]> code.delx.au - gnu-emacs/blob - man/killing.texi
(Commands of GUD): Add gud-jump.
[gnu-emacs] / man / killing.texi
1 @c This is part of the Emacs manual.
2 @c Copyright (C) 1985,86,87,93,94,95,97,00,2001 Free Software Foundation, Inc.
3 @c See file emacs.texi for copying conditions.
4 @iftex
5 @chapter Killing and Moving Text
6
7 @dfn{Killing} means erasing text and copying it into the @dfn{kill
8 ring}, from which it can be retrieved by @dfn{yanking} it. Some systems
9 use the terms ``cutting'' and ``pasting'' for these operations.
10
11 The most common way of moving or copying text within Emacs is to kill it
12 and later yank it elsewhere in one or more places. This is very safe
13 because Emacs remembers several recent kills, not just the last one. It
14 is versatile, because the many commands for killing syntactic units can
15 also be used for moving those units. But there are other ways of
16 copying text for special purposes.
17
18 Emacs has only one kill ring for all buffers, so you can kill text in
19 one buffer and yank it in another buffer.
20
21 @end iftex
22
23 @node Killing, Yanking, Mark, Top
24 @section Deletion and Killing
25
26 @cindex killing text
27 @cindex cutting text
28 @cindex deletion
29 Most commands which erase text from the buffer save it in the kill
30 ring so that you can move or copy it to other parts of the buffer.
31 These commands are known as @dfn{kill} commands. The rest of the
32 commands that erase text do not save it in the kill ring; they are known
33 as @dfn{delete} commands. (This distinction is made only for erasure of
34 text in the buffer.) If you do a kill or delete command by mistake, you
35 can use the @kbd{C-x u} (@code{undo}) command to undo it
36 (@pxref{Undo}).
37
38 @vindex kill-read-only-ok
39 @cindex read-only text, killing
40 You cannot kill read-only text, since such text does not allow any
41 kind of modification. But some users like to use the kill commands to
42 copy read-only text into the kill ring, without actually changing it.
43 If you set the variable @code{kill-read-only-ok} to a non-@code{nil}
44 value, the kill commands work specially in a read-only buffer: they
45 move over text, and copy it to the kill ring, without actually
46 deleting it from the buffer. When this happens, a message in the echo
47 area tells you what is happening.
48
49 The delete commands include @kbd{C-d} (@code{delete-char}) and
50 @key{DEL} (@code{delete-backward-char}), which delete only one
51 character at a time, and those commands that delete only spaces or
52 newlines. Commands that can destroy significant amounts of nontrivial
53 data generally do a kill operation instead. The commands' names and
54 individual descriptions use the words @samp{kill} and @samp{delete} to
55 say which kind of operation they perform.
56
57 @cindex Delete Selection mode
58 @cindex mode, Delete Selection
59 @findex delete-selection-mode
60 Many window systems follow the convention that insertion while text
61 is selected deletes the selected text. You can make Emacs behave this
62 way by enabling Delete Selection mode, with @kbd{M-x
63 delete-selection-mode}, or using Custom. Another effect of this mode
64 is that @key{DEL}, @kbd{C-d} and some other keys, when a selection
65 exists, will kill the whole selection. It also enables Transient Mark
66 mode (@pxref{Transient Mark}).
67
68 @menu
69 * Deletion:: Commands for deleting small amounts of text and
70 blank areas.
71 * Killing by Lines:: How to kill entire lines of text at one time.
72 * Other Kill Commands:: Commands to kill large regions of text and
73 syntactic units such as words and sentences.
74 @end menu
75
76 @need 1500
77 @node Deletion
78 @subsection Deletion
79 @findex delete-backward-char
80 @findex delete-char
81
82 Deletion means erasing text and not saving it in the kill ring. For
83 the most part, the Emacs commands that delete text are those that
84 erase just one character or only whitespace.
85
86 @table @kbd
87 @item C-d
88 @itemx @key{Delete}
89 Delete next character (@code{delete-char}). If your keyboard has a
90 @key{Delete} function key (usually located in the edit keypad), Emacs
91 binds it to @code{delete-char} as well.
