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1 | @c This is part of the Emacs manual. |
2 | @c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 2000, 2001, | |
114f9c96 | 3 | @c 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. |
8cf51b2c GM |
4 | @c See file emacs.texi for copying conditions. |
5 | @node Basic, Minibuffer, Exiting, Top | |
6 | @chapter Basic Editing Commands | |
7 | ||
8 | @kindex C-h t | |
9 | @findex help-with-tutorial | |
10 | Here we explain the basics of how to enter text, make corrections, | |
11 | and save the text in a file. If this material is new to you, we | |
12 | suggest you first run the Emacs learn-by-doing tutorial, by typing | |
13 | @kbd{Control-h t} inside Emacs. (@code{help-with-tutorial}). | |
14 | ||
8cf51b2c GM |
15 | @menu |
16 | ||
17 | * Inserting Text:: Inserting text by simply typing it. | |
18 | * Moving Point:: Moving the cursor to the place where you want to | |
19 | change something. | |
20 | * Erasing:: Deleting and killing text. | |
21 | * Basic Undo:: Undoing recent changes in the text. | |
22 | * Files: Basic Files. Visiting, creating, and saving files. | |
23 | * Help: Basic Help. Asking what a character does. | |
24 | * Blank Lines:: Making and deleting blank lines. | |
25 | * Continuation Lines:: How Emacs displays lines too wide for the screen. | |
26 | * Position Info:: What page, line, row, or column is point on? | |
27 | * Arguments:: Numeric arguments for repeating a command N times. | |
28 | * Repeating:: Repeating the previous command quickly. | |
29 | @end menu | |
30 | ||
31 | @node Inserting Text | |
32 | @section Inserting Text | |
33 | ||
34 | @cindex insertion | |
35 | @cindex graphic characters | |
6c5f6319 CY |
36 | You can insert an ordinary @dfn{graphic character} (e.g., @samp{a}, |
37 | @samp{B}, @samp{3}, and @samp{=}) by typing the associated key. This | |
38 | adds the character to the buffer at point. Insertion moves point | |
39 | forward, so that point remains just after the inserted text. | |
40 | @xref{Point}. | |
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41 | |
42 | @kindex RET | |
43 | @cindex newline | |
6c5f6319 CY |
44 | To end a line and start a new one, type @key{RET}. This key may be |
45 | labeled @key{Return} or @key{Enter} on your keyboard, but we refer to | |
46 | it as @key{RET} in this manual. Pressing it inserts a newline | |
47 | character in the buffer. If point is at the end of the line, this | |
48 | creates a new blank line after it; if point is in the middle of a | |
49 | line, the line is split at that position. | |
50 | ||
51 | As we explain later in this manual, you can change the way Emacs | |
52 | handles text insertion by turning on @dfn{minor modes}. For instance, | |
53 | if you turn on a minor mode called @dfn{Auto Fill} mode, Emacs can | |
54 | split lines automatically when they become too long (@pxref{Filling}). | |
55 | If you turn on a minor mode called @dfn{Overwrite} mode, inserted | |
56 | characters replace (overwrite) existing text, instead of shoving it to | |
57 | the right. @xref{Minor Modes}. | |
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58 | |
59 | @cindex quoting | |
60 | @kindex C-q | |
61 | @findex quoted-insert | |
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62 | Only graphic characters can be inserted by typing the associated |
63 | key; other keys act as editing commands and do not insert themselves. | |
64 | For instance, @kbd{DEL} runs the command @code{delete-backward-char} | |
65 | by default (some modes bind it to a different command); it does not | |
66 | insert a literal @samp{DEL} character (@acronym{ASCII} character code | |
ad36c422 CY |
67 | 127). |
68 | ||
69 | To insert a non-graphic character, or a character that your keyboard | |
70 | does not support, first @dfn{quote} it by typing @kbd{C-q} | |
71 | (@code{quoted-insert}). There are two ways to use @kbd{C-q}: | |
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72 | |
73 | @itemize @bullet | |
74 | @item | |
75 | @kbd{C-q} followed by any non-graphic character (even @kbd{C-g}) | |
6c5f6319 CY |
76 | inserts that character. For instance, @kbd{C-q @key{DEL}} inserts a |
77 | literal @samp{DEL} character. | |
8cf51b2c GM |
78 | |
79 | @item | |
80 | @kbd{C-q} followed by a sequence of octal digits inserts the character | |
81 | with the specified octal character code. You can use any number of | |
82 | octal digits; any non-digit terminates the sequence. If the | |
83 | terminating character is @key{RET}, it serves only to terminate the | |
84 | sequence. Any other non-digit terminates the sequence and then acts | |
85 | as normal input---thus, @kbd{C-q 1 0 1 B} inserts @samp{AB}. | |
86 | ||
87 | The use of octal sequences is disabled in ordinary non-binary | |
88 | Overwrite mode, to give you a convenient way to insert a digit instead | |
