428
+ − 1
+ − 2 @iftex
+ − 3 @chapter Killing and Moving Text
+ − 4
+ − 5 @dfn{Killing} means erasing text and copying it into the @dfn{kill ring},
+ − 6 from which it can be retrieved by @dfn{yanking} it. Some other systems
+ − 7 that have recently become popular use the terms ``cutting'' and ``pasting''
+ − 8 for these operations.
+ − 9
+ − 10 The most common way of moving or copying text with Emacs is to kill it
+ − 11 and later yank it in one or more places. This is safe because all the
+ − 12 text killed recently is stored in the kill ring, and it is versatile,
+ − 13 because you can use the same commands for killing syntactic units and
+ − 14 for moving those units. There are other ways of copying text for
+ − 15 special purposes.
+ − 16
+ − 17 Emacs has only one kill ring, so you can kill text in one buffer and yank
+ − 18 it in another buffer. If you are using XEmacs under X, you can
+ − 19 also use the X selection mechanism to copy text from one buffer to
+ − 20 another, or between applications. @xref{Using X Selections}.
+ − 21
+ − 22 @end iftex
+ − 23
+ − 24 @node Killing, Yanking, Additional Mouse Operations, Top
+ − 25 @section Deletion and Killing
+ − 26 @findex delete-char
+ − 27 @findex delete-backward-char
+ − 28
+ − 29 @cindex killing
+ − 30 @cindex cutting
+ − 31 @cindex deletion
+ − 32 @kindex C-d
+ − 33 @kindex DEL
+ − 34 Most commands that erase text from the buffer save it. You can get
+ − 35 the text back if you change your mind, or you can move or copy it to
+ − 36 other parts of the buffer. Commands which erase text and save it in the
+ − 37 kill ring are known as @dfn{kill} commands. Some other commands erase
+ − 38 text but do not save it; they are known as @dfn{delete} commands. (This
+ − 39 distinction is made only for erasing text in the buffer.)
+ − 40
+ − 41 The commands' names and individual descriptions use the words
+ − 42 @samp{kill} and @samp{delete} to indicate what they do. If you perform
+ − 43 a kill or delete command by mistake, use the @kbd{C-x u} (@code{undo})
+ − 44 command to undo it (@pxref{Undo}). The delete commands include @kbd{C-d}
+ − 45 (@code{delete-char}) and @key{DEL} (@code{delete-backward-char}), which
+ − 46 delete only one character at a time, and those commands that delete only
+ − 47 spaces or newlines. Commands that can destroy significant amounts of
+ − 48 nontrivial data usually kill.@refill
+ − 49
+ − 50 @subsection Deletion
+ − 51
+ − 52 @table @kbd
+ − 53 @item C-d
+ − 54 Delete next character (@code{delete-char}).
+ − 55 @item @key{DEL}
+ − 56 Delete previous character (@code{delete-backward-char}).
+ − 57 @item M-\
+ − 58 Delete spaces and tabs around point (@code{delete-horizontal-space}).
+ − 59 @item M-@key{SPC}
+ − 60 Delete spaces and tabs around point, leaving one space
+ − 61 (@code{just-one-space}).
+ − 62 @item C-x C-o
+ − 63 Delete blank lines around the current line (@code{delete-blank-lines}).
+ − 64 @item M-^
+ − 65 Join two lines by deleting the intervening newline, and any indentation
+ − 66 following it (@code{delete-indentation}).
+ − 67 @end table
+ − 68
+ − 69 The most basic delete commands are @kbd{C-d} (@code{delete-char}) and
+ − 70 @key{DEL} (@code{delete-backward-char}). @kbd{C-d} deletes the
+ − 71 character after point, the one the cursor is ``on top of''. Point
+ − 72 doesn't move. @key{DEL} deletes the character before the cursor, and
+ − 73 moves point back. You can delete newlines like any other characters in
+ − 74 the buffer; deleting a newline joins two lines. Actually, @kbd{C-d} and
+ − 75 @key{DEL} aren't always delete commands; if you give them an argument,
+ − 76 they kill instead, since they can erase more than one character this
+ − 77 way.
+ − 78
+ − 79 @kindex M-\
+ − 80 @findex delete-horizontal-space
+ − 81 @kindex M-SPC
+ − 82 @findex just-one-space
+ − 83 @kindex C-x C-o
+ − 84 @findex delete-blank-lines
+ − 85 @kindex M-^
+ − 86 @findex delete-indentation
+ − 87 The other delete commands delete only formatting characters: spaces,
+ − 88 tabs and newlines. @kbd{M-\} (@code{delete-horizontal-space}) deletes
+ − 89 all spaces and tab characters before and after point.
+ − 90 @kbd{M-@key{SPC}} (@code{just-one-space}) does the same but leaves a
+ − 91 single space after point, regardless of the number of spaces that
+ − 92 existed previously (even zero).
