1 @c This is part of the Emacs manual.
2 @c Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 2001, 2002,
3 @c 2003, 2004, 2005 Free Software Foundation, Inc.
4 @c See file emacs.texi for copying conditions.
5 @node Mark, Killing, Help, Top
6 @chapter The Mark and the Region
11 Many Emacs commands operate on an arbitrary contiguous part of the
12 current buffer. To specify the text for such a command to operate on,
13 you set @dfn{the mark} at one end of it, and move point to the other
14 end. The text between point and the mark is called @dfn{the region}.
15 Emacs highlights the region whenever there is one, if you enable
16 Transient Mark mode (@pxref{Transient Mark}).
18 Certain Emacs commands set the mark; other editing commands do not
19 affect it, so the mark remains where you set it last. Each Emacs
20 buffer has its own mark, and setting the mark in one buffer has no
21 effect on other buffers' marks. When you return to a buffer that was
22 current earlier, its mark is at the same place as before.
24 The ends of the region are always point and the mark. It doesn't
25 matter which of them was put in its current place first, or which one
26 comes earlier in the text---the region starts from point or the mark
27 (whichever comes first), and ends at point or the mark (whichever
28 comes last). Every time you move point, or set the mark in a new
29 place, the region changes.
31 Many commands that insert text, such as @kbd{C-y} (@code{yank}) and
32 @kbd{M-x insert-buffer}, position point and the mark at opposite ends
33 of the inserted text, so that the region consists of the text just
36 Aside from delimiting the region, the mark is also useful for
37 remembering a spot that you may want to go back to. To make this
38 feature more useful, each buffer remembers 16 previous locations of the
39 mark in the @dfn{mark ring}.
42 * Setting Mark:: Commands to set the mark.
43 * Transient Mark:: How to make Emacs highlight the region--
45 * Momentary Mark:: Enabling Transient Mark mode momentarily.
46 * Using Region:: Summary of ways to operate on contents of the region.
47 * Selective Undo:: Undoing within a given region.
48 * Marking Objects:: Commands to put region around textual units.
49 * Mark Ring:: Previous mark positions saved so you can go back there.
50 * Global Mark Ring:: Previous mark positions in various buffers.
54 @section Setting the Mark
56 Here are some commands for setting the mark:
60 Set the mark where point is (@code{set-mark-command}).
64 Interchange mark and point (@code{exchange-point-and-mark}).
66 Set point and the mark around the text you drag across.
68 Set the mark where point is, then move point to where you click
69 (@code{mouse-save-then-kill}).
72 For example, suppose you wish to convert part of the buffer to
73 upper case, using the @kbd{C-x C-u} (@code{upcase-region}) command,
74 which operates on the text in the region. You can first go to the
75 beginning of the text to be capitalized, type @kbd{C-@key{SPC}} to put
76 the mark there, move to the end, and then type @kbd{C-x C-u}. Or, you
77 can set the mark at the end of the text, move to the beginning, and then
81 @findex set-mark-command
82 The most common way to set the mark is with the @kbd{C-@key{SPC}} command
83 (@code{set-mark-command}). This sets the mark where point is. Then you
84 can move point away, leaving the mark behind.
86 There are two ways to set the mark with the mouse. You can drag mouse
87 button one across a range of text; that puts point where you release the
88 mouse button, and sets the mark at the other end of that range. Or you
89 can click mouse button three, which sets the mark at point (like
90 @kbd{C-@key{SPC}}) and then moves point where you clicked (like
91 @kbd{Mouse-1}). Both of these methods copy the region into the kill
92 ring in addition to setting the mark; that gives behavior consistent
93 with other window-driven applications, but if you don't want to modify
94 the kill ring, you must use keyboard commands to set the mark.
95 @xref{Mouse Commands}.
98 @findex exchange-point-and-mark
99 When Emacs was developed, terminals had only one cursor, so Emacs
100 does not show where the mark is located--you have to remember. If you
101 enable Transient Mark mode (see below), then the region is highlighted
102 when it is active; you can tell mark is at the other end of the
103 highlighted region. But this only applies when the mark is active.
105 The usual solution to this problem is to set the mark and then use
106 it soon, before you forget where it is. Alternatively, you can see
107 where the mark is with the command @kbd{C-x C-x}
108 (@code{exchange-point-and-mark}) which puts the mark where point was
109 and point where the mark was. The extent of the region is unchanged,
110 but the cursor and point are now at the previous position of the mark.
111 In Transient Mark mode, this command also reactivates the mark.
113 @kbd{C-x C-x} is also useful when you are satisfied with the position
114 of point but want to move the other end of the region (where the mark
115 is); do @kbd{C-x C-x} to put point at that end of the region, and then
116 move it. Using @kbd{C-x C-x} a second time, if necessary, puts the mark at
117 the new position with point back at its original position.
