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8cf51b2c | 1 | @c This is part of the Emacs manual. |
73b0cd50 | 2 | @c Copyright (C) 1985-1987, 1993-1995, 1997, 2000-2011 |
04d3bb6c | 3 | @c 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 | |
de0bde62 | 13 | @kbd{C-h t} (@code{help-with-tutorial}). |
8cf51b2c | 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 | |
8838673e GM |
19 | change something. |
20 | * Erasing:: Deleting and killing text. | |
21 | * Basic Undo:: Undoing recent changes in the text. | |
8cf51b2c GM |
22 | * Files: Basic Files. Visiting, creating, and saving files. |
23 | * Help: Basic Help. Asking what a character does. | |
8838673e | 24 | * Blank Lines:: Making and deleting blank lines. |
8cf51b2c | 25 | * Continuation Lines:: How Emacs displays lines too wide for the screen. |
b2b0776e | 26 | * Position Info:: What line, row, or column is point on? |
8838673e | 27 | * Arguments:: Numeric arguments for repeating a command N times. |
8cf51b2c GM |
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}. | |
8cf51b2c GM |
41 | |
42 | @kindex RET | |
43 | @cindex newline | |
de0bde62 CY |
44 | To end a line and start a new one, type @key{RET} (@code{newline}). |
45 | (The @key{RET} key may be labeled @key{Return} or @key{Enter} on your | |
46 | keyboard, but we refer to it as @key{RET} in this manual.) This | |
47 | command inserts a newline character into the buffer. If point is at | |
48 | the end of the line, the effect is to create a new blank line after | |
49 | it; if point is in the middle of a line, the line is split at that | |
50 | position. | |
6c5f6319 CY |
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, | |
de0bde62 CY |
54 | the minor mode called Auto Fill mode splits lines automatically when |
55 | they get too long (@pxref{Filling}). The minor mode called Overwrite | |
56 | mode causes inserted characters to replace (overwrite) existing text, | |
57 | instead of shoving it to the right. @xref{Minor Modes}. | |
8cf51b2c GM |
58 | |
59 | @cindex quoting | |
60 | @kindex C-q | |
61 | @findex quoted-insert | |
6c5f6319 CY |
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 | |
de0bde62 CY |
83 | terminating character is @key{RET}, that @key{RET} serves only to |
84 | terminate the sequence. Any other non-digit terminates the sequence | |
85 | and then acts as normal input---thus, @kbd{C-q 1 0 1 B} inserts | |
86 | @samp{AB}. | |
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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 |
103dd3a8 GM |
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 | @findex ucs-insert |
ce79424f | 101 | @kindex C-x 8 RET |
69b8be97 EZ |
102 | @cindex Unicode characters, inserting |
103 | @cindex insert Unicode character | |
104 | @cindex characters, inserting by name or code-point | |
de0bde62 CY |
105 | Instead of @kbd{C-q}, you can use the command @kbd{C-x 8 @key{RET}} |
106 | (@code{ucs-insert}). This prompts for the Unicode name or code-point | |
107 | of a character, using the minibuffer. If you enter a name, the | |
108 | command provides completion (@pxref{Completion}). If you enter a | |
109 | code-point, it should be a hexadecimal number (which is the convention | |
110 | for Unicode). The command then inserts the corresponding character | |
111 | into the buffer. For example, both of the following insert the | |
d366bd53 | 112 | infinity sign (Unicode code-point @code{U+221E}): |
de0bde62 CY |
113 | |
114 | @example | |
115 | @kbd{C-x 8 @key{RET} infinity @key{RET}} | |
116 | @kbd{C-x 8 @key{RET} 221e @key{RET}} | |
117 | @end example | |
118 | ||
119 | A numeric argument to either @kbd{C-q} or @kbd{C-x 8 @key{RET}} | |
120 | specifies how many copies of the character to insert | |
121 | (@pxref{Arguments}). | |
8cf51b2c GM |
122 | |
123 | @node Moving Point | |
124 | @section Changing the Location of Point | |
125 | ||
126 | @cindex arrow keys | |
127 | @cindex moving point | |
128 | @cindex movement | |
129 | @cindex cursor motion | |
130 | @cindex moving the cursor | |
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131 | To do more than insert characters, you have to know how to move |
132 | point (@pxref{Point}). The keyboard commands @kbd{C-f}, @kbd{C-b}, | |
133 | @kbd{C-n}, and @kbd{C-p} move point to the right, left, up and down | |
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134 | respectively. You can also move point using the @dfn{arrow keys} |
135 | present on most keyboards: @kbd{@key{right}}, @kbd{@key{left}}, | |
136 | @kbd{@key{down}}, and @kbd{@key{up}}; however, many Emacs users find | |
137 | that it is slower to use the arrow keys than the control keys. | |
138 | ||
139 | You can also click the left mouse button to move point to the | |
6c5f6319 CY |