+ − 93
+ − 94 @kbd{C-x C-o} (@code{delete-blank-lines}) deletes all blank lines after
+ − 95 the current line. If the current line is blank, it deletes all blank lines
+ − 96 preceding the current line as well as leaving one blank line, the current
+ − 97 line. @kbd{M-^} (@code{delete-indentation}) joins the current line and
+ − 98 the previous line, or, if given an argument, joins the current line and
+ − 99 the next line by deleting a newline and all surrounding spaces, possibly
+ − 100 leaving a single space. @xref{Indentation,M-^}.
+ − 101
+ − 102 @subsection Killing by Lines
+ − 103
+ − 104 @table @kbd
+ − 105 @item C-k
+ − 106 Kill rest of line or one or more lines (@code{kill-line}).
+ − 107 @end table
+ − 108
+ − 109 @kindex C-k
+ − 110 @findex kill-line
+ − 111 The simplest kill command is @kbd{C-k}. If given at the beginning of
+ − 112 a line, it kills all the text on the line, leaving the line blank. If
+ − 113 given on a blank line, the blank line disappears. As a consequence, a
+ − 114 line disappears completely if you go to the front of a non-blank line
+ − 115 and type @kbd{C-k} twice.
+ − 116
+ − 117 More generally, @kbd{C-k} kills from point up to the end of the line,
+ − 118 unless it is at the end of a line. In that case, it kills the newline
+ − 119 following the line, thus merging the next line into the current one.
+ − 120 Emacs ignores invisible spaces and tabs at the end of the line when deciding
+ − 121 which case applies: if point appears to be at the end of the line, you
+ − 122 can be sure the newline will be killed.
+ − 123
+ − 124 If you give @kbd{C-k} a positive argument, it kills that many lines
+ − 125 and the newlines that follow them (however, text on the current line
+ − 126 before point is not killed). With a negative argument, @kbd{C-k} kills
+ − 127 back to a number of line beginnings. An argument of @minus{}2 means
+ − 128 kill back to the second line beginning. If point is at the beginning of
+ − 129 a line, that line beginning doesn't count, so @kbd{C-u - 2 C-k} with
+ − 130 point at the front of a line kills the two previous lines.
+ − 131
+ − 132 @kbd{C-k} with an argument of zero kills all the text before point on the
+ − 133 current line.
+ − 134
+ − 135 @subsection Other Kill Commands
+ − 136 @findex kill-region
+ − 137 @findex kill-word
+ − 138 @findex backward-kill-word
+ − 139 @findex kill-sexp
+ − 140 @findex kill-sentence
+ − 141 @findex backward-kill-sentence
+ − 142 @kindex M-d
+ − 143 @kindex M-DEL
+ − 144 @kindex C-M-k
+ − 145 @kindex C-x DEL
+ − 146 @kindex M-k
+ − 147 @kindex C-w
+ − 148
+ − 149 @c DoubleWideCommands
+ − 150 @table @kbd
+ − 151 @item C-w
+ − 152 Kill region (from point to the mark) (@code{kill-region}).
+ − 153 @xref{Words}.
+ − 154 @item M-d
+ − 155 Kill word (@code{kill-word}).
+ − 156 @item M-@key{DEL}
+ − 157 Kill word backwards (@code{backward-kill-word}).
+ − 158 @item C-x @key{DEL}
+ − 159 Kill back to beginning of sentence (@code{backward-kill-sentence}).
+ − 160 @xref{Sentences}.
+ − 161 @item M-k
+ − 162 Kill to end of sentence (@code{kill-sentence}).
+ − 163 @item C-M-k
+ − 164 Kill sexp (@code{kill-sexp}). @xref{Lists}.
+ − 165 @item M-z @var{char}
+ − 166 Kill up to next occurrence of @var{char} (@code{zap-to-char}).
+ − 167 @end table
+ − 168
+ − 169 @kbd{C-w} (@code{kill-region}) is a very general kill command; it
+ − 170 kills everything between point and the mark. You can use this command to
+ − 171 kill any contiguous sequence of characters by first setting the mark at
+ − 172 one end of a sequence of characters, then going to the other end and
+ − 173 typing @kbd{C-w}.
+ − 174
+ − 175 @kindex M-z
+ − 176 @findex zap-to-char
+ − 177 A convenient way of killing is combined with searching: @kbd{M-z}
+ − 178 (@code{zap-to-char}) reads a character and kills from point up to (but not
+ − 179 including) the next occurrence of that character in the buffer. If there
+ − 180 is no next occurrence, killing goes to the end of the buffer. A numeric
+ − 181 argument acts as a repeat count. A negative argument means to search
+ − 182 backward and kill text before point.
+ − 183
+ − 184 Other syntactic units can be killed: words, with @kbd{M-@key{DEL}} and
+ − 185 @kbd{M-d} (@pxref{Words}); sexps, with @kbd{C-M-k} (@pxref{Lists}); and
+ − 186 sentences, with @kbd{C-x @key{DEL}} and @kbd{M-k}
+ − 187 (@pxref{Sentences}).@refill
+ − 188
+ − 189 @node Yanking, Using X Selections, Killing, Top
+ − 190 @section Yanking
+ − 191 @cindex moving text
+ − 192 @cindex copying text
+ − 193 @cindex kill ring
+ − 194 @cindex yanking
+ − 195 @cindex pasting
+ − 196
+ − 197 @dfn{Yanking} means getting back text which was killed. Some systems
+ − 198 call this ``pasting''. The usual way to move or copy text is to kill it
+ − 199 and then yank it one or more times.