89 | of overwriting with it. | |
90 | @end itemize | |
91 | ||
8cf51b2c | 92 | @vindex read-quoted-char-radix |
ad36c422 | 93 | @noindent |
8cf51b2c | 94 | To use decimal or hexadecimal instead of octal, set the variable |
ad36c422 CY |
95 | @code{read-quoted-char-radix} to 10 or 16. If the radix is greater |
96 | than 10, some letters starting with @kbd{a} serve as part of a | |
97 | character code, just like digits. | |
8cf51b2c | 98 | |
ad36c422 | 99 | A numeric argument tells @kbd{C-q} how many copies of the quoted |
8cf51b2c GM |
100 | character to insert (@pxref{Arguments}). |
101 | ||
ad36c422 CY |
102 | @findex ucs-insert |
103 | @cindex Unicode | |
104 | Instead of @kbd{C-q}, you can use @kbd{C-x 8 @key{RET}} | |
105 | (@code{ucs-insert}) to insert a character based on its Unicode name or | |
106 | code-point. This commands prompts for a character to insert, using | |
107 | the minibuffer; you can specify the character using either (i) the | |
108 | character's name in the Unicode standard, or (ii) the character's | |
109 | code-point in the Unicode standard. | |
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110 | |
111 | @node Moving Point | |
112 | @section Changing the Location of Point | |
113 | ||
114 | @cindex arrow keys | |
115 | @cindex moving point | |
116 | @cindex movement | |
117 | @cindex cursor motion | |
118 | @cindex moving the cursor | |
6c5f6319 CY |
119 | To do more than insert characters, you have to know how to move |
120 | point (@pxref{Point}). The keyboard commands @kbd{C-f}, @kbd{C-b}, | |
121 | @kbd{C-n}, and @kbd{C-p} move point to the right, left, up and down | |
122 | respectively. These are equivalent to the commands @kbd{@key{right}}, | |
123 | @kbd{@key{left}}, @kbd{@key{down}}, and @kbd{@key{up}}, entered using | |
124 | the @dfn{arrow keys} present on many keyboards. Many Emacs users find | |
125 | that it is slower to use the arrow keys than the equivalent control | |
126 | keys. You can also click the left mouse button to move point to the | |
127 | position clicked. Emacs also provides a variety of additional | |
128 | keyboard commands that move point in more sophisticated ways. | |
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129 | |
130 | @kindex C-a | |
131 | @kindex C-e | |
132 | @kindex C-f | |
133 | @kindex C-b | |
134 | @kindex C-n | |
135 | @kindex C-p | |
136 | @kindex M-> | |
137 | @kindex M-< | |
138 | @kindex M-r | |
139 | @kindex LEFT | |
140 | @kindex RIGHT | |
141 | @kindex UP | |
142 | @kindex DOWN | |
143 | @findex move-beginning-of-line | |
144 | @findex move-end-of-line | |
145 | @findex forward-char | |
146 | @findex backward-char | |
147 | @findex next-line | |
148 | @findex previous-line | |
149 | @findex beginning-of-buffer | |
150 | @findex end-of-buffer | |
151 | @findex goto-char | |
152 | @findex goto-line | |
153 | @findex move-to-window-line | |
154 | @table @kbd | |
155 | @item C-a | |
6c5f6319 | 156 | @itemx @key{Home} |
8cf51b2c GM |
157 | Move to the beginning of the line (@code{move-beginning-of-line}). |
158 | @item C-e | |
6c5f6319 | 159 | @itemx @key{End} |
8cf51b2c GM |
160 | Move to the end of the line (@code{move-end-of-line}). |
161 | @item C-f | |
6c5f6319 CY |
162 | @itemx @key{right} |
163 | Move forward one character (@code{forward-char}). | |
8cf51b2c | 164 | @item C-b |
6c5f6319 CY |
165 | @itemx @key{left} |
166 | Move backward one character (@code{backward-char}). | |
8cf51b2c | 167 | @item M-f |
6c5f6319 CY |
168 | @itemx M-@key{right} |
169 | @itemx C-@key{right} | |
8cf51b2c GM |
170 | Move forward one word (@code{forward-word}). |
171 | @item M-b | |
6c5f6319 CY |
172 | @itemx M-@key{left} |
173 | @itemx C-@key{left} | |
8cf51b2c GM |
174 | Move backward one word (@code{backward-word}). |
175 | @item C-n | |
6c5f6319 CY |
176 | @itemx @key{down} |
177 | Move down one screen line (@code{next-line}). This command attempts | |
178 | to keep the horizontal position unchanged, so if you start in the | |
179 | middle of one line, you move to the middle of the next. | |
8cf51b2c | 180 | @item C-p |
6c5f6319 CY |
181 | @itemx @key{up} |
182 | Move up one screen line (@code{previous-line}). This command | |
183 | preserves position within the line, like @kbd{C-n}. | |
8cf51b2c | 184 | @item M-r |
91ed7ea8 CY |
185 | Without moving the text on the screen, reposition point on the left |
186 | margin of the center-most text line of the window; on subsequent | |
187 | consecutive invocations, move point to the left margin of the top-most | |
188 | line, the bottom-most line, and so forth, in cyclic order | |
189 | (@code{move-to-window-line-top-bottom}). | |
190 | ||
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191 | A numeric argument says which screen line to place point on, counting |