140 | position clicked. Emacs also provides a variety of additional |
141 | keyboard commands that move point in more sophisticated ways. | |
8cf51b2c | 142 | |
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143 | @table @kbd |
144 | ||
145 | @item C-f | |
8cf51b2c | 146 | @kindex C-f |
8cf51b2c | 147 | @findex forward-char |
de0bde62 CY |
148 | Move forward one character (@code{forward-char}). |
149 | ||
150 | @item @key{right} | |
151 | @kindex RIGHT | |
db5dce9d | 152 | @findex right-char |
de0bde62 CY |
153 | This command (@code{right-char}) behaves like @kbd{C-f}, with one |
154 | exception: when editing right-to-left scripts such as Arabic, it | |
155 | instead moves @emph{backward} if the current paragraph is a | |
156 | right-to-left paragraph. @xref{Bidirectional Editing}. | |
157 | ||
158 | @item C-b | |
159 | @kindex C-b | |
160 | @findex backward-char | |
161 | Move backward one character (@code{backward-char}). | |
162 | ||
163 | @item @key{left} | |
164 | @kindex LEFT | |
db5dce9d | 165 | @findex left-char |
de0bde62 CY |
166 | This command (@code{left-char}) behaves like @kbd{C-b}, except it |
167 | moves @emph{forward} if the current paragraph is right-to-left. | |
168 | @xref{Bidirectional Editing}. | |
169 | ||
170 | @item C-n | |
171 | @itemx @key{down} | |
172 | @kindex C-n | |
173 | @kindex DOWN | |
8cf51b2c | 174 | @findex next-line |
de0bde62 CY |
175 | Move down one screen line (@code{next-line}). This command attempts |
176 | to keep the horizontal position unchanged, so if you start in the | |
177 | middle of one line, you move to the middle of the next. | |
178 | ||
179 | @item C-p | |
180 | @itemx @key{up} | |
181 | @kindex C-p | |
182 | @kindex UP | |
8cf51b2c | 183 | @findex previous-line |
de0bde62 CY |
184 | Move up one screen line (@code{previous-line}). This command |
185 | preserves position within the line, like @kbd{C-n}. | |
186 | ||
8cf51b2c | 187 | @item C-a |
6c5f6319 | 188 | @itemx @key{Home} |
de0bde62 CY |
189 | @kindex C-a |
190 | @kindex HOME | |
191 | @findex move-beginning-of-line | |
8cf51b2c | 192 | Move to the beginning of the line (@code{move-beginning-of-line}). |
de0bde62 | 193 | |
8cf51b2c | 194 | @item C-e |
6c5f6319 | 195 | @itemx @key{End} |
de0bde62 CY |
196 | @kindex C-e |
197 | @kindex END | |
198 | @findex move-end-of-line | |
8cf51b2c | 199 | Move to the end of the line (@code{move-end-of-line}). |
de0bde62 | 200 | |
8cf51b2c | 201 | @item M-f |
de0bde62 CY |
202 | @kindex M-f |
203 | @findex forward-word | |
8cf51b2c | 204 | Move forward one word (@code{forward-word}). |
de0bde62 | 205 | |
db5dce9d | 206 | @item C-@key{right} |
de0bde62 CY |
207 | @itemx M-@key{right} |
208 | @kindex C-RIGHT | |
209 | @kindex M-RIGHT | |
210 | @findex right-word | |
211 | This command (@code{right-word}) behaves like @kbd{M-f}, except it | |
212 | moves @emph{backward} by one word if the current paragraph is | |
213 | right-to-left. @xref{Bidirectional Editing}. | |
214 | ||
8cf51b2c | 215 | @item M-b |
de0bde62 CY |
216 | @kindex M-b |
217 | @findex backward-word | |
8cf51b2c | 218 | Move backward one word (@code{backward-word}). |
de0bde62 | 219 | |
db5dce9d | 220 | @item C-@key{left} |
de0bde62 CY |
221 | @itemx M-@key{left} |
222 | @kindex C-LEFT | |
223 | @kindex M-LEFT | |
224 | @findex left-word | |
225 | This command (@code{left-word}) behaves like @kbd{M-f}, except it | |
226 | moves @emph{forward} by one word if the current paragraph is | |
227 | right-to-left. @xref{Bidirectional Editing}. | |
228 | ||
8cf51b2c | 229 | @item M-r |
de0bde62 CY |
230 | @kindex M-r |
231 | @findex move-to-window-line-top-bottom | |
91ed7ea8 CY |
232 | Without moving the text on the screen, reposition point on the left |
233 | margin of the center-most text line of the window; on subsequent | |
234 | consecutive invocations, move point to the left margin of the top-most | |
235 | line, the bottom-most line, and so forth, in cyclic order | |
236 | (@code{move-to-window-line-top-bottom}). | |
237 | ||
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238 | A numeric argument says which screen line to place point on, counting |
239 | downward from the top of the window (zero means the top line). A | |
240 | negative argument counts lines up from the bottom (@minus{}1 means the | |
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241 | bottom line). @xref{Arguments}, for more information on numeric |
242 | arguments. | |
91ed7ea8 | 243 | |
8cf51b2c | 244 | @item M-< |
de0bde62 CY |
245 | @kindex M-< |
246 | @findex beginning-of-buffer | |
8cf51b2c GM |
247 | Move to the top of the buffer (@code{beginning-of-buffer}). With |
248 | numeric argument @var{n}, move to @var{n}/10 of the way from the top. | |
de0bde62 | 249 | |
8cf51b2c | 250 | @item M-> |
de0bde62 CY |
251 | @kindex M-> |
