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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, | |
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3 | @c 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
4 | @c Free Software Foundation, Inc. | |
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5 | @c See file emacs.texi for copying conditions. |
6 | @node Basic, Minibuffer, Exiting, Top | |
7 | @chapter Basic Editing Commands | |
8 | ||
9 | @kindex C-h t | |
10 | @findex help-with-tutorial | |
11 | Here we explain the basics of how to enter text, make corrections, | |
12 | and save the text in a file. If this material is new to you, we | |
13 | suggest you first run the Emacs learn-by-doing tutorial, by typing | |
14 | @kbd{Control-h t} inside Emacs. (@code{help-with-tutorial}). | |
15 | ||
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16 | @menu |
17 | ||
18 | * Inserting Text:: Inserting text by simply typing it. | |
19 | * Moving Point:: Moving the cursor to the place where you want to | |
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20 | change something. |
21 | * Erasing:: Deleting and killing text. | |
22 | * Basic Undo:: Undoing recent changes in the text. | |
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23 | * Files: Basic Files. Visiting, creating, and saving files. |
24 | * Help: Basic Help. Asking what a character does. | |
8838673e | 25 | * Blank Lines:: Making and deleting blank lines. |
8cf51b2c GM |
26 | * Continuation Lines:: How Emacs displays lines too wide for the screen. |
27 | * Position Info:: What page, line, row, or column is point on? | |
8838673e | 28 | * Arguments:: Numeric arguments for repeating a command N times. |
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29 | * Repeating:: Repeating the previous command quickly. |
30 | @end menu | |
31 | ||
32 | @node Inserting Text | |
33 | @section Inserting Text | |
34 | ||
35 | @cindex insertion | |
36 | @cindex graphic characters | |
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37 | You can insert an ordinary @dfn{graphic character} (e.g., @samp{a}, |
38 | @samp{B}, @samp{3}, and @samp{=}) by typing the associated key. This | |
39 | adds the character to the buffer at point. Insertion moves point | |
40 | forward, so that point remains just after the inserted text. | |
41 | @xref{Point}. | |
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42 | |
43 | @kindex RET | |
44 | @cindex newline | |
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45 | To end a line and start a new one, type @key{RET}. This key may be |
46 | labeled @key{Return} or @key{Enter} on your keyboard, but we refer to | |
47 | it as @key{RET} in this manual. Pressing it inserts a newline | |
48 | character in the buffer. If point is at the end of the line, this | |
49 | creates a new blank line after it; if point is in the middle of a | |
50 | line, the line is split at that position. | |
51 | ||
52 | As we explain later in this manual, you can change the way Emacs | |
53 | handles text insertion by turning on @dfn{minor modes}. For instance, | |
54 | if you turn on a minor mode called @dfn{Auto Fill} mode, Emacs can | |
55 | split lines automatically when they become too long (@pxref{Filling}). | |
56 | If you turn on a minor mode called @dfn{Overwrite} mode, inserted | |
57 | characters replace (overwrite) existing text, instead of shoving it to | |
58 | the right. @xref{Minor Modes}. | |
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59 | |
60 | @cindex quoting | |
61 | @kindex C-q | |
62 | @findex quoted-insert | |
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63 | Only graphic characters can be inserted by typing the associated |
64 | key; other keys act as editing commands and do not insert themselves. | |
65 | For instance, @kbd{DEL} runs the command @code{delete-backward-char} | |
66 | by default (some modes bind it to a different command); it does not | |
67 | insert a literal @samp{DEL} character (@acronym{ASCII} character code | |
ad36c422 CY |
68 | 127). |
69 | ||
70 | To insert a non-graphic character, or a character that your keyboard | |
71 | does not support, first @dfn{quote} it by typing @kbd{C-q} | |
72 | (@code{quoted-insert}). There are two ways to use @kbd{C-q}: | |
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73 | |
74 | @itemize @bullet | |
75 | @item | |
76 | @kbd{C-q} followed by any non-graphic character (even @kbd{C-g}) | |
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77 | inserts that character. For instance, @kbd{C-q @key{DEL}} inserts a |
78 | literal @samp{DEL} character. | |
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79 | |
80 | @item | |
81 | @kbd{C-q} followed by a sequence of octal digits inserts the character | |
82 | with the specified octal character code. You can use any number of | |
83 | octal digits; any non-digit terminates the sequence. If the | |
84 | terminating character is @key{RET}, it serves only to terminate the | |
85 | sequence. Any other non-digit terminates the sequence and then acts | |