192 | downward from the top of the window (zero means the top line). A | |
193 | negative argument counts lines up from the bottom (@minus{}1 means the | |
194 | bottom line). | |
91ed7ea8 | 195 | |
8cf51b2c GM |
196 | @item M-< |
197 | Move to the top of the buffer (@code{beginning-of-buffer}). With | |
198 | numeric argument @var{n}, move to @var{n}/10 of the way from the top. | |
199 | @xref{Arguments}, for more information on numeric arguments.@refill | |
200 | @item M-> | |
201 | Move to the end of the buffer (@code{end-of-buffer}). | |
202 | @item C-v | |
6c5f6319 | 203 | @itemx @key{PageDown} |
e2a71e28 | 204 | @itemx @key{next} |
8cf51b2c | 205 | Scroll the display one screen forward, and move point if necessary to |
6c5f6319 | 206 | put it on the screen (@code{scroll-up}). If your keyboard has a |
e2a71e28 | 207 | @key{PageDown} key (sometimes labelled @key{next}), it does the same |
867d4bb3 | 208 | thing as @key{C-v}. Scrolling commands are described further in |
6c5f6319 | 209 | @ref{Scrolling}. |
8cf51b2c | 210 | @item M-v |
6c5f6319 | 211 | @itemx @key{PageUp} |
e2a71e28 | 212 | @itemx @key{prior} |
8cf51b2c | 213 | Scroll one screen backward, and move point if necessary to put it on |
6c5f6319 | 214 | the screen (@code{scroll-down}). If your keyboard has a @key{PageUp} |
e2a71e28 | 215 | key (sometimes labelled @key{prior}), it does the same thing as |
b5700de6 | 216 | @kbd{M-v}. |
8cf51b2c GM |
217 | @item M-x goto-char |
218 | Read a number @var{n} and move point to buffer position @var{n}. | |
219 | Position 1 is the beginning of the buffer. | |
220 | @item M-g M-g | |
221 | @itemx M-g g | |
8cf51b2c | 222 | Read a number @var{n} and move point to the beginning of line number |
dd186936 LK |
223 | @var{n} (@code{goto-line}). Line 1 is the beginning of the buffer. If |
224 | point is on or just after a number in the buffer, that is the default | |
225 | for @var{n}. Just type @key{RET} in the minibuffer to use it. You can | |
226 | also specify @var{n} by giving @kbd{M-g M-g} a numeric prefix argument. | |
227 | @xref{Select Buffer}, for the behavior of @kbd{M-g M-g} when you give it | |
228 | a plain prefix argument. | |
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229 | @item C-x C-n |
230 | @findex set-goal-column | |
231 | @kindex C-x C-n | |
232 | Use the current column of point as the @dfn{semipermanent goal column} | |
233 | for @kbd{C-n} and @kbd{C-p} (@code{set-goal-column}). When a | |
234 | semipermanent goal column is in effect, those commands always try to | |
235 | move to this column, or as close as possible to it, after moving | |
236 | vertically. The goal column remains in effect until canceled. | |
237 | @item C-u C-x C-n | |
238 | Cancel the goal column. Henceforth, @kbd{C-n} and @kbd{C-p} try to | |
239 | preserve the horizontal position, as usual. | |
240 | @end table | |
241 | ||
6c5f6319 CY |
242 | @vindex line-move-visual |
243 | When a line of text in the buffer is longer than the width of the | |
244 | window, Emacs usually displays it on two or more @dfn{screen lines}. | |
245 | For convenience, @kbd{C-n} and @kbd{C-p} move point by screen lines, | |
246 | as do the equivalent keys @kbd{@key{down}} and @kbd{@key{up}}. You | |
247 | can force these commands to move according to @dfn{logical lines} | |
248 | (i.e., according to the text lines in the buffer) by setting the | |
249 | variable @code{line-move-visual} to @code{nil}; if a logical line | |
250 | occupies multiple screen lines, the cursor then skips over the | |
251 | additional screen lines. Moving by logical lines was the default | |
252 | behavior prior to Emacs 23.1. For details, see @ref{Continuation | |
253 | Lines}. @xref{Variables}, for how to set variables such as | |
254 | @code{line-move-visual}. | |
255 | ||
256 | Unlike @kbd{C-n} and @kbd{C-p}, most of the Emacs commands that work | |
257 | on lines work on @emph{logical} lines. For instance, @kbd{C-a} | |
258 | (@code{move-beginning-of-line}) and @kbd{C-e} | |
259 | (@code{move-end-of-line}) respectively move to the beginning and end | |
260 | of the logical line. Whenever we encounter commands that work on | |
261 | screen lines, such as @kbd{C-n} and @kbd{C-p}, we will point these | |
262 | out. | |
263 | ||
8cf51b2c | 264 | @vindex track-eol |
6c5f6319 CY |
265 | When @code{line-move-visual} is @code{nil}, you can also set the |
266 | variable @code{track-eol} to a non-@code{nil} value. Then @kbd{C-n} | |
267 | and @kbd{C-p}, when starting at the end of the logical line, move to | |
268 | the end of the next logical line. Normally, @code{track-eol} is | |
269 | @code{nil}. | |
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270 | |
271 | @vindex next-line-add-newlines | |
272 | @kbd{C-n} normally stops at the end of the buffer when you use it on | |
273 | the last line of the buffer. However, if you set the variable | |