+ − 200
+ − 201 @table @kbd
+ − 202 @item C-y
+ − 203 Yank last killed text (@code{yank}).
+ − 204 @item M-y
+ − 205 Replace re-inserted killed text with the previously killed text
+ − 206 (@code{yank-pop}).
+ − 207 @item M-w
+ − 208 Save region as last killed text without actually killing it
+ − 209 (@code{copy-region-as-kill}).
+ − 210 @item C-M-w
+ − 211 Append next kill to last batch of killed text (@code{append-next-kill}).
+ − 212 @end table
+ − 213
+ − 214 @menu
+ − 215 * Kill Ring:: Where killed text is stored. Basic yanking.
+ − 216 * Appending Kills:: Several kills in a row all yank together.
+ − 217 * Earlier Kills:: Yanking something killed some time ago.
+ − 218 @end menu
+ − 219
+ − 220 @node Kill Ring, Appending Kills, Yanking, Yanking
+ − 221 @subsection The Kill Ring
+ − 222
+ − 223 @kindex C-y
+ − 224 @findex Yank
+ − 225 All killed text is recorded in the @dfn{kill ring}, a list of blocks of
+ − 226 text that have been killed. There is only one kill ring, used in all
+ − 227 buffers, so you can kill text in one buffer and yank it in another buffer.
+ − 228 This is the usual way to move text from one file to another.
+ − 229 (@xref{Accumulating Text}, for some other ways.)
+ − 230
+ − 231 If you have two separate Emacs processes, you cannot use the kill ring
+ − 232 to move text. If you are using XEmacs under X, however, you can
+ − 233 use the X selection mechanism to move text from one to another.
+ − 234
+ − 235 If you are using XEmacs under X and have one Emacs process with
+ − 236 multiple frames, they do share the same kill ring. You can kill or
+ − 237 copy text in one Emacs frame, then yank it in the other frame
+ − 238 belonging to the same process.
+ − 239
+ − 240 The command @kbd{C-y} (@code{yank}) reinserts the text of the most recent
+ − 241 kill. It leaves the cursor at the end of the text and sets the mark at
+ − 242 the beginning of the text. @xref{Mark}.
+ − 243
+ − 244 @kbd{C-u C-y} yanks the text, leaves the cursor in front of the text,
+ − 245 and sets the mark after it, if the argument is with just a @kbd{C-u}.
+ − 246 Any other argument, including @kbd{C-u} and digits, has different
+ − 247 results, described below, under ``Yanking Earlier Kills''.
+ − 248
+ − 249 @kindex M-w
+ − 250 @findex copy-region-as-kill
+ − 251 To copy a block of text, you can also use @kbd{M-w}
+ − 252 (@code{copy-region-as-kill}), which copies the region into the kill ring
+ − 253 without removing it from the buffer. @kbd{M-w} is similar to @kbd{C-w}
+ − 254 followed by @kbd{C-y} but does not mark the buffer as ``modified'' and
+ − 255 does not actually cut anything.
+ − 256
+ − 257 @node Appending Kills, Earlier Kills, Kill Ring, Yanking
+ − 258 @subsection Appending Kills
+ − 259
+ − 260 @cindex television
+ − 261 Normally, each kill command pushes a new block onto the kill ring.
+ − 262 However, two or more kill commands in a row combine their text into a
+ − 263 single entry, so that a single @kbd{C-y} yanks it all back. This means
+ − 264 you don't have to kill all the text you want to yank in one command; you
+ − 265 can kill line after line, or word after word, until you have killed what
+ − 266 you want, then get it all back at once using @kbd{C-y}. (Thus we join
+ − 267 television in leading people to kill thoughtlessly.)
+ − 268
+ − 269 Commands that kill forward from point add onto the end of the previous
+ − 270 killed text. Commands that kill backward from point add onto the
+ − 271 beginning. This way, any sequence of mixed forward and backward kill
+ − 272 commands puts all the killed text into one entry without rearrangement.
+ − 273 Numeric arguments do not break the sequence of appending kills. For
+ − 274 example, suppose the buffer contains:
+ − 275
+ − 276 @example
+ − 277 This is the first
+ − 278 line of sample text
+ − 279 and here is the third.
+ − 280 @end example
+ − 281
+ − 282 @noindent
+ − 283 with point at the beginning of the second line. If you type @kbd{C-k C-u 2
+ − 284 M-@key{DEL} C-k}, the first @kbd{C-k} kills the text @samp{line of sample
+ − 285 text}, @kbd{C-u 2 M-@key{DEL}} kills @samp{the first} with the newline that
+ − 286 followed it, and the second @kbd{C-k} kills the newline after the second
+ − 287 line. The result is that the buffer contains @samp{This is and here is the
+ − 288 third.} and a single kill entry contains @samp{the first@key{RET}line of
+ − 289 sample text@key{RET}}---all the killed text, in its original order.