252 | @findex end-of-buffer | |
8cf51b2c | 253 | Move to the end of the buffer (@code{end-of-buffer}). |
550f41cd | 254 | |
8cf51b2c | 255 | @item C-v |
6c5f6319 | 256 | @itemx @key{PageDown} |
e2a71e28 | 257 | @itemx @key{next} |
550f41cd CY |
258 | Scroll the display one screen forward, and move point onscreen if |
259 | necessary (@code{scroll-up-command}). @xref{Scrolling}. | |
260 | ||
8cf51b2c | 261 | @item M-v |
6c5f6319 | 262 | @itemx @key{PageUp} |
e2a71e28 | 263 | @itemx @key{prior} |
550f41cd CY |
264 | Scroll one screen backward, and move point onscreen if necessary |
265 | (@code{scroll-down-command}). @xref{Scrolling}. | |
266 | ||
8cf51b2c | 267 | @item M-x goto-char |
de0bde62 | 268 | @findex goto-char |
8cf51b2c GM |
269 | Read a number @var{n} and move point to buffer position @var{n}. |
270 | Position 1 is the beginning of the buffer. | |
de0bde62 | 271 | |
8cf51b2c GM |
272 | @item M-g M-g |
273 | @itemx M-g g | |
de0bde62 CY |
274 | @kindex M-g M-g |
275 | @kindex M-g g | |
276 | @findex goto-line | |
8cf51b2c | 277 | Read a number @var{n} and move point to the beginning of line number |
dd186936 LK |
278 | @var{n} (@code{goto-line}). Line 1 is the beginning of the buffer. If |
279 | point is on or just after a number in the buffer, that is the default | |
280 | for @var{n}. Just type @key{RET} in the minibuffer to use it. You can | |
281 | also specify @var{n} by giving @kbd{M-g M-g} a numeric prefix argument. | |
282 | @xref{Select Buffer}, for the behavior of @kbd{M-g M-g} when you give it | |
283 | a plain prefix argument. | |
de0bde62 | 284 | |
8cf51b2c | 285 | @item C-x C-n |
8cf51b2c | 286 | @kindex C-x C-n |
de0bde62 | 287 | @findex set-goal-column |
8cf51b2c GM |
288 | Use the current column of point as the @dfn{semipermanent goal column} |
289 | for @kbd{C-n} and @kbd{C-p} (@code{set-goal-column}). When a | |
290 | semipermanent goal column is in effect, those commands always try to | |
291 | move to this column, or as close as possible to it, after moving | |
292 | vertically. The goal column remains in effect until canceled. | |
de0bde62 | 293 | |
8cf51b2c GM |
294 | @item C-u C-x C-n |
295 | Cancel the goal column. Henceforth, @kbd{C-n} and @kbd{C-p} try to | |
296 | preserve the horizontal position, as usual. | |
297 | @end table | |
298 | ||
6c5f6319 CY |
299 | @vindex line-move-visual |
300 | When a line of text in the buffer is longer than the width of the | |
301 | window, Emacs usually displays it on two or more @dfn{screen lines}. | |
302 | For convenience, @kbd{C-n} and @kbd{C-p} move point by screen lines, | |
303 | as do the equivalent keys @kbd{@key{down}} and @kbd{@key{up}}. You | |
304 | can force these commands to move according to @dfn{logical lines} | |
305 | (i.e., according to the text lines in the buffer) by setting the | |
306 | variable @code{line-move-visual} to @code{nil}; if a logical line | |
307 | occupies multiple screen lines, the cursor then skips over the | |
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308 | additional screen lines. For details, see @ref{Continuation Lines}. |
309 | @xref{Variables}, for how to set variables such as | |
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310 | @code{line-move-visual}. |
311 | ||
312 | Unlike @kbd{C-n} and @kbd{C-p}, most of the Emacs commands that work | |
313 | on lines work on @emph{logical} lines. For instance, @kbd{C-a} | |
314 | (@code{move-beginning-of-line}) and @kbd{C-e} | |
315 | (@code{move-end-of-line}) respectively move to the beginning and end | |
316 | of the logical line. Whenever we encounter commands that work on | |
317 | screen lines, such as @kbd{C-n} and @kbd{C-p}, we will point these | |
318 | out. | |
319 | ||
8cf51b2c | 320 | @vindex track-eol |
6c5f6319 CY |
321 | When @code{line-move-visual} is @code{nil}, you can also set the |
322 | variable @code{track-eol} to a non-@code{nil} value. Then @kbd{C-n} | |
323 | and @kbd{C-p}, when starting at the end of the logical line, move to | |
324 | the end of the next logical line. Normally, @code{track-eol} is | |
325 | @code{nil}. | |
8cf51b2c GM |
326 | |
327 | @vindex next-line-add-newlines | |
328 | @kbd{C-n} normally stops at the end of the buffer when you use it on | |
de0bde62 | 329 | the last line in the buffer. However, if you set the variable |
8cf51b2c GM |
330 | @code{next-line-add-newlines} to a non-@code{nil} value, @kbd{C-n} on |
331 | the last line of a buffer creates an additional line at the end and | |
332 | moves down into it. | |
333 | ||
334 | @node Erasing | |
335 | @section Erasing Text | |
de0bde62 CY |
336 | @cindex killing characters and lines |
337 | @cindex deleting characters and lines | |
338 | @cindex erasing characters and lines | |
8cf51b2c GM |
339 | |
340 | @table @kbd | |
341 | @item @key{DEL} | |