92 @item @key{DEL}
93 @itemx @key{BS}
94 Delete previous character (@code{delete-backward-char}). Some keyboards
95 refer to this key as a ``backspace key'' and label it with a left arrow.
96 @item M-\
97 Delete spaces and tabs around point (@code{delete-horizontal-space}).
98 @item M-@key{SPC}
99 Delete spaces and tabs around point, leaving one space
100 (@code{just-one-space}).
101 @item C-x C-o
102 Delete blank lines around the current line (@code{delete-blank-lines}).
103 @item M-^
104 Join two lines by deleting the intervening newline, along with any
105 indentation following it (@code{delete-indentation}).
106 @end table
107
108 @kindex DEL
109 @kindex C-d
110 The most basic delete commands are @kbd{C-d} (@code{delete-char}) and
111 @key{DEL} (@code{delete-backward-char}). @kbd{C-d} deletes the
112 character after point, the one the cursor is ``on top of.'' This
113 doesn't move point. @key{DEL} deletes the character before the cursor,
114 and moves point back. You can delete newlines like any other characters
115 in the buffer; deleting a newline joins two lines. Actually, @kbd{C-d}
116 and @key{DEL} aren't always delete commands; when given arguments, they
117 kill instead, since they can erase more than one character this way.
118
119 @kindex BACKSPACE
120 @kindex BS
121 @kindex DELETE
122 Every keyboard has a large key, labeled @key{DEL}, @key{BACKSPACE},
123 @key{BS} or @key{DELETE}, which is a short distance above the
124 @key{RET} or @key{ENTER} key and is normally used for erasing what you
125 have typed. Regardless of the actual name on the key, in Emacs it is
126 equivalent to @key{DEL}---or it should be.
127
128 Many keyboards (including standard PC keyboards) have a
129 @key{BACKSPACE} key a short ways above @key{RET} or @key{ENTER}, and a
130 @key{DELETE} key elsewhere. In that case, the @key{BACKSPACE} key is
131 @key{DEL}, and the @key{DELETE} key is equivalent to @kbd{C-d}---or it
132 should be.
133
134 Why do we say ``or it should be''? When Emacs starts up using a
135 window system, it determines automatically which key or keys should be
136 equivalent to @key{DEL}. As a result, @key{BACKSPACE} and/or @key{DELETE}
137 keys normally do the right things. But in some unusual cases Emacs
138 gets the wrong information from the system. If these keys don't do
139 what they ought to do, you need to tell Emacs which key to use for
140 @key{DEL}. @xref{DEL Does Not Delete}, for how to do this.
141
142 @findex normal-erase-is-backspace-mode
143 On most text-only terminals, Emacs cannot tell which keys the
144 keyboard really has, so it follows a uniform plan which may or may not
145 fit your keyboard. The uniform plan is that the ASCII @key{DEL}
146 character deletes, and the ASCII @key{BS} (backspace) character asks
147 for help (it is the same as @kbd{C-h}). If this is not right for your
148 keyboard, such as if you find that the key which ought to delete backwards
149 enters Help instead, see @ref{DEL Does Not Delete}.
150
151 @kindex M-\
152 @findex delete-horizontal-space
153 @kindex M-SPC
154 @findex just-one-space
155 The other delete commands are those which delete only whitespace
156 characters: spaces, tabs and newlines. @kbd{M-\}
157 (@code{delete-horizontal-space}) deletes all the spaces and tab
158 characters before and after point. @kbd{M-@key{SPC}}
159 (@code{just-one-space}) does likewise but leaves a single space after
160 point, regardless of the number of spaces that existed previously (even
161 if there were none before).
162
163 @kbd{C-x C-o} (@code{delete-blank-lines}) deletes all blank lines
164 after the current line. If the current line is blank, it deletes all
165 blank lines preceding the current line as well (leaving one blank line,
166 the current line).
167
168 @kbd{M-^} (@code{delete-indentation}) joins the current line and the
169 previous line, by deleting a newline and all surrounding spaces, usually
170 leaving a single space. @xref{Indentation,M-^}.