86 | as normal input---thus, @kbd{C-q 1 0 1 B} inserts @samp{AB}. | |
87 | ||
88 | The use of octal sequences is disabled in ordinary non-binary | |
89 | Overwrite mode, to give you a convenient way to insert a digit instead | |
90 | of overwriting with it. | |
91 | @end itemize | |
92 | ||
8cf51b2c | 93 | @vindex read-quoted-char-radix |
ad36c422 | 94 | @noindent |
8cf51b2c | 95 | To use decimal or hexadecimal instead of octal, set the variable |
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96 | @code{read-quoted-char-radix} to 10 or 16. If the radix is 16, |
97 | the letters @kbd{a} to @kbd{f} serve as part of a character code, | |
98 | just like digits. Case is ignored. | |
8cf51b2c | 99 | |
ad36c422 | 100 | A numeric argument tells @kbd{C-q} how many copies of the quoted |
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101 | character to insert (@pxref{Arguments}). |
102 | ||
ad36c422 | 103 | @findex ucs-insert |
ce79424f | 104 | @kindex C-x 8 RET |
ad36c422 CY |
105 | @cindex Unicode |
106 | Instead of @kbd{C-q}, you can use @kbd{C-x 8 @key{RET}} | |
107 | (@code{ucs-insert}) to insert a character based on its Unicode name or | |
04d3bb6c | 108 | code-point. This command prompts for a character to insert, using |
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109 | the minibuffer; you can specify the character using either (i) the |
110 | character's name in the Unicode standard, or (ii) the character's | |
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111 | code-point in the Unicode standard. If you specify the character's |
112 | name, the command provides completion. | |
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113 | |
114 | @node Moving Point | |
115 | @section Changing the Location of Point | |
116 | ||
117 | @cindex arrow keys | |
118 | @cindex moving point | |
119 | @cindex movement | |
120 | @cindex cursor motion | |
121 | @cindex moving the cursor | |
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122 | To do more than insert characters, you have to know how to move |
123 | point (@pxref{Point}). The keyboard commands @kbd{C-f}, @kbd{C-b}, | |
124 | @kbd{C-n}, and @kbd{C-p} move point to the right, left, up and down | |
125 | respectively. These are equivalent to the commands @kbd{@key{right}}, | |
126 | @kbd{@key{left}}, @kbd{@key{down}}, and @kbd{@key{up}}, entered using | |
127 | the @dfn{arrow keys} present on many keyboards. Many Emacs users find | |
128 | that it is slower to use the arrow keys than the equivalent control | |
129 | keys. You can also click the left mouse button to move point to the | |
130 | position clicked. Emacs also provides a variety of additional | |
131 | keyboard commands that move point in more sophisticated ways. | |
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132 | |
133 | @kindex C-a | |
134 | @kindex C-e | |
135 | @kindex C-f | |
136 | @kindex C-b | |
137 | @kindex C-n | |
138 | @kindex C-p | |
139 | @kindex M-> | |
140 | @kindex M-< | |
141 | @kindex M-r | |
142 | @kindex LEFT | |
143 | @kindex RIGHT | |
144 | @kindex UP | |
145 | @kindex DOWN | |
146 | @findex move-beginning-of-line | |
147 | @findex move-end-of-line | |
148 | @findex forward-char | |
149 | @findex backward-char | |
150 | @findex next-line | |
151 | @findex previous-line | |
152 | @findex beginning-of-buffer | |
153 | @findex end-of-buffer | |
154 | @findex goto-char | |
155 | @findex goto-line | |
156 | @findex move-to-window-line | |
157 | @table @kbd | |
158 | @item C-a | |
6c5f6319 | 159 | @itemx @key{Home} |
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160 | Move to the beginning of the line (@code{move-beginning-of-line}). |
161 | @item C-e | |
6c5f6319 | 162 | @itemx @key{End} |
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163 | Move to the end of the line (@code{move-end-of-line}). |
164 | @item C-f | |
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165 | @itemx @key{right} |
166 | Move forward one character (@code{forward-char}). | |
8cf51b2c | 167 | @item C-b |
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168 | @itemx @key{left} |
169 | Move backward one character (@code{backward-char}). | |
8cf51b2c | 170 | @item M-f |
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171 | @itemx M-@key{right} |
172 | @itemx C-@key{right} | |
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173 | Move forward one word (@code{forward-word}). |
174 | @item M-b | |
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175 | @itemx M-@key{left} |
176 | @itemx C-@key{left} | |
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177 | Move backward one word (@code{backward-word}). |
178 | @item C-n | |
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179 | @itemx @key{down} |
180 | Move down one screen line (@code{next-line}). This command attempts | |
181 | to keep the horizontal position unchanged, so if you start in the | |
182 | middle of one line, you move to the middle of the next. | |
8cf51b2c | 183 | @item C-p |