6c5f6319 | 342 | @itemx @key{Backspace} |
de0bde62 CY |
343 | Delete the character before point, or the region if it is active |
344 | (@code{delete-backward-char}). | |
345 | ||
6c5f6319 | 346 | @itemx @key{Delete} |
de0bde62 CY |
347 | Delete the character after point, or the region if it is active |
348 | (@code{delete-forward-char}). | |
349 | ||
350 | @item C-d | |
8cf51b2c | 351 | Delete the character after point (@code{delete-char}). |
de0bde62 | 352 | |
8cf51b2c GM |
353 | @item C-k |
354 | Kill to the end of the line (@code{kill-line}). | |
355 | @item M-d | |
356 | Kill forward to the end of the next word (@code{kill-word}). | |
357 | @item M-@key{DEL} | |
358 | Kill back to the beginning of the previous word | |
359 | (@code{backward-kill-word}). | |
360 | @end table | |
361 | ||
de0bde62 CY |
362 | The @kbd{@key{DEL}} (@code{delete-backward-char}) command removes |
363 | the character before point, moving the cursor and the characters after | |
364 | it backwards. If point was at the beginning of a line, this deletes | |
365 | the preceding newline, joining this line to the previous one. | |
6c5f6319 | 366 | |
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367 | If, however, the region is active, @kbd{@key{DEL}} instead deletes |
368 | the text in the region. @xref{Mark}, for a description of the region. | |
6c5f6319 | 369 | |
bfd779dd | 370 | On most keyboards, @key{DEL} is labeled @key{Backspace}, but we |
de0bde62 CY |
371 | refer to it as @key{DEL} in this manual. (Do not confuse @key{DEL} |
372 | with the @key{Delete} key; we will discuss @key{Delete} momentarily.) | |
373 | On some text-only terminals, Emacs may not recognize the @key{DEL} key | |
374 | properly. @xref{DEL Does Not Delete}, if you encounter this problem. | |
6c5f6319 | 375 | |
de0bde62 CY |
376 | The @key{delete} (@code{delete-forward-char}) command deletes in the |
377 | ``opposite direction'': it deletes the character after point, i.e. the | |
378 | character under the cursor. If point was at the end of a line, this | |
379 | joins the following line onto this one. Like @kbd{@key{DEL}}, it | |
380 | deletes the text in the region if the region is active (@pxref{Mark}). | |
8cf51b2c | 381 | |
de0bde62 CY |
382 | @kbd{C-d} (@code{delete-char}) deletes the character after point, |
383 | similar to @key{delete}, but regardless of whether the region is | |
384 | active. | |
8cf51b2c | 385 | |
de0bde62 CY |
386 | @xref{Deletion}, for more detailed information about the above |
387 | deletion commands. | |
388 | ||
389 | @kbd{C-k} (@code{kill-line}) erases (kills) a line at a time. If | |
390 | you type @kbd{C-k} at the beginning or middle of a line, it kills all | |
391 | the text up to the end of the line. If you type @kbd{C-k} at the end | |
392 | of a line, it joins that line with the following line. | |
393 | ||
394 | @xref{Killing}, for more information about @kbd{C-k} and related | |
395 | commands. | |
8cf51b2c GM |
396 | |
397 | @node Basic Undo | |
398 | @section Undoing Changes | |
399 | ||
8cf51b2c | 400 | @table @kbd |
6c5f6319 | 401 | @item C-/ |
8cf51b2c GM |
402 | Undo one entry of the undo records---usually, one command worth |
403 | (@code{undo}). | |
6c5f6319 | 404 | @itemx C-x u |
de0bde62 | 405 | @itemx C-_ |
8cf51b2c GM |
406 | The same. |
407 | @end table | |
408 | ||
6c5f6319 CY |
409 | Emacs records a list of changes made in the buffer text, so you can |
410 | undo recent changes. This is done using the @code{undo} command, | |
411 | which is bound to @kbd{C-/} (as well as @kbd{C-x u} and @kbd{C-_}). | |
412 | Normally, this command undoes the last change, moving point back to | |
413 | where it was before the change. The undo command applies only to | |
414 | changes in the buffer; you can't use it to undo cursor motion. | |
415 | ||
416 | Although each editing command usually makes a separate entry in the | |
417 | undo records, very simple commands may be grouped together. | |
418 | Sometimes, an entry may cover just part of a complex command. | |
8cf51b2c | 419 | |
6c5f6319 | 420 | If you repeat @kbd{C-/} (or its aliases), each repetition undoes |
8cf51b2c GM |
421 | another, earlier change, back to the limit of the undo information |
422 | available. If all recorded changes have already been undone, the undo | |
423 | command displays an error message and does nothing. | |
424 | ||
6c5f6319 | 425 | To learn more about the @code{undo} command, see @ref{Undo}. |
8cf51b2c GM |
426 | |
427 | @node Basic Files | |
428 | @section Files | |
429 | ||
430 | Text that you insert in an Emacs buffer lasts only as long as the | |
6c5f6319 | 431 | Emacs session. To keep any text permanently, you must put it in a |
de0bde62 | 432 | @dfn{file}. |
8cf51b2c GM |
433 | |
434 | Suppose there is a file named @file{test.emacs} in your home | |