119 For more facilities that allow you to go to previously set marks, see
123 There is no such character as @kbd{C-@key{SPC}} in @acronym{ASCII};
124 when you type @key{SPC} while holding down @key{CTRL} on a text
125 terminal, what you get is the character @kbd{C-@@}. This key is also
126 bound to @code{set-mark-command}--so unless you are unlucky enough to
127 have a text terminal where typing @kbd{C-@key{SPC}} does not produce
128 @kbd{C-@@}, you might as well think of this character as
132 @section Transient Mark Mode
133 @cindex mode, Transient Mark
134 @cindex Transient Mark mode
135 @cindex highlighting region
136 @cindex region highlighting
138 On a terminal that supports colors, Emacs has the ability to
139 highlight the current region. But normally it does not. Why not?
141 Once you have set the mark in a buffer, there is @emph{always} a
142 region in that buffer. This is because every command that sets the
143 mark also activates it, and nothing ever deactivates it. Highlighting
144 the region all the time would be a nuisance. So normally Emacs
145 highlights the region only immediately after you have selected one
148 If you want region highlighting, you can use Transient Mark mode.
149 This is a more rigid mode of operation in which the region always
150 ``lasts'' only until you use it; you explicitly must set up a region
151 for each command that uses one. In Transient Mark mode, most of the
152 time there is no region; therefore, highlighting the region when it
153 exists is useful and not annoying. When Transient Mark mode is
154 enabled, Emacs always highlights the region whenever there is a
157 @findex transient-mark-mode
158 To enable Transient Mark mode, type @kbd{M-x transient-mark-mode}.
159 This command toggles the mode; you can use the same command to turn
162 Here are the details of Transient Mark mode:
166 To set the mark, type @kbd{C-@key{SPC}} (@code{set-mark-command}).
167 This makes the mark active and thus begins highlighting of the region.
168 As you move point, you will see the highlighted region grow and
172 The mouse commands for specifying the mark also make it active. So do
173 keyboard commands whose purpose is to specify a region, including
174 @kbd{M-@@}, @kbd{C-M-@@}, @kbd{M-h}, @kbd{C-M-h}, @kbd{C-x C-p}, and
178 You can tell that the mark is active because the region is highlighted.
181 When the mark is active, you can execute commands that operate on the
182 region, such as killing, indenting, or writing to a file.
185 Any change to the buffer, such as inserting or deleting a character,
186 deactivates the mark. This means any subsequent command that operates
187 on a region will get an error and refuse to operate. You can make the
188 region active again by typing @kbd{C-x C-x}.
191 If Delete Selection mode is also enabled, some commands delete the
192 region when used while the mark is active. @xref{Graphical Kill}.
195 Quitting with @kbd{C-g} deactivates the mark.
198 Commands like @kbd{M->} and @kbd{C-s}, that ``leave the mark behind'' in
199 addition to some other primary purpose, do not activate the new mark.
200 You can activate the new region by executing @kbd{C-x C-x}
201 (@code{exchange-point-and-mark}).
204 Commands that normally set the mark before moving long distances (like
205 @kbd{M-<} and @kbd{C-s}) do not alter the mark in Transient Mark mode
206 when the mark is active.
209 Some commands operate on the region if a region is active. For
210 instance, @kbd{C-x u} in Transient Mark mode operates on the region,
211 when there is a region. (Outside Transient Mark mode, you must type
212 @kbd{C-u C-x u} if you want it to operate on the region.)
213 @xref{Undo}. Other commands that act this way are identified in their
217 The highlighting of the region uses the @code{region} face; you can
218 customize the appearance of the highlighted region by changing this
219 face. @xref{Face Customization}.
221 @vindex highlight-nonselected-windows
222 When multiple windows show the same buffer, they can have different
223 regions, because they can have different values of point (though they
224 all share one common mark position). Ordinarily, only the selected
225 window highlights its region (@pxref{Windows}). However, if the
226 variable @code{highlight-nonselected-windows} is non-@code{nil}, then
227 each window highlights its own region (provided that Transient Mark mode
228 is enabled and the mark in the window's buffer is active).
230 @vindex mark-even-if-inactive
231 If the variable @code{mark-even-if-inactive} is non-@code{nil} in
232 Transient Mark mode, then commands can use the mark and the region
233 even when it is inactive. Region highlighting appears and disappears
234 just as it normally does in Transient Mark mode, but the mark doesn't
235 really go away when the highlighting disappears, so you can still use
239 Transient Mark mode is also sometimes known as ``Zmacs mode''
240 because the Zmacs editor on the MIT Lisp Machine handled the mark in a
244 @section Using Transient Mark Mode Momentarily
246 If you don't like Transient Mark mode in general, you might still
247 want to use it once in a while. To do this, type @kbd{C-@key{SPC}
248 C-@key{SPC}} or @kbd{C-u C-x C-x}. These commands set or activate the
249 mark, and enable Transient Mark mode only until the mark is
253 @item C-@key{SPC} C-@key{SPC}
254 @kindex C-@key{SPC} C-@key{SPC}
255 Set the mark at point (like plain @kbd{C-@key{SPC}}), and enable
256 Transient Mark mode just once until the mark is deactivated. (This is
257 not really a separate command; you are using the @kbd{C-@key{SPC}}
262 Activate the mark without changing it; enable Transient Mark mode just
263 once, until the mark is deactivated. (This is the @kbd{C-x C-x}
264 command, @code{exchange-point-and-mark}, with a prefix argument.)