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184 | @itemx @key{up} |
185 | Move up one screen line (@code{previous-line}). This command | |
186 | preserves position within the line, like @kbd{C-n}. | |
8cf51b2c | 187 | @item M-r |
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188 | Without moving the text on the screen, reposition point on the left |
189 | margin of the center-most text line of the window; on subsequent | |
190 | consecutive invocations, move point to the left margin of the top-most | |
191 | line, the bottom-most line, and so forth, in cyclic order | |
192 | (@code{move-to-window-line-top-bottom}). | |
193 | ||
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194 | A numeric argument says which screen line to place point on, counting |
195 | downward from the top of the window (zero means the top line). A | |
196 | negative argument counts lines up from the bottom (@minus{}1 means the | |
197 | bottom line). | |
91ed7ea8 | 198 | |
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199 | @item M-< |
200 | Move to the top of the buffer (@code{beginning-of-buffer}). With | |
201 | numeric argument @var{n}, move to @var{n}/10 of the way from the top. | |
202 | @xref{Arguments}, for more information on numeric arguments.@refill | |
203 | @item M-> | |
204 | Move to the end of the buffer (@code{end-of-buffer}). | |
205 | @item C-v | |
6c5f6319 | 206 | @itemx @key{PageDown} |
e2a71e28 | 207 | @itemx @key{next} |
8cf51b2c | 208 | Scroll the display one screen forward, and move point if necessary to |
6c5f6319 | 209 | put it on the screen (@code{scroll-up}). If your keyboard has a |
e2a71e28 | 210 | @key{PageDown} key (sometimes labelled @key{next}), it does the same |
867d4bb3 | 211 | thing as @key{C-v}. Scrolling commands are described further in |
6c5f6319 | 212 | @ref{Scrolling}. |
8cf51b2c | 213 | @item M-v |
6c5f6319 | 214 | @itemx @key{PageUp} |
e2a71e28 | 215 | @itemx @key{prior} |
8cf51b2c | 216 | Scroll one screen backward, and move point if necessary to put it on |
6c5f6319 | 217 | the screen (@code{scroll-down}). If your keyboard has a @key{PageUp} |
e2a71e28 | 218 | key (sometimes labelled @key{prior}), it does the same thing as |
b5700de6 | 219 | @kbd{M-v}. |
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220 | @item M-x goto-char |
221 | Read a number @var{n} and move point to buffer position @var{n}. | |
222 | Position 1 is the beginning of the buffer. | |
223 | @item M-g M-g | |
224 | @itemx M-g g | |
8cf51b2c | 225 | Read a number @var{n} and move point to the beginning of line number |
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226 | @var{n} (@code{goto-line}). Line 1 is the beginning of the buffer. If |
227 | point is on or just after a number in the buffer, that is the default | |
228 | for @var{n}. Just type @key{RET} in the minibuffer to use it. You can | |
229 | also specify @var{n} by giving @kbd{M-g M-g} a numeric prefix argument. | |
230 | @xref{Select Buffer}, for the behavior of @kbd{M-g M-g} when you give it | |
231 | a plain prefix argument. | |
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232 | @item C-x C-n |
233 | @findex set-goal-column | |
234 | @kindex C-x C-n | |
235 | Use the current column of point as the @dfn{semipermanent goal column} | |
236 | for @kbd{C-n} and @kbd{C-p} (@code{set-goal-column}). When a | |
237 | semipermanent goal column is in effect, those commands always try to | |
238 | move to this column, or as close as possible to it, after moving | |
239 | vertically. The goal column remains in effect until canceled. | |
240 | @item C-u C-x C-n | |
241 | Cancel the goal column. Henceforth, @kbd{C-n} and @kbd{C-p} try to | |
242 | preserve the horizontal position, as usual. | |
243 | @end table | |
244 | ||
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245 | @vindex line-move-visual |
246 | When a line of text in the buffer is longer than the width of the | |
247 | window, Emacs usually displays it on two or more @dfn{screen lines}. | |
248 | For convenience, @kbd{C-n} and @kbd{C-p} move point by screen lines, | |
249 | as do the equivalent keys @kbd{@key{down}} and @kbd{@key{up}}. You | |
250 | can force these commands to move according to @dfn{logical lines} | |
251 | (i.e., according to the text lines in the buffer) by setting the | |
252 | variable @code{line-move-visual} to @code{nil}; if a logical line | |
253 | occupies multiple screen lines, the cursor then skips over the | |
254 | additional screen lines. Moving by logical lines was the default | |
255 | behavior prior to Emacs 23.1. For details, see @ref{Continuation | |
256 | Lines}. @xref{Variables}, for how to set variables such as | |
257 | @code{line-move-visual}. | |
258 | ||
259 | Unlike @kbd{C-n} and @kbd{C-p}, most of the Emacs commands that work | |
260 | on lines work on @emph{logical} lines. For instance, @kbd{C-a} | |
261 | (@code{move-beginning-of-line}) and @kbd{C-e} | |
262 | (@code{move-end-of-line}) respectively move to the beginning and end | |
263 | of the logical line. Whenever we encounter commands that work on | |