435 | directory. To begin editing this file in Emacs, type | |
436 | ||
437 | @example | |
438 | C-x C-f test.emacs @key{RET} | |
439 | @end example | |
440 | ||
441 | @noindent | |
442 | Here the file name is given as an @dfn{argument} to the command @kbd{C-x | |
443 | C-f} (@code{find-file}). That command uses the @dfn{minibuffer} to | |
444 | read the argument, and you type @key{RET} to terminate the argument | |
445 | (@pxref{Minibuffer}). | |
446 | ||
447 | Emacs obeys this command by @dfn{visiting} the file: it creates a | |
6c5f6319 | 448 | buffer, copies the contents of the file into the buffer, and then |
8cf51b2c GM |
449 | displays the buffer for editing. If you alter the text, you can |
450 | @dfn{save} the new text in the file by typing @kbd{C-x C-s} | |
451 | (@code{save-buffer}). This copies the altered buffer contents back | |
452 | into the file @file{test.emacs}, making them permanent. Until you | |
453 | save, the changed text exists only inside Emacs, and the file | |
454 | @file{test.emacs} is unaltered. | |
455 | ||
456 | To create a file, just visit it with @kbd{C-x C-f} as if it already | |
457 | existed. This creates an empty buffer, in which you can insert the | |
458 | text you want to put in the file. Emacs actually creates the file the | |
459 | first time you save this buffer with @kbd{C-x C-s}. | |
460 | ||
461 | To learn more about using files in Emacs, see @ref{Files}. | |
462 | ||
463 | @node Basic Help | |
464 | @section Help | |
465 | ||
466 | @cindex getting help with keys | |
de0bde62 CY |
467 | If you forget what a key does, you can find out by typing @kbd{C-h |
468 | k} (@code{describe-key}), followed by the key of interest; for | |
469 | example, @kbd{C-h k C-n} tells you what @kbd{C-n} does. | |
470 | ||
471 | The prefix key @kbd{C-h} stands for ``help''. The key @key{F1} | |
472 | serves as an alias for @kbd{C-h}. Apart from @kbd{C-h k}, there are | |
473 | many other help commands providing different kinds of help. | |
474 | ||
475 | @xref{Help}, for details. | |
8cf51b2c GM |
476 | |
477 | @node Blank Lines | |
478 | @section Blank Lines | |
479 | ||
480 | @cindex inserting blank lines | |
481 | @cindex deleting blank lines | |
482 | Here are special commands and techniques for inserting and deleting | |
483 | blank lines. | |
484 | ||
485 | @table @kbd | |
486 | @item C-o | |
6c5f6319 | 487 | Insert a blank line after the cursor (@code{open-line}). |
8cf51b2c GM |
488 | @item C-x C-o |
489 | Delete all but one of many consecutive blank lines | |
490 | (@code{delete-blank-lines}). | |
491 | @end table | |
492 | ||
493 | @kindex C-o | |
494 | @kindex C-x C-o | |
495 | @cindex blank lines | |
496 | @findex open-line | |
497 | @findex delete-blank-lines | |
6c5f6319 CY |
498 | We have seen how @kbd{@key{RET}} (@code{newline}) starts a new line |
499 | of text. However, it may be easier to see what you are doing if you | |
500 | first make a blank line and then insert the desired text into it. | |
501 | This is easy to do using the key @kbd{C-o} (@code{open-line}), which | |
502 | inserts a newline after point but leaves point in front of the | |
503 | newline. After @kbd{C-o}, type the text for the new line. | |
8cf51b2c GM |
504 | |
505 | You can make several blank lines by typing @kbd{C-o} several times, or | |
506 | by giving it a numeric argument specifying how many blank lines to make. | |
507 | @xref{Arguments}, for how. If you have a fill prefix, the @kbd{C-o} | |
508 | command inserts the fill prefix on the new line, if typed at the | |
509 | beginning of a line. @xref{Fill Prefix}. | |
510 | ||
511 | The easy way to get rid of extra blank lines is with the command | |
6c5f6319 CY |
512 | @kbd{C-x C-o} (@code{delete-blank-lines}). If point lies within a run |
513 | of several blank lines, @kbd{C-x C-o} deletes all but one of them. If | |
514 | point is on a single blank line, @kbd{C-x C-o} deletes it. If point | |
515 | is on a nonblank line, @kbd{C-x C-o} deletes all following blank | |
516 | lines, if any exists. | |
8cf51b2c GM |
517 | |
518 | @node Continuation Lines | |
519 | @section Continuation Lines | |
520 | ||
521 | @cindex continuation line | |
522 | @cindex wrapping | |
523 | @cindex line wrapping | |
524 | @cindex fringes, and continuation lines | |
6c5f6319 CY |
525 | Sometimes, a line of text in the buffer---a @dfn{logical line}---is |
526 | too long to fit in the window, and Emacs displays it as two or more | |
527 | @dfn{screen lines}. This is called @dfn{line wrapping} or | |
528 | @dfn{continuation}, and the long logical line is called a | |
529 | @dfn{continued line}. On a graphical display, Emacs indicates line | |
530 | wrapping with small bent arrows in the left and right window fringes. | |