171
172 @node Killing by Lines
173 @subsection Killing by Lines
174
175 @table @kbd
176 @item C-k
177 Kill rest of line or one or more lines (@code{kill-line}).
178 @end table
179
180 @kindex C-k
181 @findex kill-line
182 The simplest kill command is @kbd{C-k}. If given at the beginning of
183 a line, it kills all the text on the line, leaving it blank. When used
184 on a blank line, it kills the whole line including its newline. To kill
185 an entire non-blank line, go to the beginning and type @kbd{C-k} twice.
186
187 More generally, @kbd{C-k} kills from point up to the end of the line,
188 unless it is at the end of a line. In that case it kills the newline
189 following point, thus merging the next line into the current one.
190 Spaces and tabs that you can't see at the end of the line are ignored
191 when deciding which case applies, so if point appears to be at the end
192 of the line, you can be sure @kbd{C-k} will kill the newline.
193
194 When @kbd{C-k} is given a positive argument, it kills that many lines
195 and the newlines that follow them (however, text on the current line
196 before point is not killed). With a negative argument @minus{}@var{n}, it
197 kills @var{n} lines preceding the current line (together with the text
198 on the current line before point). Thus, @kbd{C-u - 2 C-k} at the front
199 of a line kills the two previous lines.
200
201 @kbd{C-k} with an argument of zero kills the text before point on the
202 current line.
203
204 @vindex kill-whole-line
205 If the variable @code{kill-whole-line} is non-@code{nil}, @kbd{C-k} at
206 the very beginning of a line kills the entire line including the
207 following newline. This variable is normally @code{nil}.
208
209 @node Other Kill Commands
210 @subsection Other Kill Commands
211 @findex kill-region
212 @kindex C-w
213
214 @table @kbd
215 @item C-w
216 Kill region (from point to the mark) (@code{kill-region}).
217 @item M-d
218 Kill word (@code{kill-word}). @xref{Words}.
219 @item M-@key{DEL}
220 Kill word backwards (@code{backward-kill-word}).
221 @item C-x @key{DEL}
222 Kill back to beginning of sentence (@code{backward-kill-sentence}).
223 @xref{Sentences}.
224 @item M-k
225 Kill to end of sentence (@code{kill-sentence}).
226 @item C-M-k
227 Kill the following balanced expression (@code{kill-sexp}). @xref{Expressions}.
228 @item M-z @var{char}
229 Kill through the next occurrence of @var{char} (@code{zap-to-char}).
230 @end table
231
232 A kill command which is very general is @kbd{C-w}
233 (@code{kill-region}), which kills everything between point and the
234 mark. With this command, you can kill any contiguous sequence of
235 characters, if you first set the region around them.
236
237 @kindex M-z
238 @findex zap-to-char
239 A convenient way of killing is combined with searching: @kbd{M-z}
240 (@code{zap-to-char}) reads a character and kills from point up to (and
241 including) the next occurrence of that character in the buffer. A
242 numeric argument acts as a repeat count. A negative argument means to
243 search backward and kill text before point.
244
245 Other syntactic units can be killed: words, with @kbd{M-@key{DEL}}
246 and @kbd{M-d} (@pxref{Words}); balanced expressions, with @kbd{C-M-k}
247 (@pxref{Expressions}); and sentences, with @kbd{C-x @key{DEL}} and
248 @kbd{M-k} (@pxref{Sentences}).@refill
249
250 You can use kill commands in read-only buffers. They don't actually
251 change the buffer, and they beep to warn you of that, but they do copy
252 the text you tried to kill into the kill ring, so you can yank it into
253 other buffers. Most of the kill commands move point across the text
254 they copy in this way, so that successive kill commands build up a
255 single kill ring entry as usual.
256
257 @node Yanking, Accumulating Text, Killing, Top
258 @section Yanking
259 @cindex moving text
260 @cindex copying text
261 @cindex kill ring
262 @cindex yanking
263 @cindex pasting
264
265 @dfn{Yanking} means reinserting text previously killed. This is what
266 some systems call ``pasting.'' The usual way to move or copy text is to
267 kill it and then yank it elsewhere one or more times.