264 | screen lines, such as @kbd{C-n} and @kbd{C-p}, we will point these | |
265 | out. | |
266 | ||
8cf51b2c | 267 | @vindex track-eol |
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268 | When @code{line-move-visual} is @code{nil}, you can also set the |
269 | variable @code{track-eol} to a non-@code{nil} value. Then @kbd{C-n} | |
270 | and @kbd{C-p}, when starting at the end of the logical line, move to | |
271 | the end of the next logical line. Normally, @code{track-eol} is | |
272 | @code{nil}. | |
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273 | |
274 | @vindex next-line-add-newlines | |
275 | @kbd{C-n} normally stops at the end of the buffer when you use it on | |
276 | the last line of the buffer. However, if you set the variable | |
277 | @code{next-line-add-newlines} to a non-@code{nil} value, @kbd{C-n} on | |
278 | the last line of a buffer creates an additional line at the end and | |
279 | moves down into it. | |
280 | ||
281 | @node Erasing | |
282 | @section Erasing Text | |
283 | ||
284 | @table @kbd | |
285 | @item @key{DEL} | |
6c5f6319 | 286 | @itemx @key{Backspace} |
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287 | Delete the character before point (@code{delete-backward-char}). |
288 | @item C-d | |
6c5f6319 | 289 | @itemx @key{Delete} |
8cf51b2c | 290 | Delete the character after point (@code{delete-char}). |
8cf51b2c GM |
291 | @item C-k |
292 | Kill to the end of the line (@code{kill-line}). | |
293 | @item M-d | |
294 | Kill forward to the end of the next word (@code{kill-word}). | |
295 | @item M-@key{DEL} | |
296 | Kill back to the beginning of the previous word | |
297 | (@code{backward-kill-word}). | |
298 | @end table | |
299 | ||
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300 | The key @kbd{@key{DEL}} (@code{delete-backward-char}) removes the |
301 | character before point, moving the cursor and all the characters after | |
302 | it backwards. On most keyboards, @key{DEL} is labelled | |
303 | @key{Backspace}, but we refer to it as @key{DEL} in this manual. Do | |
304 | not confuse @key{DEL} with another key, labelled @key{Delete}, that | |
305 | exists on many keyboards; we will discuss @key{Delete} momentarily. | |
306 | ||
307 | Typing @key{DEL} when the cursor is at the beginning of a line | |
308 | deletes the preceding newline character, joining the line with the one | |
309 | before it. | |
310 | ||
311 | On some text-only terminals, Emacs may not recognize the @key{DEL} | |
312 | key properly. If @key{DEL} does not do the right thing (e.g., if it | |
313 | deletes characters forwards), see @ref{DEL Does Not Delete}. | |
314 | ||
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315 | @cindex killing characters and lines |
316 | @cindex deleting characters and lines | |
317 | @cindex erasing characters and lines | |
6c5f6319 CY |
318 | The key @kbd{C-d} (@code{delete-char}) deletes the character after |
319 | point, i.e., the character under the cursor. This shifts the rest of | |
320 | the text on the line to the left. If you type @kbd{C-d} at the end of | |
321 | a line, it joins that line with the following line. This command is | |
322 | also bound to the key labelled @key{Delete} on many keyboards. | |
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323 | |
324 | To erase a larger amount of text, use the @kbd{C-k} key, which | |
325 | erases (kills) a line at a time. If you type @kbd{C-k} at the | |
326 | beginning or middle of a line, it kills all the text up to the end of | |
327 | the line. If you type @kbd{C-k} at the end of a line, it joins that | |
328 | line with the following line. | |
329 | ||
6c5f6319 | 330 | To learn more about killing text, see @ref{Killing}. |
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331 | |
332 | @node Basic Undo | |
333 | @section Undoing Changes | |
334 | ||
8cf51b2c | 335 | @table @kbd |
6c5f6319 | 336 | @item C-/ |
8cf51b2c GM |
337 | Undo one entry of the undo records---usually, one command worth |
338 | (@code{undo}). | |
6c5f6319 | 339 | @itemx C-x u |
8cf51b2c | 340 | @item C-_ |
8cf51b2c GM |
341 | The same. |
342 | @end table | |
343 | ||
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344 | Emacs records a list of changes made in the buffer text, so you can |
345 | undo recent changes. This is done using the @code{undo} command, | |
346 | which is bound to @kbd{C-/} (as well as @kbd{C-x u} and @kbd{C-_}). | |
347 | Normally, this command undoes the last change, moving point back to | |
348 | where it was before the change. The undo command applies only to | |
349 | changes in the buffer; you can't use it to undo cursor motion. | |
350 | ||
351 | Although each editing command usually makes a separate entry in the | |
352 | undo records, very simple commands may be grouped together. | |
353 | Sometimes, an entry may cover just part of a complex command. | |
8cf51b2c | 354 | |
6c5f6319 | 355 | If you repeat @kbd{C-/} (or its aliases), each repetition undoes |
8cf51b2c GM |