531 | On a text-only terminal, Emacs indicates line wrapping by displaying a | |
532 | @samp{\} character at the right margin. | |
533 | ||
534 | Most commands that act on lines act on logical lines, not screen | |
535 | lines. For instance, @kbd{C-k} kills a logical line. As described | |
536 | earlier, @kbd{C-n} (@code{next-line}) and @kbd{C-p} | |
537 | (@code{previous-line}) are special exceptions: they move point down | |
538 | and up, respectively, by one screen line (@pxref{Moving Point}). | |
8cf51b2c GM |
539 | |
540 | @cindex truncation | |
541 | @cindex line truncation, and fringes | |
6c5f6319 CY |
542 | Emacs can optionally @dfn{truncate} long logical lines instead of |
543 | continuing them. This means that every logical line occupies a single | |
544 | screen line; if it is longer than the width of the window, the rest of | |
545 | the line is not displayed. On a graphical display, a truncated line | |
546 | is indicated by a small straight arrow in the right fringe; on a | |
547 | text-only terminal, it is indicated by a @samp{$} character in the | |
548 | right margin. @xref{Line Truncation}. | |
549 | ||
550 | By default, continued lines are wrapped at the right window edge. | |
551 | Since the wrapping may occur in the middle of a word, continued lines | |
552 | can be difficult to read. The usual solution is to break your lines | |
553 | before they get too long, by inserting newlines. If you prefer, you | |
554 | can make Emacs insert a newline automatically when a line gets too | |
555 | long, by using Auto Fill mode. @xref{Filling}. | |
556 | ||
557 | @cindex word wrap | |
558 | Sometimes, you may need to edit files containing many long logical | |
559 | lines, and it may not be practical to break them all up by adding | |
560 | newlines. In that case, you can use Visual Line mode, which enables | |
561 | @dfn{word wrapping}: instead of wrapping long lines exactly at the | |
562 | right window edge, Emacs wraps them at the word boundaries (i.e., | |
563 | space or tab characters) nearest to the right window edge. Visual | |
564 | Line mode also redefines editing commands such as @code{C-a}, | |
565 | @code{C-n}, and @code{C-k} to operate on screen lines rather than | |
566 | logical lines. @xref{Visual Line Mode}. | |
8cf51b2c GM |
567 | |
568 | @node Position Info | |
569 | @section Cursor Position Information | |
570 | ||
571 | Here are commands to get information about the size and position of | |
b2b0776e | 572 | parts of the buffer, and to count words and lines. |
8cf51b2c GM |
573 | |
574 | @table @kbd | |
8cf51b2c | 575 | @item M-x what-line |
b2b0776e | 576 | Display the line number of point. |
8cf51b2c GM |
577 | @item M-x line-number-mode |
578 | @itemx M-x column-number-mode | |
579 | Toggle automatic display of the current line number or column number. | |
580 | @xref{Optional Mode Line}. | |
de0bde62 CY |
581 | |
582 | @item M-= | |
b2b0776e CY |
583 | Display the number of lines, words, and characters that are present in |
584 | the region (@code{count-words-region}). @xref{Mark}, for information | |
585 | about the region. | |
de0bde62 | 586 | |
b2b0776e CY |
587 | @item M-x count-words |
588 | Display the number of lines, words, and characters that are present in | |
589 | the buffer. If the region is active (@pxref{Mark}), display the | |
590 | numbers for the region instead. | |
de0bde62 | 591 | |
8cf51b2c GM |
592 | @item C-x = |
593 | Display the character code of character after point, character position of | |
594 | point, and column of point (@code{what-cursor-position}). | |
595 | @item M-x hl-line-mode | |
596 | Enable or disable highlighting of the current line. @xref{Cursor | |
597 | Display}. | |
598 | @item M-x size-indication-mode | |
599 | Toggle automatic display of the size of the buffer. | |
600 | @xref{Optional Mode Line}. | |
601 | @end table | |
602 | ||
8cf51b2c GM |
603 | @findex what-line |
604 | @cindex line number commands | |
605 | @cindex location of point | |
606 | @cindex cursor location | |
607 | @cindex point location | |
6c5f6319 CY |
608 | @kbd{M-x what-line} displays the current line number in the echo |
609 | area. This command is usually redundant, because the current line | |
610 | number is shown in the mode line (@pxref{Mode Line}). However, if you | |
867d4bb3 | 611 | narrow the buffer, the mode line shows the line number relative to |
6c5f6319 CY |
612 | the accessible portion (@pxref{Narrowing}). By contrast, |
613 | @code{what-line} displays both the line number relative to the | |
614 | narrowed region and the line number relative to the whole buffer. | |
8cf51b2c | 615 | |
8cf51b2c | 616 | @kindex M-= |
b2b0776e CY |
617 | @findex count-words-region |
618 | @findex count-words | |
619 | @kbd{M-=} (@code{count-words-region}) displays a message reporting | |