274 | @code{next-line-add-newlines} to a non-@code{nil} value, @kbd{C-n} on | |
275 | the last line of a buffer creates an additional line at the end and | |
276 | moves down into it. | |
277 | ||
278 | @node Erasing | |
279 | @section Erasing Text | |
280 | ||
281 | @table @kbd | |
282 | @item @key{DEL} | |
6c5f6319 | 283 | @itemx @key{Backspace} |
8cf51b2c GM |
284 | Delete the character before point (@code{delete-backward-char}). |
285 | @item C-d | |
6c5f6319 | 286 | @itemx @key{Delete} |
8cf51b2c | 287 | Delete the character after point (@code{delete-char}). |
8cf51b2c GM |
288 | @item C-k |
289 | Kill to the end of the line (@code{kill-line}). | |
290 | @item M-d | |
291 | Kill forward to the end of the next word (@code{kill-word}). | |
292 | @item M-@key{DEL} | |
293 | Kill back to the beginning of the previous word | |
294 | (@code{backward-kill-word}). | |
295 | @end table | |
296 | ||
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297 | The key @kbd{@key{DEL}} (@code{delete-backward-char}) removes the |
298 | character before point, moving the cursor and all the characters after | |
299 | it backwards. On most keyboards, @key{DEL} is labelled | |
300 | @key{Backspace}, but we refer to it as @key{DEL} in this manual. Do | |
301 | not confuse @key{DEL} with another key, labelled @key{Delete}, that | |
302 | exists on many keyboards; we will discuss @key{Delete} momentarily. | |
303 | ||
304 | Typing @key{DEL} when the cursor is at the beginning of a line | |
305 | deletes the preceding newline character, joining the line with the one | |
306 | before it. | |
307 | ||
308 | On some text-only terminals, Emacs may not recognize the @key{DEL} | |
309 | key properly. If @key{DEL} does not do the right thing (e.g., if it | |
310 | deletes characters forwards), see @ref{DEL Does Not Delete}. | |
311 | ||
8cf51b2c GM |
312 | @cindex killing characters and lines |
313 | @cindex deleting characters and lines | |
314 | @cindex erasing characters and lines | |
6c5f6319 CY |
315 | The key @kbd{C-d} (@code{delete-char}) deletes the character after |
316 | point, i.e., the character under the cursor. This shifts the rest of | |
317 | the text on the line to the left. If you type @kbd{C-d} at the end of | |
318 | a line, it joins that line with the following line. This command is | |
319 | also bound to the key labelled @key{Delete} on many keyboards. | |
8cf51b2c GM |
320 | |
321 | To erase a larger amount of text, use the @kbd{C-k} key, which | |
322 | erases (kills) a line at a time. If you type @kbd{C-k} at the | |
323 | beginning or middle of a line, it kills all the text up to the end of | |
324 | the line. If you type @kbd{C-k} at the end of a line, it joins that | |
325 | line with the following line. | |
326 | ||
6c5f6319 | 327 | To learn more about killing text, see @ref{Killing}. |
8cf51b2c GM |
328 | |
329 | @node Basic Undo | |
330 | @section Undoing Changes | |
331 | ||
8cf51b2c | 332 | @table @kbd |
6c5f6319 | 333 | @item C-/ |
8cf51b2c GM |
334 | Undo one entry of the undo records---usually, one command worth |
335 | (@code{undo}). | |
6c5f6319 | 336 | @itemx C-x u |
8cf51b2c | 337 | @item C-_ |
8cf51b2c GM |
338 | The same. |
339 | @end table | |
340 | ||
6c5f6319 CY |
341 | Emacs records a list of changes made in the buffer text, so you can |
342 | undo recent changes. This is done using the @code{undo} command, | |
343 | which is bound to @kbd{C-/} (as well as @kbd{C-x u} and @kbd{C-_}). | |
344 | Normally, this command undoes the last change, moving point back to | |
345 | where it was before the change. The undo command applies only to | |
346 | changes in the buffer; you can't use it to undo cursor motion. | |
347 | ||
348 | Although each editing command usually makes a separate entry in the | |
349 | undo records, very simple commands may be grouped together. | |
350 | Sometimes, an entry may cover just part of a complex command. | |
8cf51b2c | 351 | |
6c5f6319 | 352 | If you repeat @kbd{C-/} (or its aliases), each repetition undoes |
8cf51b2c GM |
353 | another, earlier change, back to the limit of the undo information |
354 | available. If all recorded changes have already been undone, the undo | |
355 | command displays an error message and does nothing. | |
356 | ||
6c5f6319 | 357 | To learn more about the @code{undo} command, see @ref{Undo}. |
8cf51b2c GM |
358 | |
359 | @node Basic Files | |
360 | @section Files | |
361 | ||
362 | Text that you insert in an Emacs buffer lasts only as long as the | |
6c5f6319 | 363 | Emacs session. To keep any text permanently, you must put it in a |
8cf51b2c GM |
364 | @dfn{file}. Files are named units of text which are stored by the |
365 | operating system for you to retrieve later by name. To use the | |
6c5f6319 CY |
366 | contents of a file in any way, including editing it with Emacs, you |