+ − 290
+ − 291 @kindex C-M-w
+ − 292 @findex append-next-kill
+ − 293 If a kill command is separated from the last kill command by other
+ − 294 commands (not just numeric arguments), it starts a new entry on the kill
+ − 295 ring. To force a kill command to append, first type the command @kbd{C-M-w}
+ − 296 (@code{append-next-kill}). @kbd{C-M-w} tells the following command,
+ − 297 if it is a kill command, to append the text it kills to the last killed
+ − 298 text, instead of starting a new entry. With @kbd{C-M-w}, you can kill
+ − 299 several separated pieces of text and accumulate them to be yanked back
+ − 300 in one place.@refill
+ − 301
+ − 302 @node Earlier Kills,, Appending Kills, Yanking
+ − 303 @subsection Yanking Earlier Kills
+ − 304
+ − 305 @kindex M-y
+ − 306 @findex yank-pop
+ − 307 To recover killed text that is no longer the most recent kill, you need
+ − 308 the @kbd{Meta-y} (@code{yank-pop}) command. You can use @kbd{M-y} only
+ − 309 after a @kbd{C-y} or another @kbd{M-y}. It takes the text previously
+ − 310 yanked and replaces it with the text from an earlier kill. To recover
+ − 311 the text of the next-to-the-last kill, first use @kbd{C-y} to recover
+ − 312 the last kill, then @kbd{M-y} to replace it with the previous
+ − 313 kill.@refill
+ − 314
+ − 315 You can think in terms of a ``last yank'' pointer which points at an item
+ − 316 in the kill ring. Each time you kill, the ``last yank'' pointer moves to
+ − 317 the new item at the front of the ring. @kbd{C-y} yanks the item
+ − 318 which the ``last yank'' pointer points to. @kbd{M-y} moves the ``last
+ − 319 yank'' pointer to a different item, and the text in the buffer changes to
+ − 320 match. Enough @kbd{M-y} commands can move the pointer to any item in the
+ − 321 ring, so you can get any item into the buffer. Eventually the pointer
+ − 322 reaches the end of the ring; the next @kbd{M-y} moves it to the first item
+ − 323 again.
+ − 324
+ − 325 Yanking moves the ``last yank'' pointer around the ring, but does not
+ − 326 change the order of the entries in the ring, which always runs from the
+ − 327 most recent kill at the front to the oldest one still remembered.
+ − 328
+ − 329 Use @kbd{M-y} with a numeric argument to advance the ``last
+ − 330 yank'' pointer by the specified number of items. A negative argument
+ − 331 moves the pointer toward the front of the ring; from the front of the
+ − 332 ring, it moves to the last entry and starts moving forward from there.
+ − 333
+ − 334 Once the text you are looking for is brought into the buffer, you can
+ − 335 stop doing @kbd{M-y} commands and the text will stay there. Since the
+ − 336 text is just a copy of the kill ring item, editing it in the buffer does
+ − 337 not change what's in the ring. As long you don't kill additional text,
+ − 338 the ``last yank'' pointer remains at the same place in the kill ring:
+ − 339 repeating @kbd{C-y} will yank another copy of the same old kill.
+ − 340
+ − 341 If you know how many @kbd{M-y} commands it would take to find the
+ − 342 text you want, you can yank that text in one step using @kbd{C-y} with
+ − 343 a numeric argument. @kbd{C-y} with an argument greater than one
+ − 344 restores the text the specified number of entries back in the kill
+ − 345 ring. Thus, @kbd{C-u 2 C-y} gets the next to the last block of killed
+ − 346 text. It is equivalent to @kbd{C-y M-y}. @kbd{C-y} with a numeric
+ − 347 argument starts counting from the ``last yank'' pointer, and sets the
+ − 348 ``last yank'' pointer to the entry that it yanks.
+ − 349
+ − 350 @vindex kill-ring-max
+ − 351 The variable @code{kill-ring-max} controls the length of the kill
+ − 352 ring; no more than that many blocks of killed text are saved.
+ − 353
+ − 354 @node Using X Selections, Accumulating Text, Yanking, Top
+ − 355 @section Using X Selections
+ − 356 @comment node-name, next, previous, up
+ − 357
+ − 358 In the X window system, mouse selections provide a simple mechanism for
+ − 359 text transfer between different applications. In a typical X
+ − 360 application, you can select text by pressing the left mouse button and
+ − 361 dragging the cursor over the text you want to copy. The text becomes the
+ − 362 primary X selection and is highlighted. The highlighted region is also
+ − 363 the Emacs selected region.
+ − 364
+ − 365 @itemize @bullet
+ − 366 @item
+ − 367 Since the region is the primary X selection, you can go to a different X
+ − 368 application and click the middle mouse button: the text that you selected in
+ − 369 the previous application is pasted into the current application.
+ − 370 @item
+ − 371 Since the region is the Emacs selected region, you can use all region
+ − 372 commands (@kbd{C-w, M-w} etc.) as well as the options of the @b{Edit}
+ − 373 menu to manipulate the selected text.
+ − 374 @end itemize
+ − 375
+ − 376 @menu
+ − 377 * X Clipboard Selection:: Pasting to the X clipboard.