356 | another, earlier change, back to the limit of the undo information |
357 | available. If all recorded changes have already been undone, the undo | |
358 | command displays an error message and does nothing. | |
359 | ||
6c5f6319 | 360 | To learn more about the @code{undo} command, see @ref{Undo}. |
8cf51b2c GM |
361 | |
362 | @node Basic Files | |
363 | @section Files | |
364 | ||
365 | Text that you insert in an Emacs buffer lasts only as long as the | |
6c5f6319 | 366 | Emacs session. To keep any text permanently, you must put it in a |
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367 | @dfn{file}. Files are named units of text which are stored by the |
368 | operating system for you to retrieve later by name. To use the | |
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369 | contents of a file in any way, including editing it with Emacs, you |
370 | must specify the file name. | |
8cf51b2c GM |
371 | |
372 | Suppose there is a file named @file{test.emacs} in your home | |
373 | directory. To begin editing this file in Emacs, type | |
374 | ||
375 | @example | |
376 | C-x C-f test.emacs @key{RET} | |
377 | @end example | |
378 | ||
379 | @noindent | |
380 | Here the file name is given as an @dfn{argument} to the command @kbd{C-x | |
381 | C-f} (@code{find-file}). That command uses the @dfn{minibuffer} to | |
382 | read the argument, and you type @key{RET} to terminate the argument | |
383 | (@pxref{Minibuffer}). | |
384 | ||
385 | Emacs obeys this command by @dfn{visiting} the file: it creates a | |
6c5f6319 | 386 | buffer, copies the contents of the file into the buffer, and then |
8cf51b2c GM |
387 | displays the buffer for editing. If you alter the text, you can |
388 | @dfn{save} the new text in the file by typing @kbd{C-x C-s} | |
389 | (@code{save-buffer}). This copies the altered buffer contents back | |
390 | into the file @file{test.emacs}, making them permanent. Until you | |
391 | save, the changed text exists only inside Emacs, and the file | |
392 | @file{test.emacs} is unaltered. | |
393 | ||
394 | To create a file, just visit it with @kbd{C-x C-f} as if it already | |
395 | existed. This creates an empty buffer, in which you can insert the | |
396 | text you want to put in the file. Emacs actually creates the file the | |
397 | first time you save this buffer with @kbd{C-x C-s}. | |
398 | ||
399 | To learn more about using files in Emacs, see @ref{Files}. | |
400 | ||
401 | @node Basic Help | |
402 | @section Help | |
403 | ||
404 | @cindex getting help with keys | |
405 | If you forget what a key does, you can find out with the Help | |
406 | character, which is @kbd{C-h} (or @key{F1}, which is an alias for | |
6c5f6319 | 407 | @kbd{C-h}). Type @kbd{C-h k}, followed by the key of interest; for |
8cf51b2c GM |
408 | example, @kbd{C-h k C-n} tells you what @kbd{C-n} does. @kbd{C-h} is |
409 | a prefix key; @kbd{C-h k} is just one of its subcommands (the command | |
410 | @code{describe-key}). The other subcommands of @kbd{C-h} provide | |
411 | different kinds of help. Type @kbd{C-h} twice to get a description of | |
412 | all the help facilities. @xref{Help}. | |
413 | ||
414 | @node Blank Lines | |
415 | @section Blank Lines | |
416 | ||
417 | @cindex inserting blank lines | |
418 | @cindex deleting blank lines | |
419 | Here are special commands and techniques for inserting and deleting | |
420 | blank lines. | |
421 | ||
422 | @table @kbd | |
423 | @item C-o | |
6c5f6319 | 424 | Insert a blank line after the cursor (@code{open-line}). |
8cf51b2c GM |
425 | @item C-x C-o |
426 | Delete all but one of many consecutive blank lines | |
427 | (@code{delete-blank-lines}). | |
428 | @end table | |
429 | ||
430 | @kindex C-o | |
431 | @kindex C-x C-o | |
432 | @cindex blank lines | |
433 | @findex open-line | |
434 | @findex delete-blank-lines | |
6c5f6319 CY |
435 | We have seen how @kbd{@key{RET}} (@code{newline}) starts a new line |
436 | of text. However, it may be easier to see what you are doing if you | |
437 | first make a blank line and then insert the desired text into it. | |
438 | This is easy to do using the key @kbd{C-o} (@code{open-line}), which | |
439 | inserts a newline after point but leaves point in front of the | |
440 | newline. After @kbd{C-o}, type the text for the new line. | |
8cf51b2c GM |
441 | |
442 | You can make several blank lines by typing @kbd{C-o} several times, or | |
443 | by giving it a numeric argument specifying how many blank lines to make. | |
444 | @xref{Arguments}, for how. If you have a fill prefix, the @kbd{C-o} | |
445 | command inserts the fill prefix on the new line, if typed at the | |
446 | beginning of a line. @xref{Fill Prefix}. | |
447 | ||
448 | The easy way to get rid of extra blank lines is with the command | |
6c5f6319 CY |
449 | @kbd{C-x C-o} (@code{delete-blank-lines}). If point lies within a run |
450 | of several blank lines, @kbd{C-x C-o} deletes all but one of them. If | |
451 | point is on a single blank line, @kbd{C-x C-o} deletes it. If point | |