367 | must specify the file name. | |
8cf51b2c GM |
368 | |
369 | Suppose there is a file named @file{test.emacs} in your home | |
370 | directory. To begin editing this file in Emacs, type | |
371 | ||
372 | @example | |
373 | C-x C-f test.emacs @key{RET} | |
374 | @end example | |
375 | ||
376 | @noindent | |
377 | Here the file name is given as an @dfn{argument} to the command @kbd{C-x | |
378 | C-f} (@code{find-file}). That command uses the @dfn{minibuffer} to | |
379 | read the argument, and you type @key{RET} to terminate the argument | |
380 | (@pxref{Minibuffer}). | |
381 | ||
382 | Emacs obeys this command by @dfn{visiting} the file: it creates a | |
6c5f6319 | 383 | buffer, copies the contents of the file into the buffer, and then |
8cf51b2c GM |
384 | displays the buffer for editing. If you alter the text, you can |
385 | @dfn{save} the new text in the file by typing @kbd{C-x C-s} | |
386 | (@code{save-buffer}). This copies the altered buffer contents back | |
387 | into the file @file{test.emacs}, making them permanent. Until you | |
388 | save, the changed text exists only inside Emacs, and the file | |
389 | @file{test.emacs} is unaltered. | |
390 | ||
391 | To create a file, just visit it with @kbd{C-x C-f} as if it already | |
392 | existed. This creates an empty buffer, in which you can insert the | |
393 | text you want to put in the file. Emacs actually creates the file the | |
394 | first time you save this buffer with @kbd{C-x C-s}. | |
395 | ||
396 | To learn more about using files in Emacs, see @ref{Files}. | |
397 | ||
398 | @node Basic Help | |
399 | @section Help | |
400 | ||
401 | @cindex getting help with keys | |
402 | If you forget what a key does, you can find out with the Help | |
403 | character, which is @kbd{C-h} (or @key{F1}, which is an alias for | |
6c5f6319 | 404 | @kbd{C-h}). Type @kbd{C-h k}, followed by the key of interest; for |
8cf51b2c GM |
405 | example, @kbd{C-h k C-n} tells you what @kbd{C-n} does. @kbd{C-h} is |
406 | a prefix key; @kbd{C-h k} is just one of its subcommands (the command | |
407 | @code{describe-key}). The other subcommands of @kbd{C-h} provide | |
408 | different kinds of help. Type @kbd{C-h} twice to get a description of | |
409 | all the help facilities. @xref{Help}. | |
410 | ||
411 | @node Blank Lines | |
412 | @section Blank Lines | |
413 | ||
414 | @cindex inserting blank lines | |
415 | @cindex deleting blank lines | |
416 | Here are special commands and techniques for inserting and deleting | |
417 | blank lines. | |
418 | ||
419 | @table @kbd | |
420 | @item C-o | |
6c5f6319 | 421 | Insert a blank line after the cursor (@code{open-line}). |
8cf51b2c GM |
422 | @item C-x C-o |
423 | Delete all but one of many consecutive blank lines | |
424 | (@code{delete-blank-lines}). | |
425 | @end table | |
426 | ||
427 | @kindex C-o | |
428 | @kindex C-x C-o | |
429 | @cindex blank lines | |
430 | @findex open-line | |
431 | @findex delete-blank-lines | |
6c5f6319 CY |
432 | We have seen how @kbd{@key{RET}} (@code{newline}) starts a new line |
433 | of text. However, it may be easier to see what you are doing if you | |
434 | first make a blank line and then insert the desired text into it. | |
435 | This is easy to do using the key @kbd{C-o} (@code{open-line}), which | |
436 | inserts a newline after point but leaves point in front of the | |
437 | newline. After @kbd{C-o}, type the text for the new line. | |
8cf51b2c GM |
438 | |
439 | You can make several blank lines by typing @kbd{C-o} several times, or | |
440 | by giving it a numeric argument specifying how many blank lines to make. | |
441 | @xref{Arguments}, for how. If you have a fill prefix, the @kbd{C-o} | |
442 | command inserts the fill prefix on the new line, if typed at the | |
443 | beginning of a line. @xref{Fill Prefix}. | |
444 | ||
445 | The easy way to get rid of extra blank lines is with the command | |
6c5f6319 CY |
446 | @kbd{C-x C-o} (@code{delete-blank-lines}). If point lies within a run |
447 | of several blank lines, @kbd{C-x C-o} deletes all but one of them. If | |
448 | point is on a single blank line, @kbd{C-x C-o} deletes it. If point | |
449 | is on a nonblank line, @kbd{C-x C-o} deletes all following blank | |
450 | lines, if any exists. | |
8cf51b2c GM |
451 | |
452 | @node Continuation Lines | |
453 | @section Continuation Lines | |
454 | ||
455 | @cindex continuation line | |
456 | @cindex wrapping | |
457 | @cindex line wrapping | |
458 | @cindex fringes, and continuation lines | |
6c5f6319 CY |
459 | Sometimes, a line of text in the buffer---a @dfn{logical line}---is |
460 | too long to fit in the window, and Emacs displays it as two or more | |
461 | @dfn{screen lines}. This is called @dfn{line wrapping} or | |
462 | @dfn{continuation}, and the long logical line is called a | |