620 | the number of lines, words, and characters in the region. @kbd{M-x | |
621 | count-words} displays a similar message for the entire buffer, or for | |
622 | the region if the region is @dfn{active}. @xref{Mark}, for an | |
623 | explanation of the region. | |
8cf51b2c GM |
624 | |
625 | @kindex C-x = | |
626 | @findex what-cursor-position | |
6c5f6319 CY |
627 | The command @kbd{C-x =} (@code{what-cursor-position}) shows |
628 | information about the current cursor position and the buffer contents | |
629 | at that position. It displays a line in the echo area that looks like | |
630 | this: | |
8cf51b2c GM |
631 | |
632 | @smallexample | |
633 | Char: c (99, #o143, #x63) point=28062 of 36168 (78%) column=53 | |
634 | @end smallexample | |
635 | ||
6c5f6319 CY |
636 | After @samp{Char:}, this shows the character in the buffer at point. |
637 | The text inside the parenthesis shows the corresponding decimal, octal | |
638 | and hex character codes; for more information about how @kbd{C-x =} | |
639 | displays character information, see @ref{International Chars}. After | |
640 | @samp{point=} is the position of point as a character count (the first | |
641 | character in the buffer is position 1, the second character is | |
642 | position 2, and so on). The number after that is the total number of | |
643 | characters in the buffer, and the number in parenthesis expresses the | |
644 | position as a percentage of the total. After @samp{column=} is the | |
645 | horizontal position of point, in columns counting from the left edge | |
646 | of the window. | |
8cf51b2c GM |
647 | |
648 | If the buffer has been narrowed, making some of the text at the | |
649 | beginning and the end temporarily inaccessible, @kbd{C-x =} displays | |
6c5f6319 CY |
650 | additional text describing the currently accessible range. For |
651 | example, it might display this: | |
8cf51b2c GM |
652 | |
653 | @smallexample | |
654 | Char: C (67, #o103, #x43) point=252 of 889 (28%) <231-599> column=0 | |
655 | @end smallexample | |
656 | ||
657 | @noindent | |
658 | where the two extra numbers give the smallest and largest character | |
6c5f6319 CY |
659 | position that point is allowed to assume. The characters between |
660 | those two positions are the accessible ones. @xref{Narrowing}. | |
8cf51b2c GM |
661 | |
662 | @node Arguments | |
663 | @section Numeric Arguments | |
664 | @cindex numeric arguments | |
665 | @cindex prefix arguments | |
666 | @cindex arguments to commands | |
667 | ||
6c5f6319 CY |
668 | In the terminology of mathematics and computing, @dfn{argument} |
669 | means ``data provided to a function or operation.'' You can give any | |
670 | Emacs command a @dfn{numeric argument} (also called a @dfn{prefix | |
671 | argument}). Some commands interpret the argument as a repetition | |
672 | count. For example, giving @kbd{C-f} an argument of ten causes it to | |
673 | move point forward by ten characters instead of one. With these | |
674 | commands, no argument is equivalent to an argument of one, and | |
675 | negative arguments cause them to move or act in the opposite | |
676 | direction. | |
8cf51b2c GM |
677 | |
678 | @kindex M-1 | |
679 | @kindex M-@t{-} | |
680 | @findex digit-argument | |
681 | @findex negative-argument | |
fcda6454 | 682 | The easiest way to specify a numeric argument is to type a digit |
6c5f6319 CY |
683 | and/or a minus sign while holding down the @key{META} key. For |
684 | example, | |
8cf51b2c GM |
685 | |
686 | @example | |
687 | M-5 C-n | |
688 | @end example | |
689 | ||
690 | @noindent | |
6c5f6319 CY |
691 | moves down five lines. The keys @kbd{M-1}, @kbd{M-2}, and so on, as |
692 | well as @kbd{M--}, are bound to commands (@code{digit-argument} and | |
693 | @code{negative-argument}) that set up an argument for the next | |
694 | command. @kbd{Meta--} without digits normally means @minus{}1. | |
8cf51b2c | 695 | |
fcda6454 CY |
696 | If you enter more than one digit, you need not hold down the |
697 | @key{META} key for the second and subsequent digits. Thus, to move | |
698 | down fifty lines, type | |
699 | ||
700 | @example | |
701 | M-5 0 C-n | |
702 | @end example | |
703 | ||
704 | @noindent | |
705 | Note that this @emph{does not} insert five copies of @samp{0} and move | |
706 | down one line, as you might expect---the @samp{0} is treated as part | |
707 | of the prefix argument. | |
708 | ||
709 | (What if you do want to insert five copies of @samp{0}? Type @kbd{M-5 | |
710 | C-u 0}. Here, @kbd{C-u} ``terminates'' the prefix argument, so that | |
711 | the next keystroke begins the command that you want to execute. Note | |
712 | that this meaning of @kbd{C-u} applies only to this case. For the | |
713 | usual role of @kbd{C-u}, see below.) | |
714 | ||