268
269 @table @kbd
270 @item C-y
271 Yank last killed text (@code{yank}).
272 @item M-y
273 Replace text just yanked with an earlier batch of killed text
274 (@code{yank-pop}).
275 @item M-w
276 Save region as last killed text without actually killing it
277 (@code{kill-ring-save}).
278 @item C-M-w
279 Append next kill to last batch of killed text (@code{append-next-kill}).
280 @end table
281
282 @menu
283 * Kill Ring:: Where killed text is stored. Basic yanking.
284 * Appending Kills:: Several kills in a row all yank together.
285 * Earlier Kills:: Yanking something killed some time ago.
286 @end menu
287
288 @node Kill Ring
289 @subsection The Kill Ring
290
291 All killed text is recorded in the @dfn{kill ring}, a list of blocks of
292 text that have been killed. There is only one kill ring, shared by all
293 buffers, so you can kill text in one buffer and yank it in another buffer.
294 This is the usual way to move text from one file to another.
295 (@xref{Accumulating Text}, for some other ways.)
296
297 @kindex C-y
298 @findex yank
299 The command @kbd{C-y} (@code{yank}) reinserts the text of the most recent
300 kill. It leaves the cursor at the end of the text. It sets the mark at
301 the beginning of the text. @xref{Mark}.
302
303 @kbd{C-u C-y} leaves the cursor in front of the text, and sets the
304 mark after it. This happens only if the argument is specified with just
305 a @kbd{C-u}, precisely. Any other sort of argument, including @kbd{C-u}
306 and digits, specifies an earlier kill to yank (@pxref{Earlier Kills}).
307
308 @kindex M-w
309 @findex kill-ring-save
310 To copy a block of text, you can use @kbd{M-w}
311 (@code{kill-ring-save}), which copies the region into the kill ring
312 without removing it from the buffer. This is approximately equivalent
313 to @kbd{C-w} followed by @kbd{C-x u}, except that @kbd{M-w} does not
314 alter the undo history and does not temporarily change the screen.
315
316 @node Appending Kills
317 @subsection Appending Kills
318
319 @cindex appending kills in the ring
320 @cindex television
321 Normally, each kill command pushes a new entry onto the kill ring.
322 However, two or more kill commands in a row combine their text into a
323 single entry, so that a single @kbd{C-y} yanks all the text as a unit,
324 just as it was before it was killed.
325
326 Thus, if you want to yank text as a unit, you need not kill all of it
327 with one command; you can keep killing line after line, or word after
328 word, until you have killed it all, and you can still get it all back at
329 once.
330
331 Commands that kill forward from point add onto the end of the previous
332 killed text. Commands that kill backward from point add text onto the
333 beginning. This way, any sequence of mixed forward and backward kill
334 commands puts all the killed text into one entry without rearrangement.
335 Numeric arguments do not break the sequence of appending kills. For
336 example, suppose the buffer contains this text:
337
338 @example
339 This is a line @point{}of sample text.
340 @end example
341
342 @noindent
343 with point shown by @point{}. If you type @kbd{M-d M-@key{DEL} M-d
344 M-@key{DEL}}, killing alternately forward and backward, you end up with
345 @samp{a line of sample} as one entry in the kill ring, and @samp{This
346 is@ @ text.} in the buffer. (Note the double space between @samp{is}
347 and @samp{text}, which you can clean up with @kbd{M-@key{SPC}} or
348 @kbd{M-q}.)
349
350 Another way to kill the same text is to move back two words with
351 @kbd{M-b M-b}, then kill all four words forward with @kbd{C-u M-d}.
352 This produces exactly the same results in the buffer and in the kill
353 ring. @kbd{M-f M-f C-u M-@key{DEL}} kills the same text, all going
354 backward; once again, the result is the same. The text in the kill ring
355 entry always has the same order that it had in the buffer before you
356 killed it.