+ − 378 * X Selection Commands:: Other operations on the selection.
+ − 379 * X Cut Buffers:: X cut buffers are available for compatibility.
+ − 380 * Active Regions:: Using zmacs-style highlighting of the
+ − 381 selected region.
+ − 382 @end menu
+ − 383
+ − 384 @node X Clipboard Selection, X Selection Commands, Using X Selections, Using X Selections
+ − 385 @comment node-name, next, previous, up
+ − 386 @subsection The Clipboard Selection
+ − 387 @cindex clipboard selections
+ − 388
+ − 389 There are other kinds of X selections besides the @b{Primary} selection; one
+ − 390 common one is the @b{Clipboard} selection. Some applications prefer to
+ − 391 transfer data using this selection in preference to the @b{Primary}.
+ − 392 One can transfer text from the @b{Primary} selection to the @b{Clipboard}
+ − 393 selection with the @b{Copy} command under the @b{Edit} menu in the menubar.
+ − 394
+ − 395 Usually, the clipboard selection is not visible. However, if you run the
+ − 396 @file{xclipboard} application, the text most recently copied to the clipboard
+ − 397 (with the @b{Copy} command) is displayed in a window. Any time new text is
+ − 398 thus copied, the @file{xclipboard} application makes a copy of it and displays
+ − 399 it in its window. The value of the clipboard can survive the lifetime of the
+ − 400 running Emacs process. The @code{xclipboard} man page provides more details.
+ − 401
+ − 402 Warning: If you use the @file{xclipboard} application, remember that it
+ − 403 maintains a list of all things that have been pasted to the clipboard (that
+ − 404 is, copied with the @b{Copy} command). If you don't manually delete elements
+ − 405 from this list by clicking on the @b{Delete} button in the @code{xclipboard}
+ − 406 window, the clipboard will eventually consume a lot of memory.
+ − 407
+ − 408 In summary, some X applications (such as @file{xterm}) allow one to paste
+ − 409 text in them from XEmacs in the following way:
+ − 410
+ − 411 @itemize @bullet
+ − 412 @item
+ − 413 Drag out a region of text in Emacs with the left mouse button,
+ − 414 making that text be the @b{Primary} selection.
+ − 415
+ − 416 @item
+ − 417 Click the middle button in the other application, pasting the @b{Primary}
+ − 418 selection.
+ − 419 @end itemize
+ − 420
+ − 421 With some other applications (notably, the OpenWindows and Motif tools) you
+ − 422 must use this method instead:
+ − 423
+ − 424 @itemize @bullet
+ − 425 @item
+ − 426 Drag out a region of text in Emacs with the left mouse button,
+ − 427 making that text be the @b{Primary} selection.
+ − 428
+ − 429 @item
+ − 430 Copy the selected text to the @b{Clipboard} selection by selecting the
+ − 431 @b{Copy} menu item from the @b{Edit} menu, or by hitting the @b{Copy}
+ − 432 key on your keyboard.
+ − 433
+ − 434 @item
+ − 435 Paste the text in the other application by selecting @b{Paste} from its
+ − 436 menu, or by hitting the @b{Paste} key on your keyboard.
+ − 437 @end itemize
+ − 438
+ − 439
+ − 440 @node X Selection Commands, X Cut Buffers, X Clipboard Selection, Using X Selections
+ − 441 @subsection Miscellaneous X Selection Commands
+ − 442 @comment node-name, next, previous, up
+ − 443 @cindex cut buffers
+ − 444 @cindex primary selections
+ − 445
+ − 446 @findex x-copy-primary-selection
+ − 447 @findex x-delete-primary-selection
+ − 448 @findex x-insert-selection
+ − 449 @findex x-kill-primary-selection
+ − 450 @findex x-mouse-kill
+ − 451 @findex x-own-secondary-selection
+ − 452 @findex x-own-selection
+ − 453 @findex x-set-point-and-insert-selection
+ − 454 @table @kbd
+ − 455 @item M-x x-copy-primary-selection
+ − 456 Copy the primary selection to both the kill ring and the Clipboard.
+ − 457 @item M-x x-insert-selection
+ − 458 Insert the current selection into the buffer at point.
+ − 459 @item M-x x-delete-primary-selection
+ − 460 Deletes the text in the primary selection without copying it to the kill
+ − 461 ring or the Clipboard.
+ − 462 @item M-x x-kill-primary-selection
+ − 463 Deletes the text in the primary selection and copies it to
+ − 464 both the kill ring and the Clipboard.
+ − 465 @item M-x x-mouse-kill
+ − 466 Kill the text between point and the mouse and copy it to
+ − 467 the clipboard and to the cut buffer.
+ − 468 @item M-x x-own-secondary-selection
+ − 469 Make a secondary X selection of the given argument.
+ − 470 @item M-x x-own-selection
+ − 471 Make a primary X selection of the given argument.
+ − 472 @item M-x x-set-point-and-insert-selection
+ − 473 Set point where clicked and insert the primary selection or the
+ − 474 cut buffer.
