to use when filling a paragraph. *Note Adaptive Fill::. Text mode defines to run `indent-relative' (*note Indentation::), so that you can conveniently indent a line like the previous line. When the previous line is not indented, `indent-relative' runs `tab-to-tab-stop', which uses Emacs tab stops that you can set (*note Tab Stops::). Text mode turns off the features concerned with comments except when you explicitly invoke them. It changes the syntax table so that periods are not considered part of a word, while apostrophes, backspaces and underlines are considered part of words. If you indent the first lines of paragraphs, then you should use Paragraph-Indent Text mode rather than Text mode. In this mode, you do not need to have blank lines between paragraphs, because the first-line indentation is sufficient to start a paragraph; however paragraphs in which every line is indented are not supported. Use `M-x paragraph-indent-text-mode' to enter this mode. Use `M-x paragraph-indent-minor-mode' to enter an equivalent minor mode, for instance during mail composition. Text mode, and all the modes based on it, define `M-' as the command `ispell-complete-word', which performs completion of the partial word in the buffer before point, using the spelling dictionary as the space of possible words. *Note Spelling::. Entering Text mode runs the hook `text-mode-hook'. Other major modes related to Text mode also run this hook, followed by hooks of their own; this includes Paragraph-Indent Text mode, Nroff mode, TeX mode, Outline mode, and Mail mode. Hook functions on `text-mode-hook' can look at the value of `major-mode' to see which of these modes is actually being entered. *Note Hooks::. Emacs provides two other modes for editing text that is to be passed through a text formatter to produce fancy formatted printed output. *Note Nroff Mode::, for editing input to the formatter nroff. *Note TeX Mode::, for editing input to the formatter TeX. Another 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. *Note Outline Mode::.  File: emacs, Node: Outline Mode, Next: TeX Mode, Prev: Text Mode, Up: Text 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 the outline structure. Type `M-x outline-mode' to switch to Outline mode as the major mode of the current buffer. When Outline mode makes a line invisible, the line 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). Editing commands that operate on lines, such as `C-n' and `C-p', treat the text of the invisible line as part of the previous visible line. Killing an entire visible line, including its terminating newline, really kills all the following invisible lines along with it. Outline minor mode provides the same commands as the major mode, Outline mode, but you can use it in conjunction with other major modes. Type `M-x outline-minor-mode' to enable the Outline minor mode in the current buffer. You can also specify this in the text of a file, with a file local variable of the form `mode: outline-minor' (*note File Variables::). The major mode, Outline mode, provides special key bindings on the `C-c' prefix. Outline minor mode provides similar bindings with `C-c @' as the prefix; this is to reduce the conflicts with the major mode's special commands. (The variable `outline-minor-mode-prefix' controls the prefix used.) Entering Outline mode runs the hook `text-mode-hook' followed by the hook `outline-mode-hook' (*note Hooks::). * 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. * Views: Outline Views. Outlines and multiple views. * Foldout:: Folding editing.  File: emacs, Node: Outline Format, Next: Outline Motion, 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 with 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 Another 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 left margin) 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'. You can change the rule for calculating the level of a heading line by setting the variable `outline-level'. The value of `outline-level' should be a function that takes no arguments and returns the level of the current heading. Some major modes such as C, Nroff, and Emacs Lisp mode set this variable and `outline-regexp' in order to work with Outline minor mode.  File: emacs, Node: Outline Motion, Next: Outline Visibility, Prev: Outline Format, Up: Outline Mode Outline Motion Commands ----------------------- Outline mode provides special motion commands 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' (`outline-next-visible-heading') moves down to the next heading line. `C-c C-p' (`outline-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 powerful motion commands understand the level structure of headings. `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, Next: Outline Views, 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. `C-c C-t' Make all body lines in the buffer invisible (`hide-body'). `C-c C-a' Make all lines in the buffer visible (`show-all'). `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'). `C-c C-l' Make the body of this heading line, and of all its subheadings, invisible (`hide-leaves'). `C-c C-k' Make all subheadings of this heading line, at all levels, visible (`show-branches'). `C-c C-i' Make immediate subheadings (one level down) of this heading line visible (`show-children'). `C-c C-c' Make this heading line's body invisible (`hide-entry'). `C-c C-e' Make this heading line's body visible (`show-entry'). `C-c C-q' Hide everything except the top N levels of heading lines (`hide-sublevels'). `C-c C-o' Hide everything except for the heading or body that point is in, plus the headings leading up from there to the top level of the outline (`hide-other'). Two commands that are exact opposites are `C-c C-c' (`hide-entry') and `C-c C-e' (`show-entry'). They are used with point on a heading line, and apply only to the body lines of that heading. Subheadings and their bodies are not affected. Two more powerful opposites are `C-c C-d' (`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 `C-c C-l' (`hide-leaves') and `C-c C-k' (`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. `C-c C-t' (`hide-body') makes all body lines invisible, so that you see just the outline structure. `C-c C-a' (`show-all') makes all lines visible. These commands can be thought of as a pair of opposites even though `C-c C-a' applies to more than just body lines. The command `C-c C-q' (`hide-sublevels') hides all but the top level headings. With a numeric argument N, it hides everything except the top N levels of heading lines. The command `C-c C-o' (`hide-other') hides everything except the heading or body text that point is in, plus its parents (the headers leading up from there to top level in the outline). You can turn off the use of ellipses at the ends of visible lines by setting `selective-display-ellipses' to `nil'. Then there is no visible indication of the presence of invisible lines. When incremental search finds text that is hidden by Outline mode, it makes that part of the buffer visible. If you exit the search at that position, the text remains visible.  File: emacs, Node: Outline Views, Next: Foldout, Prev: Outline Visibility, Up: Outline Mode Viewing One Outline in Multiple Views ------------------------------------- You can display two views of a single outline at the same time, in different windows. To do this, you must create an indirect buffer using `M-x make-indirect-buffer'. The first argument of this command is the existing outline buffer name, and its second argument is the name to use for the new indirect buffer. *Note Indirect Buffers::. Once the indirect buffer exists, you can display it in a window in the normal fashion, with `C-x 4 b' or other Emacs commands. The Outline mode commands to show and hide parts of the text operate on each buffer independently; as a result, each buffer can have its own view. If you want more than two views on the same outline, create additional indirect buffers.  File: emacs, Node: Foldout, Prev: Outline Views, Up: Outline Mode Folding Editing --------------- The Foldout package extends Outline mode and Outline minor mode with "folding" commands. The idea of folding is that you zoom in on a nested portion of the outline, while hiding its relatives at higher levels. Consider an Outline mode buffer all the text and subheadings under level-1 headings hidden. To look at what is hidden under one of these headings, you could use `C-c C-e' (`M-x show-entry') to expose the body, or `C-c C-i' to expose the child (level-2) headings. With Foldout, you use `C-c C-z' (`M-x foldout-zoom-subtree'). This exposes the body and child subheadings, and narrows the buffer so that only the level-1 heading, the body and the level-2 headings are visible. Now to look under one of the level-2 headings, position the cursor on it and use `C-c C-z' again. This exposes the level-2 body and its level-3 child subheadings and narrows the buffer again. Zooming in on successive subheadings can be done as much as you like. A string in the mode line shows how deep you've gone. When zooming in on a heading, to see only the child subheadings specify a numeric argument: `C-u C-c C-z'. The number of levels of children can be specified too (compare `M-x show-children'), e.g. `M-2 C-c C-z' exposes two levels of child subheadings. Alternatively, the body can be specified with a negative argument: `M-- C-c C-z'. The whole subtree can be expanded, similarly to `C-c C-s' (`M-x show-subtree'), by specifying a zero argument: `M-0 C-c C-z'. While you're zoomed in, you can still use Outline mode's exposure and hiding functions without disturbing Foldout. Also, since the buffer is narrowed, "global" editing actions will only affect text under the zoomed-in heading. This is useful for restricting changes to a particular chapter or section of your document. To unzoom (exit) a fold, use `C-c C-x' (`M-x foldout-exit-fold'). This hides all the text and subheadings under the top-level heading and returns you to the previous view of the buffer. Specifying a numeric argument exits that many levels of folds. Specifying a zero argument exits all folds. To cancel the narrowing of a fold without hiding the text and subheadings, specify a negative argument. For example, `M--2 C-c C-x' exits two folds and leaves the text and subheadings exposed. Foldout mode also provides mouse commands for entering and exiting folds, and for showing and hiding text: `M-C-Mouse-1' zooms in on the heading clicked on single click: expose body. double click: expose subheadings. triple click: expose body and subheadings. quad click: expose entire subtree. `M-C-Mouse-2' exposes text under the heading clicked on single click: expose body. double click: expose subheadings. triple click: expose body and subheadings. quad click: expose entire subtree. `M-C-Mouse-3' hides text under the heading clicked on or exits fold single click: hide subtree. double click: exit fold and hide text. triple click: exit fold without hiding text. quad click: exit all folds and hide text. You can specify different modifier keys (instead of `Control-Meta-') by setting `foldout-mouse-modifiers'; but if you have already loaded the `foldout.el' library, you must reload it in order for this to take effect. To use the Foldout package, you can type `M-x load-library foldout '; or you can arrange for to do that automatically by putting this in your `.emacs' file: (eval-after-load "outline" '(require 'foldout))  File: emacs, Node: TeX Mode, Next: Nroff Mode, Prev: Outline Mode, Up: Text 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. SliTeX is a special form of LaTeX.(1) 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 three variants, Plain TeX mode, LaTeX mode, and SliTeX mode (these three distinct major modes differ only slightly). They are designed for editing the three different formats. The command `M-x tex-mode' looks at the contents of the buffer to determine whether the contents appear to be either LaTeX input or SliTeX input; if so, it selects the appropriate mode. If the file contents do not appear to be LaTeX or SliTeX, it selects Plain TeX mode. If the contents are insufficient to determine this, the variable `tex-default-mode' controls which mode is used. When `M-x tex-mode' does not guess right, you can use the commands `M-x plain-tex-mode', `M-x latex-mode', and `M-x slitex-mode' to select explicitly the particular variants of TeX mode. * Menu: * Editing: TeX Editing. Special commands for editing in TeX mode. * LaTeX: LaTeX Editing. Additional commands for LaTeX input files. * Printing: TeX Print. Commands for printing part of a file with TeX. * Misc: TeX Misc. Customization of TeX mode, and related features. ---------- Footnotes ---------- (1) SliTeX is obsoleted by the `slides' document class in recent LaTeX versions.  File: emacs, Node: TeX Editing, Next: LaTeX Editing, 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'). `C-j' Insert a paragraph break (two newlines) and check the previous paragraph for unbalanced braces or dollar signs (`tex-terminate-paragraph'). `M-x tex-validate-region' Check each paragraph in the region 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'). In TeX, the character `"' is not normally used; we use ```' to start a quotation and `''' to end one. To make editing easier under this formatting convention, TeX mode overrides the normal meaning of the key `"' with a command that inserts a pair of single-quotes or backquotes (`tex-insert-quote'). To be precise, this command inserts ```' after whitespace or an open brace, `"' after a backslash, and `''' after any other character. 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. You can turn off the feature of `"' expansion by eliminating that binding in the local map (*note Key Bindings::). 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. TeX uses braces as delimiters that must match. Some users prefer to keep braces balanced at all times, rather than inserting them singly. 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. `C-j' (`tex-terminate-paragraph') checks the paragraph before point, and inserts two newlines to start a new paragraph. It outputs a message in the echo area if any mismatch is found. `M-x tex-validate-region' checks a region, paragraph by paragraph. The errors are listed in the `*Occur*' buffer, and you can use `C-c C-c' or `Mouse-2' in that buffer to go to a particular mismatch. Note that Emacs commands count square brackets and parentheses in TeX mode, not just braces. This is not strictly correct 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.  File: emacs, Node: LaTeX Editing, Next: TeX Print, Prev: TeX Editing, Up: TeX Mode LaTeX Editing Commands ---------------------- LaTeX mode, and its variant, SliTeX mode, provide a few extra features not applicable to plain TeX. `C-c C-o' Insert `\begin' and `\end' for LaTeX block and position point on a line between them (`tex-latex-block'). `C-c C-e' Close the innermost LaTeX block not yet closed (`tex-close-latex-block'). In LaTeX input, `\begin' and `\end' commands are used to group blocks of text. To insert a `\begin' and a matching `\end' (on a new line following the `\begin'), use `C-c C-o' (`tex-latex-block'). A blank line is inserted between the two, and point is left there. You can use completion when you enter the block type; to specify additional block type names beyond the standard list, set the variable `latex-block-names'. For example, here's how to add `theorem', `corollary', and `proof': (setq latex-block-names '("theorem" "corollary" "proof")) In LaTeX input, `\begin' and `\end' commands must balance. You can use `C-c C-e' (`tex-close-latex-block') to insert automatically a matching `\end' to match the last unmatched `\begin'. It indents the `\end' to match the corresponding `\begin'. It inserts a newline after `\end' if point is at the beginning of a line.