463 | @dfn{continued line}. On a graphical display, Emacs indicates line | |
464 | wrapping with small bent arrows in the left and right window fringes. | |
465 | On a text-only terminal, Emacs indicates line wrapping by displaying a | |
466 | @samp{\} character at the right margin. | |
467 | ||
468 | Most commands that act on lines act on logical lines, not screen | |
469 | lines. For instance, @kbd{C-k} kills a logical line. As described | |
470 | earlier, @kbd{C-n} (@code{next-line}) and @kbd{C-p} | |
471 | (@code{previous-line}) are special exceptions: they move point down | |
472 | and up, respectively, by one screen line (@pxref{Moving Point}). | |
8cf51b2c GM |
473 | |
474 | @cindex truncation | |
475 | @cindex line truncation, and fringes | |
6c5f6319 CY |
476 | Emacs can optionally @dfn{truncate} long logical lines instead of |
477 | continuing them. This means that every logical line occupies a single | |
478 | screen line; if it is longer than the width of the window, the rest of | |
479 | the line is not displayed. On a graphical display, a truncated line | |
480 | is indicated by a small straight arrow in the right fringe; on a | |
481 | text-only terminal, it is indicated by a @samp{$} character in the | |
482 | right margin. @xref{Line Truncation}. | |
483 | ||
484 | By default, continued lines are wrapped at the right window edge. | |
485 | Since the wrapping may occur in the middle of a word, continued lines | |
486 | can be difficult to read. The usual solution is to break your lines | |
487 | before they get too long, by inserting newlines. If you prefer, you | |
488 | can make Emacs insert a newline automatically when a line gets too | |
489 | long, by using Auto Fill mode. @xref{Filling}. | |
490 | ||
491 | @cindex word wrap | |
492 | Sometimes, you may need to edit files containing many long logical | |
493 | lines, and it may not be practical to break them all up by adding | |
494 | newlines. In that case, you can use Visual Line mode, which enables | |
495 | @dfn{word wrapping}: instead of wrapping long lines exactly at the | |
496 | right window edge, Emacs wraps them at the word boundaries (i.e., | |
497 | space or tab characters) nearest to the right window edge. Visual | |
498 | Line mode also redefines editing commands such as @code{C-a}, | |
499 | @code{C-n}, and @code{C-k} to operate on screen lines rather than | |
500 | logical lines. @xref{Visual Line Mode}. | |
8cf51b2c GM |
501 | |
502 | @node Position Info | |
503 | @section Cursor Position Information | |
504 | ||
505 | Here are commands to get information about the size and position of | |
506 | parts of the buffer, and to count lines. | |
507 | ||
508 | @table @kbd | |
509 | @item M-x what-page | |
510 | Display the page number of point, and the line number within that page. | |
511 | @item M-x what-line | |
512 | Display the line number of point in the whole buffer. | |
513 | @item M-x line-number-mode | |
514 | @itemx M-x column-number-mode | |
515 | Toggle automatic display of the current line number or column number. | |
516 | @xref{Optional Mode Line}. | |
f0d129c6 GM |
517 | @item M-x count-lines-region |
518 | Display the number of lines in the current region. Normally bound to | |
519 | @kbd{M-=}, except in a few specialist modes. @xref{Mark}, for | |
520 | information about the region. | |
8cf51b2c GM |
521 | @item C-x = |
522 | Display the character code of character after point, character position of | |
523 | point, and column of point (@code{what-cursor-position}). | |
524 | @item M-x hl-line-mode | |
525 | Enable or disable highlighting of the current line. @xref{Cursor | |
526 | Display}. | |
527 | @item M-x size-indication-mode | |
528 | Toggle automatic display of the size of the buffer. | |
529 | @xref{Optional Mode Line}. | |
530 | @end table | |
531 | ||
532 | @findex what-page | |
533 | @findex what-line | |
534 | @cindex line number commands | |
535 | @cindex location of point | |
536 | @cindex cursor location | |
537 | @cindex point location | |
6c5f6319 CY |
538 | @kbd{M-x what-line} displays the current line number in the echo |
539 | area. This command is usually redundant, because the current line | |
540 | number is shown in the mode line (@pxref{Mode Line}). However, if you | |
867d4bb3 | 541 | narrow the buffer, the mode line shows the line number relative to |
6c5f6319 CY |
542 | the accessible portion (@pxref{Narrowing}). By contrast, |
543 | @code{what-line} displays both the line number relative to the | |
544 | narrowed region and the line number relative to the whole buffer. | |
8cf51b2c GM |
545 | |
546 | @kbd{M-x what-page} counts pages from the beginning of the file, and | |
547 | counts lines within the page, showing both numbers in the echo area. | |
548 | @xref{Pages}. | |
549 | ||
550 | @kindex M-= | |
551 | @findex count-lines-region | |