+ − 475 @end table
+ − 476
+ − 477 @node X Cut Buffers, Active Regions, X Selection Commands, Using X Selections
+ − 478 @subsection X Cut Buffers
+ − 479 @comment node-name, next, previous, up
+ − 480
+ − 481 X cut buffers are a different, older way of transferring text between
+ − 482 applications. XEmacs supports cut buffers for compatibility
+ − 483 with older programs, even though selections are now the preferred way of
+ − 484 transferring text.
+ − 485
+ − 486 X has a concept of applications "owning" selections. When you select
+ − 487 text by clicking and dragging inside an application, the application
+ − 488 tells the X server that it owns the selection. When another
+ − 489 application asks the X server for the value of the selection, the X
+ − 490 server requests the information from the owner. When you use
+ − 491 selections, the selection data is not actually transferred unless
+ − 492 someone wants it; the act of making a selection doesn't transfer data.
+ − 493 Cut buffers are different: when you "own" a cut buffer, the data is
+ − 494 actually transferred to the X server immediately, and survives the
+ − 495 lifetime of the application.
+ − 496
+ − 497 Any time a region of text becomes the primary selection in Emacs,
+ − 498 Emacs also copies that text to the cut buffer. This makes it possible
+ − 499 to copy text from an XEmacs buffer and paste it into an older,
+ − 500 non-selection-based application (such as Emacs 18).
+ − 501
+ − 502 Note: Older versions of Emacs could not access the X selections, only
+ − 503 the X cut buffers.
+ − 504
+ − 505 @node Active Regions, , X Cut Buffers, Using X Selections
+ − 506 @subsection Active Regions
+ − 507 @comment node-name, next, previous, up
+ − 508 @cindex active regions
+ − 509
+ − 510 By default, both the text you select in an Emacs buffer using the
+ − 511 click-and-drag mechanism and text you select by setting point and the
+ − 512 mark is highlighted. You can use Emacs region commands as well as the
+ − 513 @b{Cut} and @b{Copy} commands on the highlighted region you selected
+ − 514 with the mouse.
+ − 515
+ − 516 If you prefer, you can make a distinction between text selected with the
+ − 517 mouse and text selected with point and the mark by setting the variable
+ − 518 @code{zmacs-regions} to @code{nil}. In that case:
+ − 519
+ − 520 @itemize @bullet
+ − 521 @item
+ − 522 The text selected with the mouse becomes both the X selection and the
+ − 523 Emacs selected region. You can use menu-bar commands as well as Emacs
+ − 524 region commands on it.
+ − 525 @item
+ − 526 The text selected with point and the mark is not highlighted. You can
+ − 527 only use Emacs region commands on it, not the menu-bar items.
+ − 528 @end itemize
+ − 529
+ − 530 Active regions originally come from Zmacs, the Lisp Machine editor.
+ − 531 The idea behind them is that commands can only operate on a region when
+ − 532 the region is in an "active" state. Put simply, you can only operate on
+ − 533 a region that is highlighted.
+ − 534
+ − 535 @vindex zmacs-regions
+ − 536 The variable @code{zmacs-regions} checks whether LISPM-style active
+ − 537 regions should be used. This means that commands that operate on the
+ − 538 region (the area between point and the mark) only work while
+ − 539 the region is in the active state, which is indicated by highlighting.
+ − 540 Most commands causes the region to not be in the active state;
+ − 541 for example, @kbd{C-w} only works immediately after activating the
+ − 542 region.
+ − 543
+ − 544 More specifically:
+ − 545 @itemize @bullet
+ − 546 @item
+ − 547 Commands that operate on the region only work if the region is active.
+ − 548 @item
+ − 549 Only a very small set of commands causes the region to become active---
+ − 550 those commands whose semantics are to mark an area, such as @code{mark-defun}.
+ − 551 @item
+ − 552 The region is deactivated after each command that is executed, except that
+ − 553 motion commands do not change whether the region is active or not.
+ − 554 @end itemize
+ − 555
+ − 556 @code{set-mark-command} (@kbd{C-SPC}) pushes a mark and activates the
+ − 557 region. Moving the cursor with normal motion commands (@kbd{C-n},
+ − 558 @kbd{C-p}, etc.) will cause the region between point and the
+ − 559 recently-pushed mark to be highlighted. It will remain highlighted
+ − 560 until some non-motion command is executed.
+ − 561
+ − 562 @code{exchange-point-and-mark} (@kbd{C-x C-x}) activates the region.
+ − 563 So if you mark a region and execute a command that operates on it, you
+ − 564 can reactivate the same region with @kbd{C-x C-x} (or perhaps @kbd{C-x
+ − 565 C-x C-x C-x}) to operate on it again.
+ − 566
+ − 567 Generally, commands that push marks as a means of navigation, such as
+ − 568 @code{beginning-of-buffer} (@kbd{M-<}) and @code{end-of-buffer}
+ − 569 (@kbd{M->}), do not activate the region. However, commands that push
+ − 570 marks as a means of marking an area of text, such as @code{mark-defun}
+ − 571 (@kbd{M-C-h}), @code{mark-word} (@kbd{M-@@}), and @code{mark-whole-buffer}
+ − 572 (@kbd{C-x h}), do activate the region.