452 | is on a nonblank line, @kbd{C-x C-o} deletes all following blank | |
453 | lines, if any exists. | |
8cf51b2c GM |
454 | |
455 | @node Continuation Lines | |
456 | @section Continuation Lines | |
457 | ||
458 | @cindex continuation line | |
459 | @cindex wrapping | |
460 | @cindex line wrapping | |
461 | @cindex fringes, and continuation lines | |
6c5f6319 CY |
462 | Sometimes, a line of text in the buffer---a @dfn{logical line}---is |
463 | too long to fit in the window, and Emacs displays it as two or more | |
464 | @dfn{screen lines}. This is called @dfn{line wrapping} or | |
465 | @dfn{continuation}, and the long logical line is called a | |
466 | @dfn{continued line}. On a graphical display, Emacs indicates line | |
467 | wrapping with small bent arrows in the left and right window fringes. | |
468 | On a text-only terminal, Emacs indicates line wrapping by displaying a | |
469 | @samp{\} character at the right margin. | |
470 | ||
471 | Most commands that act on lines act on logical lines, not screen | |
472 | lines. For instance, @kbd{C-k} kills a logical line. As described | |
473 | earlier, @kbd{C-n} (@code{next-line}) and @kbd{C-p} | |
474 | (@code{previous-line}) are special exceptions: they move point down | |
475 | and up, respectively, by one screen line (@pxref{Moving Point}). | |
8cf51b2c GM |
476 | |
477 | @cindex truncation | |
478 | @cindex line truncation, and fringes | |
6c5f6319 CY |
479 | Emacs can optionally @dfn{truncate} long logical lines instead of |
480 | continuing them. This means that every logical line occupies a single | |
481 | screen line; if it is longer than the width of the window, the rest of | |
482 | the line is not displayed. On a graphical display, a truncated line | |
483 | is indicated by a small straight arrow in the right fringe; on a | |
484 | text-only terminal, it is indicated by a @samp{$} character in the | |
485 | right margin. @xref{Line Truncation}. | |
486 | ||
487 | By default, continued lines are wrapped at the right window edge. | |
488 | Since the wrapping may occur in the middle of a word, continued lines | |
489 | can be difficult to read. The usual solution is to break your lines | |
490 | before they get too long, by inserting newlines. If you prefer, you | |
491 | can make Emacs insert a newline automatically when a line gets too | |
492 | long, by using Auto Fill mode. @xref{Filling}. | |
493 | ||
494 | @cindex word wrap | |
495 | Sometimes, you may need to edit files containing many long logical | |
496 | lines, and it may not be practical to break them all up by adding | |
497 | newlines. In that case, you can use Visual Line mode, which enables | |
498 | @dfn{word wrapping}: instead of wrapping long lines exactly at the | |
499 | right window edge, Emacs wraps them at the word boundaries (i.e., | |
500 | space or tab characters) nearest to the right window edge. Visual | |
501 | Line mode also redefines editing commands such as @code{C-a}, | |
502 | @code{C-n}, and @code{C-k} to operate on screen lines rather than | |
503 | logical lines. @xref{Visual Line Mode}. | |
8cf51b2c GM |
504 | |
505 | @node Position Info | |
506 | @section Cursor Position Information | |
507 | ||
508 | Here are commands to get information about the size and position of | |
509 | parts of the buffer, and to count lines. | |
510 | ||
511 | @table @kbd | |
512 | @item M-x what-page | |
513 | Display the page number of point, and the line number within that page. | |
514 | @item M-x what-line | |
515 | Display the line number of point in the whole buffer. | |
516 | @item M-x line-number-mode | |
517 | @itemx M-x column-number-mode | |
518 | Toggle automatic display of the current line number or column number. | |
519 | @xref{Optional Mode Line}. | |
f0d129c6 GM |
520 | @item M-x count-lines-region |
521 | Display the number of lines in the current region. Normally bound to | |
522 | @kbd{M-=}, except in a few specialist modes. @xref{Mark}, for | |
523 | information about the region. | |
8cf51b2c GM |
524 | @item C-x = |
525 | Display the character code of character after point, character position of | |
526 | point, and column of point (@code{what-cursor-position}). | |
527 | @item M-x hl-line-mode | |
528 | Enable or disable highlighting of the current line. @xref{Cursor | |
529 | Display}. | |
530 | @item M-x size-indication-mode | |
531 | Toggle automatic display of the size of the buffer. | |
532 | @xref{Optional Mode Line}. | |
533 | @end table | |
534 | ||
535 | @findex what-page | |
536 | @findex what-line | |
537 | @cindex line number commands | |
538 | @cindex location of point | |
539 | @cindex cursor location | |
540 | @cindex point location | |
6c5f6319 CY |
541 | @kbd{M-x what-line} displays the current line number in the echo |
542 | area. This command is usually redundant, because the current line | |
543 | number is shown in the mode line (@pxref{Mode Line}). However, if you | |
867d4bb3 | 544 | narrow the buffer, the mode line shows the line number relative to |
6c5f6319 CY |
545 | the accessible portion (@pxref{Narrowing}). By contrast, |