f0d129c6 GM |
552 | Use @kbd{M-x count-lines-region} (normally bound to @kbd{M-=}) to |
553 | display the number of lines in the region (@pxref{Mark}). @xref{Pages}, | |
554 | for the command @kbd{C-x l} which counts the lines in the current page. | |
8cf51b2c GM |
555 | |
556 | @kindex C-x = | |
557 | @findex what-cursor-position | |
6c5f6319 CY |
558 | The command @kbd{C-x =} (@code{what-cursor-position}) shows |
559 | information about the current cursor position and the buffer contents | |
560 | at that position. It displays a line in the echo area that looks like | |
561 | this: | |
8cf51b2c GM |
562 | |
563 | @smallexample | |
564 | Char: c (99, #o143, #x63) point=28062 of 36168 (78%) column=53 | |
565 | @end smallexample | |
566 | ||
6c5f6319 CY |
567 | After @samp{Char:}, this shows the character in the buffer at point. |
568 | The text inside the parenthesis shows the corresponding decimal, octal | |
569 | and hex character codes; for more information about how @kbd{C-x =} | |
570 | displays character information, see @ref{International Chars}. After | |
571 | @samp{point=} is the position of point as a character count (the first | |
572 | character in the buffer is position 1, the second character is | |
573 | position 2, and so on). The number after that is the total number of | |
574 | characters in the buffer, and the number in parenthesis expresses the | |
575 | position as a percentage of the total. After @samp{column=} is the | |
576 | horizontal position of point, in columns counting from the left edge | |
577 | of the window. | |
8cf51b2c GM |
578 | |
579 | If the buffer has been narrowed, making some of the text at the | |
580 | beginning and the end temporarily inaccessible, @kbd{C-x =} displays | |
6c5f6319 CY |
581 | additional text describing the currently accessible range. For |
582 | example, it might display this: | |
8cf51b2c GM |
583 | |
584 | @smallexample | |
585 | Char: C (67, #o103, #x43) point=252 of 889 (28%) <231-599> column=0 | |
586 | @end smallexample | |
587 | ||
588 | @noindent | |
589 | where the two extra numbers give the smallest and largest character | |
6c5f6319 CY |
590 | position that point is allowed to assume. The characters between |
591 | those two positions are the accessible ones. @xref{Narrowing}. | |
8cf51b2c GM |
592 | |
593 | @node Arguments | |
594 | @section Numeric Arguments | |
595 | @cindex numeric arguments | |
596 | @cindex prefix arguments | |
597 | @cindex arguments to commands | |
598 | ||
6c5f6319 CY |
599 | In the terminology of mathematics and computing, @dfn{argument} |
600 | means ``data provided to a function or operation.'' You can give any | |
601 | Emacs command a @dfn{numeric argument} (also called a @dfn{prefix | |
602 | argument}). Some commands interpret the argument as a repetition | |
603 | count. For example, giving @kbd{C-f} an argument of ten causes it to | |
604 | move point forward by ten characters instead of one. With these | |
605 | commands, no argument is equivalent to an argument of one, and | |
606 | negative arguments cause them to move or act in the opposite | |
607 | direction. | |
8cf51b2c GM |
608 | |
609 | @kindex M-1 | |
610 | @kindex M-@t{-} | |
611 | @findex digit-argument | |
612 | @findex negative-argument | |
fcda6454 | 613 | The easiest way to specify a numeric argument is to type a digit |
6c5f6319 CY |
614 | and/or a minus sign while holding down the @key{META} key. For |
615 | example, | |
8cf51b2c GM |
616 | |
617 | @example | |
618 | M-5 C-n | |
619 | @end example | |
620 | ||
621 | @noindent | |
6c5f6319 CY |
622 | moves down five lines. The keys @kbd{M-1}, @kbd{M-2}, and so on, as |
623 | well as @kbd{M--}, are bound to commands (@code{digit-argument} and | |
624 | @code{negative-argument}) that set up an argument for the next | |
625 | command. @kbd{Meta--} without digits normally means @minus{}1. | |
8cf51b2c | 626 | |
fcda6454 CY |
627 | If you enter more than one digit, you need not hold down the |
628 | @key{META} key for the second and subsequent digits. Thus, to move | |
629 | down fifty lines, type | |
630 | ||
631 | @example | |
632 | M-5 0 C-n | |
633 | @end example | |
634 | ||
635 | @noindent | |
636 | Note that this @emph{does not} insert five copies of @samp{0} and move | |
637 | down one line, as you might expect---the @samp{0} is treated as part | |
638 | of the prefix argument. | |
639 | ||
640 | (What if you do want to insert five copies of @samp{0}? Type @kbd{M-5 | |
641 | C-u 0}. Here, @kbd{C-u} ``terminates'' the prefix argument, so that | |
642 | the next keystroke begins the command that you want to execute. Note | |
643 | that this meaning of @kbd{C-u} applies only to this case. For the | |
644 | usual role of @kbd{C-u}, see below.) | |
645 | ||
8cf51b2c GM |
646 | @kindex C-u |
647 | @findex universal-argument | |