+ − 573
+ − 574 When @code{zmacs-regions} is @code{t}, there is no distinction between
+ − 575 the primary X selection and the active region selected by point and the
+ − 576 mark. To see this, set the mark (@key{C-SPC}) and move the cursor
+ − 577 with any cursor-motion command: the region between point and mark is
+ − 578 highlighted, and you can watch it grow and shrink as you move the
+ − 579 cursor.
+ − 580
+ − 581 Any other commands besides cursor-motion commands (such as inserting or
+ − 582 deleting text) will cause the region to no longer be active; it will no
+ − 583 longer be highlighted, and will no longer be the primary selection.
+ − 584 Region can be explicitly deactivated with @kbd{C-g}.
+ − 585
+ − 586 Commands that require a region (such as @kbd{C-w}) signal an error if
+ − 587 the region is not active. Certain commands cause the region to be in
+ − 588 its active state. The most common ones are @code{push-mark}
+ − 589 (@key{C-SPC}) and @code{exchange-point-and-mark} (@kbd{C-x C-x}).
+ − 590
+ − 591 @vindex zmacs-region-stays
+ − 592 When @code{zmacs-regions} is @code{t}, programs can be non-intrusive
+ − 593 on the state of the region by setting the variable @code{zmacs-region-stays}
+ − 594 to a non-@code{nil} value. If you are writing a new Emacs command that
+ − 595 is conceptually a ``motion'' command and should not interfere with the
+ − 596 current highlightedness of the region, then you may set this variable.
+ − 597 It is reset to @code{nil} after each user command is executed.
+ − 598
+ − 599 @findex zmacs-activate-region
+ − 600 When @code{zmacs-regions} is @code{t}, programs can make the region between
+ − 601 point and mark go into the active (highlighted) state by using the
+ − 602 function @code{zmacs-activate-region}. Only a small number of commands
+ − 603 should ever do this.
+ − 604
+ − 605 @findex zmacs-deactivate-region
+ − 606 When @code{zmacs-regions} is @code{t}, programs can deactivate the region
+ − 607 between point and the mark by using @code{zmacs-deactivate-region}.
+ − 608 Note: you should not have to call this function; the command loop calls
+ − 609 it when appropriate.
+ − 610
+ − 611 @node Accumulating Text, Rectangles, Using X Selections, Top
+ − 612 @section Accumulating Text
+ − 613 @findex append-to-buffer
+ − 614 @findex prepend-to-buffer
+ − 615 @findex copy-to-buffer
+ − 616 @findex append-to-file
+ − 617 @cindex copying text
+ − 618 @cindex accumulating text
+ − 619
+ − 620 Usually you copy or move text by killing it and yanking it, but there are
+ − 621 other ways that are useful for copying one block of text in many places, or
+ − 622 for copying many scattered blocks of text into one place.
+ − 623
+ − 624 If you like, you can accumulate blocks of text from scattered
+ − 625 locations either into a buffer or into a file. The relevant commands
+ − 626 are described here. You can also use Emacs registers for storing and
+ − 627 accumulating text. @xref{Registers}.
+ − 628
+ − 629 @table @kbd
+ − 630 @item M-x append-to-buffer
+ − 631 Append region to contents of specified buffer (@code{append-to-buffer}).
+ − 632 @item M-x prepend-to-buffer
+ − 633 Prepend region to contents of specified buffer.
+ − 634 @item M-x copy-to-buffer
+ − 635 Copy region into specified buffer, deleting that buffer's old contents.
+ − 636 @item M-x insert-buffer
+ − 637 Insert contents of specified buffer into current buffer at point.
+ − 638 @item M-x append-to-file
+ − 639 Append region to the end of the contents of specified file.
+ − 640 @end table
+ − 641
+ − 642 To accumulate text into a buffer, use the command @kbd{M-x
+ − 643 append-to-buffer}, which inserts a copy of the region into the buffer
+ − 644 @var{buffername}, at the location of point in that buffer. If there is
+ − 645 no buffer with the given name, one is created.
+ − 646
+ − 647 If you append text to a buffer that has been used for editing, the
+ − 648 copied text goes to the place where point is. Point in that buffer is
+ − 649 left at the end of the copied text, so successive uses of
+ − 650 @code{append-to-buffer} accumulate the text in the specified buffer in
+ − 651 the same order as they were copied. Strictly speaking, this command does
+ − 652 not always append to the text already in the buffer; but if this command
+ − 653 is the only command used to alter a buffer, it does always append to the
+ − 654 existing text because point is always at the end.
+ − 655
+ − 656 @kbd{M-x prepend-to-buffer} is similar to @code{append-to-buffer}, but
+ − 657 point in the other buffer is left before the copied text, so successive
+ − 658 prependings add text in reverse order. @kbd{M-x copy-to-buffer} is
+ − 659 similar, except that any existing text in the other buffer is deleted,
+ − 660 so the buffer is left containing just the text newly copied into it.
+ − 661
+ − 662 You can retrieve the accumulated text from that buffer with @kbd{M-x
+ − 663 insert-buffer}, which takes @var{buffername} as an argument. It inserts
+ − 664 a copy of the text in buffer @var{buffername} into the selected buffer.