357
358 @kindex C-M-w
359 @findex append-next-kill
360 If a kill command is separated from the last kill command by other
361 commands (not just numeric arguments), it starts a new entry on the kill
362 ring. But you can force it to append by first typing the command
363 @kbd{C-M-w} (@code{append-next-kill}) right before it. The @kbd{C-M-w}
364 tells the following command, if it is a kill command, to append the text
365 it kills to the last killed text, instead of starting a new entry. With
366 @kbd{C-M-w}, you can kill several separated pieces of text and
367 accumulate them to be yanked back in one place.@refill
368
369 A kill command following @kbd{M-w} does not append to the text that
370 @kbd{M-w} copied into the kill ring.
371
372 @node Earlier Kills
373 @subsection Yanking Earlier Kills
374
375 @cindex yanking previous kills
376 @kindex M-y
377 @findex yank-pop
378 To recover killed text that is no longer the most recent kill, use the
379 @kbd{M-y} command (@code{yank-pop}). It takes the text previously
380 yanked and replaces it with the text from an earlier kill. So, to
381 recover the text of the next-to-the-last kill, first use @kbd{C-y} to
382 yank the last kill, and then use @kbd{M-y} to replace it with the
383 previous kill. @kbd{M-y} is allowed only after a @kbd{C-y} or another
384 @kbd{M-y}.
385
386 You can understand @kbd{M-y} in terms of a ``last yank'' pointer which
387 points at an entry in the kill ring. Each time you kill, the ``last
388 yank'' pointer moves to the newly made entry at the front of the ring.
389 @kbd{C-y} yanks the entry which the ``last yank'' pointer points to.
390 @kbd{M-y} moves the ``last yank'' pointer to a different entry, and the
391 text in the buffer changes to match. Enough @kbd{M-y} commands can move
392 the pointer to any entry in the ring, so you can get any entry into the
393 buffer. Eventually the pointer reaches the end of the ring; the next
394 @kbd{M-y} loops back around to the first entry again.
395
396 @kbd{M-y} moves the ``last yank'' pointer around the ring, but it does
397 not change the order of the entries in the ring, which always runs from
398 the most recent kill at the front to the oldest one still remembered.
399
400 @kbd{M-y} can take a numeric argument, which tells it how many entries
401 to advance the ``last yank'' pointer by. A negative argument moves the
402 pointer toward the front of the ring; from the front of the ring, it
403 moves ``around'' to the last entry and continues forward from there.
404
405 Once the text you are looking for is brought into the buffer, you can
406 stop doing @kbd{M-y} commands and it will stay there. It's just a copy
407 of the kill ring entry, so editing it in the buffer does not change
408 what's in the ring. As long as no new killing is done, the ``last
409 yank'' pointer remains at the same place in the kill ring, so repeating
410 @kbd{C-y} will yank another copy of the same previous kill.
411
412 If you know how many @kbd{M-y} commands it would take to find the
413 text you want, you can yank that text in one step using @kbd{C-y} with
414 a numeric argument. @kbd{C-y} with an argument restores the text from
415 the specified kill ring entry, counting back from the most recent as
416 1. Thus, @kbd{C-u 2 C-y} gets the next-to-the-last block of killed
417 text---it is equivalent to @kbd{C-y M-y}. @kbd{C-y} with a numeric
418 argument starts counting from the ``last yank'' pointer, and sets the
419 ``last yank'' pointer to the entry that it yanks.
420
421 @vindex kill-ring-max
422 The length of the kill ring is controlled by the variable
423 @code{kill-ring-max}; no more than that many blocks of killed text are
424 saved.
425
426 @vindex kill-ring
427 The actual contents of the kill ring are stored in a variable named
428 @code{kill-ring}; you can view the entire contents of the kill ring with
429 the command @kbd{C-h v kill-ring}.
430
431 @node Accumulating Text, Rectangles, Yanking, Top
432 @section Accumulating Text
433 @findex append-to-buffer
434 @findex prepend-to-buffer
435 @findex copy-to-buffer
436 @findex append-to-file
437
438 @cindex accumulating scattered text
439 Usually we copy or move text by killing it and yanking it, but there
440 are other methods convenient for copying one block of text in many
441 places, or for copying many scattered blocks of text into one place. To
442 copy one block to many places, store it in a register
443 (@pxref{Registers}). Here we describe the commands to accumulate
444 scattered pieces of text into a buffer or into a file.