8cf51b2c GM |
715 | @kindex C-u |
716 | @findex universal-argument | |
fcda6454 CY |
717 | Instead of typing @kbd{M-1}, @kbd{M-2}, and so on, another way to |
718 | specify a numeric argument is to type @kbd{C-u} | |
719 | (@code{universal-argument}) followed by some digits, or (for a | |
720 | negative argument) a minus sign followed by digits. A minus sign | |
721 | without digits normally means @minus{}1. | |
6c5f6319 CY |
722 | |
723 | @kbd{C-u} alone has the special meaning of ``four times'': it | |
724 | multiplies the argument for the next command by four. @kbd{C-u C-u} | |
725 | multiplies it by sixteen. Thus, @kbd{C-u C-u C-f} moves forward | |
726 | sixteen characters. Other useful combinations are @kbd{C-u C-n}, | |
727 | @kbd{C-u C-u C-n} (move down a good fraction of a screen), @kbd{C-u | |
728 | C-u C-o} (make ``a lot'' of blank lines), and @kbd{C-u C-k} (kill four | |
729 | lines). | |
730 | ||
731 | You can use a numeric argument before a self-inserting character to | |
732 | insert multiple copies of it. This is straightforward when the | |
733 | character is not a digit; for example, @kbd{C-u 6 4 a} inserts 64 | |
734 | copies of the character @samp{a}. But this does not work for | |
735 | inserting digits; @kbd{C-u 6 4 1} specifies an argument of 641. You | |
736 | can separate the argument from the digit to insert with another | |
737 | @kbd{C-u}; for example, @kbd{C-u 6 4 C-u 1} does insert 64 copies of | |
738 | the character @samp{1}. | |
8cf51b2c GM |
739 | |
740 | Some commands care whether there is an argument, but ignore its | |
f0a35bd4 | 741 | value. For example, the command @kbd{M-q} (@code{fill-paragraph}) |
8cf51b2c | 742 | fills text; with an argument, it justifies the text as well. |
6c5f6319 CY |
743 | (@xref{Filling}, for more information on @kbd{M-q}.) For these |
744 | commands, it is enough to the argument with a single @kbd{C-u}. | |
745 | ||
746 | Some commands use the value of the argument as a repeat count, but | |
747 | do something special when there is no argument. For example, the | |
748 | command @kbd{C-k} (@code{kill-line}) with argument @var{n} kills | |
749 | @var{n} lines, including their terminating newlines. But @kbd{C-k} | |
750 | with no argument is special: it kills the text up to the next newline, | |
751 | or, if point is right at the end of the line, it kills the newline | |
752 | itself. Thus, two @kbd{C-k} commands with no arguments can kill a | |
753 | nonblank line, just like @kbd{C-k} with an argument of one. | |
754 | (@xref{Killing}, for more information on @kbd{C-k}.) | |
8cf51b2c GM |
755 | |
756 | A few commands treat a plain @kbd{C-u} differently from an ordinary | |
757 | argument. A few others may treat an argument of just a minus sign | |
758 | differently from an argument of @minus{}1. These unusual cases are | |
759 | described when they come up; they exist to make an individual command | |
760 | more convenient, and they are documented in that command's | |
761 | documentation string. | |
762 | ||
8cf51b2c GM |
763 | We use the term ``prefix argument'' as well as ``numeric argument,'' |
764 | to emphasize that you type these argument before the command, and to | |
765 | distinguish them from minibuffer arguments that come after the | |
766 | command. | |
767 | ||
768 | @node Repeating | |
769 | @section Repeating a Command | |
770 | @cindex repeating a command | |
771 | ||
772 | Many simple commands, such as those invoked with a single key or | |
773 | with @kbd{M-x @var{command-name} @key{RET}}, can be repeated by | |
774 | invoking them with a numeric argument that serves as a repeat count | |
775 | (@pxref{Arguments}). However, if the command you want to repeat | |
776 | prompts for input, or uses a numeric argument in another way, that | |
777 | method won't work. | |
778 | ||
779 | @kindex C-x z | |
780 | @findex repeat | |
781 | The command @kbd{C-x z} (@code{repeat}) provides another way to repeat | |
782 | an Emacs command many times. This command repeats the previous Emacs | |
783 | command, whatever that was. Repeating a command uses the same arguments | |
784 | that were used before; it does not read new arguments each time. | |
785 | ||
786 | To repeat the command more than once, type additional @kbd{z}'s: each | |
787 | @kbd{z} repeats the command one more time. Repetition ends when you | |
788 | type a character other than @kbd{z}, or press a mouse button. | |
789 | ||
790 | For example, suppose you type @kbd{C-u 2 0 C-d} to delete 20 | |
791 | characters. You can repeat that command (including its argument) three | |
792 | additional times, to delete a total of 80 characters, by typing @kbd{C-x | |
793 | z z z}. The first @kbd{C-x z} repeats the command once, and each | |
794 | subsequent @kbd{z} repeats it once again. |