546 | @code{what-line} displays both the line number relative to the | |
547 | narrowed region and the line number relative to the whole buffer. | |
8cf51b2c GM |
548 | |
549 | @kbd{M-x what-page} counts pages from the beginning of the file, and | |
550 | counts lines within the page, showing both numbers in the echo area. | |
551 | @xref{Pages}. | |
552 | ||
553 | @kindex M-= | |
554 | @findex count-lines-region | |
f0d129c6 GM |
555 | Use @kbd{M-x count-lines-region} (normally bound to @kbd{M-=}) to |
556 | display the number of lines in the region (@pxref{Mark}). @xref{Pages}, | |
557 | for the command @kbd{C-x l} which counts the lines in the current page. | |
8cf51b2c GM |
558 | |
559 | @kindex C-x = | |
560 | @findex what-cursor-position | |
6c5f6319 CY |
561 | The command @kbd{C-x =} (@code{what-cursor-position}) shows |
562 | information about the current cursor position and the buffer contents | |
563 | at that position. It displays a line in the echo area that looks like | |
564 | this: | |
8cf51b2c GM |
565 | |
566 | @smallexample | |
567 | Char: c (99, #o143, #x63) point=28062 of 36168 (78%) column=53 | |
568 | @end smallexample | |
569 | ||
6c5f6319 CY |
570 | After @samp{Char:}, this shows the character in the buffer at point. |
571 | The text inside the parenthesis shows the corresponding decimal, octal | |
572 | and hex character codes; for more information about how @kbd{C-x =} | |
573 | displays character information, see @ref{International Chars}. After | |
574 | @samp{point=} is the position of point as a character count (the first | |
575 | character in the buffer is position 1, the second character is | |
576 | position 2, and so on). The number after that is the total number of | |
577 | characters in the buffer, and the number in parenthesis expresses the | |
578 | position as a percentage of the total. After @samp{column=} is the | |
579 | horizontal position of point, in columns counting from the left edge | |
580 | of the window. | |
8cf51b2c GM |
581 | |
582 | If the buffer has been narrowed, making some of the text at the | |
583 | beginning and the end temporarily inaccessible, @kbd{C-x =} displays | |
6c5f6319 CY |
584 | additional text describing the currently accessible range. For |
585 | example, it might display this: | |
8cf51b2c GM |
586 | |
587 | @smallexample | |
588 | Char: C (67, #o103, #x43) point=252 of 889 (28%) <231-599> column=0 | |
589 | @end smallexample | |
590 | ||
591 | @noindent | |
592 | where the two extra numbers give the smallest and largest character | |
6c5f6319 CY |
593 | position that point is allowed to assume. The characters between |
594 | those two positions are the accessible ones. @xref{Narrowing}. | |
8cf51b2c GM |
595 | |
596 | @node Arguments | |
597 | @section Numeric Arguments | |
598 | @cindex numeric arguments | |
599 | @cindex prefix arguments | |
600 | @cindex arguments to commands | |
601 | ||
6c5f6319 CY |
602 | In the terminology of mathematics and computing, @dfn{argument} |
603 | means ``data provided to a function or operation.'' You can give any | |
604 | Emacs command a @dfn{numeric argument} (also called a @dfn{prefix | |
605 | argument}). Some commands interpret the argument as a repetition | |
606 | count. For example, giving @kbd{C-f} an argument of ten causes it to | |
607 | move point forward by ten characters instead of one. With these | |
608 | commands, no argument is equivalent to an argument of one, and | |
609 | negative arguments cause them to move or act in the opposite | |
610 | direction. | |
8cf51b2c GM |
611 | |
612 | @kindex M-1 | |
613 | @kindex M-@t{-} | |
614 | @findex digit-argument | |
615 | @findex negative-argument | |
fcda6454 | 616 | The easiest way to specify a numeric argument is to type a digit |
6c5f6319 CY |
617 | and/or a minus sign while holding down the @key{META} key. For |
618 | example, | |
8cf51b2c GM |
619 | |
620 | @example | |
621 | M-5 C-n | |
622 | @end example | |
623 | ||
624 | @noindent | |
6c5f6319 CY |
625 | moves down five lines. The keys @kbd{M-1}, @kbd{M-2}, and so on, as |
626 | well as @kbd{M--}, are bound to commands (@code{digit-argument} and | |
627 | @code{negative-argument}) that set up an argument for the next | |
628 | command. @kbd{Meta--} without digits normally means @minus{}1. | |
8cf51b2c | 629 | |
fcda6454 CY |
630 | If you enter more than one digit, you need not hold down the |
631 | @key{META} key for the second and subsequent digits. Thus, to move | |
632 | down fifty lines, type | |
633 | ||
634 | @example | |
635 | M-5 0 C-n | |
636 | @end example | |
637 | ||
638 | @noindent | |
639 | Note that this @emph{does not} insert five copies of @samp{0} and move | |
640 | down one line, as you might expect---the @samp{0} is treated as part | |
641 | of the prefix argument. | |
642 | ||
643 | (What if you do want to insert five copies of @samp{0}? Type @kbd{M-5 | |
644 | C-u 0}. Here, @kbd{C-u} ``terminates'' the prefix argument, so that | |
645 | the next keystroke begins the command that you want to execute. Note | |