+ − 665 You could alternatively select the other buffer for editing, perhaps moving
+ − 666 text from it by killing or with @code{append-to-buffer}. @xref{Buffers}, for
+ − 667 background information on buffers.
+ − 668
+ − 669 Instead of accumulating text within Emacs in a buffer, you can append
+ − 670 text directly into a file with @kbd{M-x append-to-file}, which takes
+ − 671 @var{file-name} as an argument. It adds the text of the region to the
+ − 672 end of the specified file. The file is changed immediately on disk.
+ − 673 This command is normally used with files that are @i{not} being visited
+ − 674 in Emacs. Using it on a file that Emacs is visiting can produce
+ − 675 confusing results, because the file's text inside Emacs does not change
+ − 676 while the file itself changes.
+ − 677
+ − 678 @node Rectangles, Registers, Accumulating Text, Top
+ − 679 @section Rectangles
+ − 680 @cindex rectangles
+ − 681
+ − 682 The rectangle commands affect rectangular areas of text: all
+ − 683 characters between a certain pair of columns, in a certain range of lines.
+ − 684 Commands are provided to kill rectangles, yank killed rectangles, clear
+ − 685 them out, or delete them. Rectangle commands are useful with text in
+ − 686 multicolumnar formats, like code with comments at the right,
+ − 687 or for changing text into or out of such formats.
+ − 688
+ − 689 To specify the rectangle a command should work on, put the mark at one
+ − 690 corner and point at the opposite corner. The specified rectangle is
+ − 691 called the @dfn{region-rectangle} because it is controlled about the
+ − 692 same way the region is controlled. Remember that a given
+ − 693 combination of point and mark values can be interpreted either as
+ − 694 specifying a region or as specifying a rectangle; it is up to the
+ − 695 command that uses them to choose the interpretation.
+ − 696
+ − 697 @table @kbd
+ − 698 @item M-x delete-rectangle
+ − 699 Delete the text of the region-rectangle, moving any following text on
+ − 700 each line leftward to the left edge of the region-rectangle.
+ − 701 @item M-x kill-rectangle
+ − 702 Similar, but also save the contents of the region-rectangle as the
+ − 703 ``last killed rectangle''.
+ − 704 @item M-x yank-rectangle
+ − 705 Yank the last killed rectangle with its upper left corner at point.
+ − 706 @item M-x open-rectangle
+ − 707 Insert blank space to fill the space of the region-rectangle.
+ − 708 The previous contents of the region-rectangle are pushed rightward.
+ − 709 @item M-x clear-rectangle
+ − 710 Clear the region-rectangle by replacing its contents with spaces.
+ − 711 @end table
+ − 712
+ − 713 The rectangle operations fall into two classes: commands deleting and
+ − 714 moving rectangles, and commands for blank rectangles.
+ − 715
+ − 716 @findex delete-rectangle
+ − 717 @findex kill-rectangle
+ − 718 There are two ways to get rid of the text in a rectangle: you can discard
+ − 719 the text (delete it) or save it as the ``last killed'' rectangle. The
+ − 720 commands for these two ways are @kbd{M-x delete-rectangle} and @kbd{M-x
+ − 721 kill-rectangle}. In either case, the portion of each line that falls inside
+ − 722 the rectangle's boundaries is deleted, causing following text (if any) on
+ − 723 the line to move left.
+ − 724
+ − 725 Note that ``killing'' a rectangle is not killing in the usual sense; the
+ − 726 rectangle is not stored in the kill ring, but in a special place that
+ − 727 only records the most recently killed rectangle (that is, does not
+ − 728 append to a killed rectangle). Different yank commands
+ − 729 have to be used and only one rectangle is stored, because yanking
+ − 730 a rectangle is quite different from yanking linear text and yank-popping
+ − 731 commands are difficult to make sense of.
+ − 732
+ − 733 Inserting a rectangle is the opposite of deleting one. You specify
+ − 734 where to put the upper left corner by putting point there. The
+ − 735 rectangle's first line is inserted at point, the rectangle's second line
+ − 736 is inserted at a point one line vertically down, and so on. The number
+ − 737 of lines affected is determined by the height of the saved rectangle.
+ − 738
+ − 739 @findex yank-rectangle
+ − 740 To insert the last killed rectangle, type @kbd{M-x yank-rectangle}.
+ − 741 This can be used to convert single-column lists into double-column
+ − 742 lists; kill the second half of the list as a rectangle and then
+ − 743 yank it beside the first line of the list.
+ − 744
+ − 745 @findex open-rectangle
+ − 746 @findex clear-rectangle
+ − 747 There are two commands for working with blank rectangles: @kbd{M-x
+ − 748 clear-rectangle} erases existing text, and @kbd{M-x open-rectangle}
+ − 749 inserts a blank rectangle. Clearing a rectangle is equivalent to
+ − 750 deleting it and then inserting a blank rectangle of the same size.
+ − 751
+ − 752 Rectangles can also be copied into and out of registers.
+ − 753 @xref{RegRect,,Rectangle Registers}.