445
446 @table @kbd
447 @item M-x append-to-buffer
448 Append region to the contents of a specified buffer.
449 @item M-x prepend-to-buffer
450 Prepend region to the contents of a specified buffer.
451 @item M-x copy-to-buffer
452 Copy region into a specified buffer, deleting that buffer's old contents.
453 @item M-x insert-buffer
454 Insert the contents of a specified buffer into current buffer at point.
455 @item M-x append-to-file
456 Append region to the contents of a specified file, at the end.
457 @end table
458
459 To accumulate text into a buffer, use @kbd{M-x append-to-buffer}.
460 This reads a buffer name, then inserts a copy of the region into the
461 buffer specified. If you specify a nonexistent buffer,
462 @code{append-to-buffer} creates the buffer. The text is inserted
463 wherever point is in that buffer. If you have been using the buffer for
464 editing, the copied text goes into the middle of the text of the buffer,
465 starting from wherever point happens to be at that moment.
466
467 Point in that buffer is left at the end of the copied text, so
468 successive uses of @code{append-to-buffer} accumulate the text in the
469 specified buffer in the same order as they were copied. Strictly
470 speaking, @code{append-to-buffer} does not always append to the text
471 already in the buffer---it appends only if point in that buffer is at the end.
472 However, if @code{append-to-buffer} is the only command you use to alter
473 a buffer, then point is always at the end.
474
475 @kbd{M-x prepend-to-buffer} is just like @code{append-to-buffer}
476 except that point in the other buffer is left before the copied text, so
477 successive prependings add text in reverse order. @kbd{M-x
478 copy-to-buffer} is similar, except that any existing text in the other
479 buffer is deleted, so the buffer is left containing just the text newly
480 copied into it.
481
482 To retrieve the accumulated text from another buffer, use the
483 command @kbd{M-x insert-buffer}; this too takes @var{buffername} as an
484 argument. It inserts a copy of the whole text in buffer
485 @var{buffername} into the current buffer at point, and sets the mark
486 after the inserted text. Alternatively, you can select the other
487 buffer for editing, then copy text from it by killing.
488 @xref{Buffers}, for background information on buffers.
489
490 Instead of accumulating text within Emacs, in a buffer, you can append
491 text directly into a file with @kbd{M-x append-to-file}, which takes
492 @var{filename} as an argument. It adds the text of the region to the end
493 of the specified file. The file is changed immediately on disk.
494
495 You should use @code{append-to-file} only with files that are
496 @emph{not} being visited in Emacs. Using it on a file that you are
497 editing in Emacs would change the file behind Emacs's back, which
498 can lead to losing some of your editing.
499
500 @node Rectangles, Registers, Accumulating Text, Top
501 @section Rectangles
502 @cindex rectangle
503 @cindex columns (and rectangles)
504 @cindex killing rectangular areas of text
505
506 The rectangle commands operate on rectangular areas of the text: all
507 the characters between a certain pair of columns, in a certain range of
508 lines. Commands are provided to kill rectangles, yank killed rectangles,
509 clear them out, fill them with blanks or text, or delete them. Rectangle
510 commands are useful with text in multicolumn formats, and for changing
511 text into or out of such formats.
512
513 When you must specify a rectangle for a command to work on, you do it
514 by putting the mark at one corner and point at the opposite corner. The
515 rectangle thus specified is called the @dfn{region-rectangle} because
516 you control it in much the same way as the region is controlled. But
517 remember that a given combination of point and mark values can be
518 interpreted either as a region or as a rectangle, depending on the
519 command that uses them.
520
521 If point and the mark are in the same column, the rectangle they
522 delimit is empty. If they are in the same line, the rectangle is one
523 line high. This asymmetry between lines and columns comes about
524 because point (and likewise the mark) is between two columns, but within
525 a line.
526
527 @table @kbd
528 @item C-x r k
529 Kill the text of the region-rectangle, saving its contents as the
530 ``last killed rectangle'' (@code{kill-rectangle}).
531 @item C-x r d
532 Delete the text of the region-rectangle (@code{delete-rectangle}).
533 @item C-x r y
534 Yank the last killed rectangle with its upper left corner at point
535 (@code{yank-rectangle}).