646 | that this meaning of @kbd{C-u} applies only to this case. For the | |
647 | usual role of @kbd{C-u}, see below.) | |
648 | ||
8cf51b2c GM |
649 | @kindex C-u |
650 | @findex universal-argument | |
fcda6454 CY |
651 | Instead of typing @kbd{M-1}, @kbd{M-2}, and so on, another way to |
652 | specify a numeric argument is to type @kbd{C-u} | |
653 | (@code{universal-argument}) followed by some digits, or (for a | |
654 | negative argument) a minus sign followed by digits. A minus sign | |
655 | without digits normally means @minus{}1. | |
6c5f6319 CY |
656 | |
657 | @kbd{C-u} alone has the special meaning of ``four times'': it | |
658 | multiplies the argument for the next command by four. @kbd{C-u C-u} | |
659 | multiplies it by sixteen. Thus, @kbd{C-u C-u C-f} moves forward | |
660 | sixteen characters. Other useful combinations are @kbd{C-u C-n}, | |
661 | @kbd{C-u C-u C-n} (move down a good fraction of a screen), @kbd{C-u | |
662 | C-u C-o} (make ``a lot'' of blank lines), and @kbd{C-u C-k} (kill four | |
663 | lines). | |
664 | ||
665 | You can use a numeric argument before a self-inserting character to | |
666 | insert multiple copies of it. This is straightforward when the | |
667 | character is not a digit; for example, @kbd{C-u 6 4 a} inserts 64 | |
668 | copies of the character @samp{a}. But this does not work for | |
669 | inserting digits; @kbd{C-u 6 4 1} specifies an argument of 641. You | |
670 | can separate the argument from the digit to insert with another | |
671 | @kbd{C-u}; for example, @kbd{C-u 6 4 C-u 1} does insert 64 copies of | |
672 | the character @samp{1}. | |
8cf51b2c GM |
673 | |
674 | Some commands care whether there is an argument, but ignore its | |
f0a35bd4 | 675 | value. For example, the command @kbd{M-q} (@code{fill-paragraph}) |
8cf51b2c | 676 | fills text; with an argument, it justifies the text as well. |
6c5f6319 CY |
677 | (@xref{Filling}, for more information on @kbd{M-q}.) For these |
678 | commands, it is enough to the argument with a single @kbd{C-u}. | |
679 | ||
680 | Some commands use the value of the argument as a repeat count, but | |
681 | do something special when there is no argument. For example, the | |
682 | command @kbd{C-k} (@code{kill-line}) with argument @var{n} kills | |
683 | @var{n} lines, including their terminating newlines. But @kbd{C-k} | |
684 | with no argument is special: it kills the text up to the next newline, | |
685 | or, if point is right at the end of the line, it kills the newline | |
686 | itself. Thus, two @kbd{C-k} commands with no arguments can kill a | |
687 | nonblank line, just like @kbd{C-k} with an argument of one. | |
688 | (@xref{Killing}, for more information on @kbd{C-k}.) | |
8cf51b2c GM |
689 | |
690 | A few commands treat a plain @kbd{C-u} differently from an ordinary | |
691 | argument. A few others may treat an argument of just a minus sign | |
692 | differently from an argument of @minus{}1. These unusual cases are | |
693 | described when they come up; they exist to make an individual command | |
694 | more convenient, and they are documented in that command's | |
695 | documentation string. | |
696 | ||
8cf51b2c GM |
697 | We use the term ``prefix argument'' as well as ``numeric argument,'' |
698 | to emphasize that you type these argument before the command, and to | |
699 | distinguish them from minibuffer arguments that come after the | |
700 | command. | |
701 | ||
702 | @node Repeating | |
703 | @section Repeating a Command | |
704 | @cindex repeating a command | |
705 | ||
706 | Many simple commands, such as those invoked with a single key or | |
707 | with @kbd{M-x @var{command-name} @key{RET}}, can be repeated by | |
708 | invoking them with a numeric argument that serves as a repeat count | |
709 | (@pxref{Arguments}). However, if the command you want to repeat | |
710 | prompts for input, or uses a numeric argument in another way, that | |
711 | method won't work. | |
712 | ||
713 | @kindex C-x z | |
714 | @findex repeat | |
715 | The command @kbd{C-x z} (@code{repeat}) provides another way to repeat | |
716 | an Emacs command many times. This command repeats the previous Emacs | |
717 | command, whatever that was. Repeating a command uses the same arguments | |
718 | that were used before; it does not read new arguments each time. | |
719 | ||
720 | To repeat the command more than once, type additional @kbd{z}'s: each | |
721 | @kbd{z} repeats the command one more time. Repetition ends when you | |
722 | type a character other than @kbd{z}, or press a mouse button. | |
723 | ||
724 | For example, suppose you type @kbd{C-u 2 0 C-d} to delete 20 | |
725 | characters. You can repeat that command (including its argument) three | |
726 | additional times, to delete a total of 80 characters, by typing @kbd{C-x | |
727 | z z z}. The first @kbd{C-x z} repeats the command once, and each | |
728 | subsequent @kbd{z} repeats it once again. | |
729 | ||
730 | @ignore | |
731 | arch-tag: cda8952a-c439-41c1-aecf-4bc0d6482956 | |
732 | @end ignore |