fcda6454 CY |
648 | Instead of typing @kbd{M-1}, @kbd{M-2}, and so on, another way to |
649 | specify a numeric argument is to type @kbd{C-u} | |
650 | (@code{universal-argument}) followed by some digits, or (for a | |
651 | negative argument) a minus sign followed by digits. A minus sign | |
652 | without digits normally means @minus{}1. | |
6c5f6319 CY |
653 | |
654 | @kbd{C-u} alone has the special meaning of ``four times'': it | |
655 | multiplies the argument for the next command by four. @kbd{C-u C-u} | |
656 | multiplies it by sixteen. Thus, @kbd{C-u C-u C-f} moves forward | |
657 | sixteen characters. Other useful combinations are @kbd{C-u C-n}, | |
658 | @kbd{C-u C-u C-n} (move down a good fraction of a screen), @kbd{C-u | |
659 | C-u C-o} (make ``a lot'' of blank lines), and @kbd{C-u C-k} (kill four | |
660 | lines). | |
661 | ||
662 | You can use a numeric argument before a self-inserting character to | |
663 | insert multiple copies of it. This is straightforward when the | |
664 | character is not a digit; for example, @kbd{C-u 6 4 a} inserts 64 | |
665 | copies of the character @samp{a}. But this does not work for | |
666 | inserting digits; @kbd{C-u 6 4 1} specifies an argument of 641. You | |
667 | can separate the argument from the digit to insert with another | |
668 | @kbd{C-u}; for example, @kbd{C-u 6 4 C-u 1} does insert 64 copies of | |
669 | the character @samp{1}. | |
8cf51b2c GM |
670 | |
671 | Some commands care whether there is an argument, but ignore its | |
f0a35bd4 | 672 | value. For example, the command @kbd{M-q} (@code{fill-paragraph}) |
8cf51b2c | 673 | fills text; with an argument, it justifies the text as well. |
6c5f6319 CY |
674 | (@xref{Filling}, for more information on @kbd{M-q}.) For these |
675 | commands, it is enough to the argument with a single @kbd{C-u}. | |
676 | ||
677 | Some commands use the value of the argument as a repeat count, but | |
678 | do something special when there is no argument. For example, the | |
679 | command @kbd{C-k} (@code{kill-line}) with argument @var{n} kills | |
680 | @var{n} lines, including their terminating newlines. But @kbd{C-k} | |
681 | with no argument is special: it kills the text up to the next newline, | |
682 | or, if point is right at the end of the line, it kills the newline | |
683 | itself. Thus, two @kbd{C-k} commands with no arguments can kill a | |
684 | nonblank line, just like @kbd{C-k} with an argument of one. | |
685 | (@xref{Killing}, for more information on @kbd{C-k}.) | |
8cf51b2c GM |
686 | |
687 | A few commands treat a plain @kbd{C-u} differently from an ordinary | |
688 | argument. A few others may treat an argument of just a minus sign | |
689 | differently from an argument of @minus{}1. These unusual cases are | |
690 | described when they come up; they exist to make an individual command | |
691 | more convenient, and they are documented in that command's | |
692 | documentation string. | |
693 | ||
8cf51b2c GM |
694 | We use the term ``prefix argument'' as well as ``numeric argument,'' |
695 | to emphasize that you type these argument before the command, and to | |
696 | distinguish them from minibuffer arguments that come after the | |
697 | command. | |
698 | ||
699 | @node Repeating | |
700 | @section Repeating a Command | |
701 | @cindex repeating a command | |
702 | ||
703 | Many simple commands, such as those invoked with a single key or | |
704 | with @kbd{M-x @var{command-name} @key{RET}}, can be repeated by | |
705 | invoking them with a numeric argument that serves as a repeat count | |
706 | (@pxref{Arguments}). However, if the command you want to repeat | |
707 | prompts for input, or uses a numeric argument in another way, that | |
708 | method won't work. | |
709 | ||
710 | @kindex C-x z | |
711 | @findex repeat | |
712 | The command @kbd{C-x z} (@code{repeat}) provides another way to repeat | |
713 | an Emacs command many times. This command repeats the previous Emacs | |
714 | command, whatever that was. Repeating a command uses the same arguments | |
715 | that were used before; it does not read new arguments each time. | |
716 | ||
717 | To repeat the command more than once, type additional @kbd{z}'s: each | |
718 | @kbd{z} repeats the command one more time. Repetition ends when you | |
719 | type a character other than @kbd{z}, or press a mouse button. | |
720 | ||
721 | For example, suppose you type @kbd{C-u 2 0 C-d} to delete 20 | |
722 | characters. You can repeat that command (including its argument) three | |
723 | additional times, to delete a total of 80 characters, by typing @kbd{C-x | |
724 | z z z}. The first @kbd{C-x z} repeats the command once, and each | |
725 | subsequent @kbd{z} repeats it once again. | |
726 | ||
727 | @ignore | |
728 | arch-tag: cda8952a-c439-41c1-aecf-4bc0d6482956 | |
729 | @end ignore |