536 @item C-x r o
537 Insert blank space to fill the space of the region-rectangle
538 (@code{open-rectangle}). This pushes the previous contents of the
539 region-rectangle rightward.
540 @item M-x clear-rectangle
541 Clear the region-rectangle by replacing its contents with spaces.
542 @item M-x delete-whitespace-rectangle
543 Delete whitespace in each of the lines on the specified rectangle,
544 starting from the left edge column of the rectangle.
545 @item C-x r t @var{string} @key{RET}
546 Replace rectangle contents with @var{string} on each line.
547 (@code{string-rectangle}).
548 @item M-x string-insert-rectangle @key{RET} @var{string} @key{RET}
549 Insert @var{string} on each line of the rectangle.
550 @end table
551
552 The rectangle operations fall into two classes: commands for
553 deleting and inserting rectangles, and commands for blank rectangles.
554
555 @kindex C-x r k
556 @kindex C-x r d
557 @findex kill-rectangle
558 @findex delete-rectangle
559 There are two ways to get rid of the text in a rectangle: you can
560 discard the text (delete it) or save it as the ``last killed''
561 rectangle. The commands for these two ways are @kbd{C-x r d}
562 (@code{delete-rectangle}) and @kbd{C-x r k} (@code{kill-rectangle}). In
563 either case, the portion of each line that falls inside the rectangle's
564 boundaries is deleted, causing any following text on the line to
565 move left into the gap.
566
567 Note that ``killing'' a rectangle is not killing in the usual sense; the
568 rectangle is not stored in the kill ring, but in a special place that
569 can only record the most recent rectangle killed. This is because yanking
570 a rectangle is so different from yanking linear text that different yank
571 commands have to be used and yank-popping is hard to make sense of.
572
573 @kindex C-x r y
574 @findex yank-rectangle
575 To yank the last killed rectangle, type @kbd{C-x r y}
576 (@code{yank-rectangle}). Yanking a rectangle is the opposite of killing
577 one. Point specifies where to put the rectangle's upper left corner.
578 The rectangle's first line is inserted there, the rectangle's second
579 line is inserted at the same horizontal position, but one line
580 vertically down, and so on. The number of lines affected is determined
581 by the height of the saved rectangle.
582
583 You can convert single-column lists into double-column lists using
584 rectangle killing and yanking; kill the second half of the list as a
585 rectangle and then yank it beside the first line of the list.
586 @xref{Two-Column}, for another way to edit multi-column text.
587
588 You can also copy rectangles into and out of registers with @kbd{C-x r
589 r @var{r}} and @kbd{C-x r i @var{r}}. @xref{RegRect,,Rectangle
590 Registers}.
591
592 @kindex C-x r o
593 @findex open-rectangle
594 @findex clear-rectangle
595 There are two commands you can use for making blank rectangles:
596 @kbd{M-x clear-rectangle} which blanks out existing text, and @kbd{C-x r
597 o} (@code{open-rectangle}) which inserts a blank rectangle. Clearing a
598 rectangle is equivalent to deleting it and then inserting a blank
599 rectangle of the same size.
600
601 @findex delete-whitespace-rectangle
602 The command @kbd{M-x delete-whitespace-rectangle} deletes horizontal
603 whitespace starting from a particular column. This applies to each of
604 the lines in the rectangle, and the column is specified by the left
605 edge of the rectangle. The right edge of the rectangle does not make
606 any difference to this command.
607
608 @kindex C-x r t
609 @findex string-rectangle
610 The command @kbd{C-x r t} (@code{string-rectangle}) replaces the
611 contents of a region-rectangle with a string on each line. The
612 string's width need not be the same as the width of the rectangle. If
613 the string's width is less, the text after the rectangle shifts left;
614 if the string is wider than the rectangle, the text after the
615 rectangle shifts right.
616
617 @findex string-insert-rectangle
618 The command @kbd{M-x string-insert-rectangle} is similar to
619 @code{string-rectangle}, but inserts the string on each line,
620 shifting the original text to the right.