267 One of the secondary features of Transient Mark mode is that certain
268 commands operate only on the region, when there is an active region.
269 If you don't use Transient Mark mode, the region once set never
270 becomes inactive, so there is no way for these commands to make such a
271 distinction. Enabling Transient Mark mode momentarily gives you a way
272 to use these commands on the region.
274 Momentary use of Transient Mark mode is also a way to highlight the
275 region for the time being.
278 @section Operating on the Region
280 @cindex operations on a marked region
281 Once you have a region and the mark is active, here are some of the
282 ways you can operate on the region:
286 Kill it with @kbd{C-w} (@pxref{Killing}).
288 Save it in a register with @kbd{C-x r s} (@pxref{Registers}).
290 Save it in a buffer or a file (@pxref{Accumulating Text}).
292 Convert case with @kbd{C-x C-l} or @kbd{C-x C-u} (@pxref{Case}).
294 Indent it with @kbd{C-x @key{TAB}} or @kbd{C-M-\} (@pxref{Indentation}).
296 Fill it as text with @kbd{M-x fill-region} (@pxref{Filling}).
298 Print hardcopy with @kbd{M-x print-region} (@pxref{Printing}).
300 Evaluate it as Lisp code with @kbd{M-x eval-region} (@pxref{Lisp Eval}).
302 Undo changes within it using @kbd{C-u C-x u} (@pxref{Selective Undo}).
305 Most commands that operate on the text in the region have the word
306 @code{region} in their names.
309 @section Selective Undo
311 @cindex selective undo
313 Ordinary undo applies to all changes made in the current buffer. You
314 can also perform @dfn{selective undo}, limited to the current region
317 To do this, specify the region you want, then run the @code{undo}
318 command with a prefix argument (the value does not matter): @kbd{C-u
319 C-x u} or @kbd{C-u C-_}. This undoes the most recent change in the
320 region. To undo further changes in the same region, repeat the
321 @code{undo} command (no prefix argument is needed). In Transient Mark
322 mode (@pxref{Transient Mark}), any use of @code{undo} when there is an
323 active region performs selective undo; you do not need a prefix
326 @node Marking Objects
327 @section Commands to Mark Textual Objects
329 @cindex marking sections of text
330 Here are the commands for placing point and the mark around a textual
331 object such as a word, list, paragraph or page.
335 Set mark after end of next word (@code{mark-word}). This command and
336 the following one do not move point.
338 Set mark after end of following balanced expression (@code{mark-sexp}).
340 Put region around current paragraph (@code{mark-paragraph}).
342 Put region around current defun (@code{mark-defun}).
344 Put region around the entire buffer (@code{mark-whole-buffer}).
346 Put region around current page (@code{mark-page}).
349 @kbd{M-@@} (@code{mark-word}) puts the mark at the end of the next
350 word, while @kbd{C-M-@@} (@code{mark-sexp}) puts it at the end of the
351 next balanced expression (@pxref{Expressions}). These commands handle
352 arguments just like @kbd{M-f} and @kbd{C-M-f}. If you repeat these
353 commands, that extends the region. For example, you can type either
354 @kbd{C-u 2 M-@@} or @kbd{M-@@ M-@@} to mark the next two words. This
355 command also extends the region when the mark is active in Transient
356 Mark mode, regardless of the last command.
359 @findex mark-whole-buffer
360 Other commands set both point and mark, to delimit an object in the
361 buffer. For example, @kbd{M-h} (@code{mark-paragraph}) moves point to
362 the beginning of the paragraph that surrounds or follows point, and
363 puts the mark at the end of that paragraph (@pxref{Paragraphs}). It
364 prepares the region so you can indent, case-convert, or kill a whole
365 paragraph. With prefix argument, if the argument's value is positive,
366 @kbd{M-h} marks that many paragraphs starting with the one surrounding
367 point. If the prefix argument is @minus{}@var{n}, @kbd{M-h} also
368 marks @var{n} paragraphs, running back form the one surrounding point.
369 In that last case, point moves forward to the end of that paragraph,
370 and the mark goes at the start of the region. Repeating the @kbd{M-h}
371 command extends the region, just as with @kbd{M-@@} and @kbd{C-M-@@}.
373 @kbd{C-M-h} (@code{mark-defun}) similarly puts point before, and the
374 mark after, the current (or following) major top-level definition, or
375 defun (@pxref{Moving by Defuns}). Repeating @kbd{C-M-h} also extends
378 @kbd{C-x C-p} (@code{mark-page}) puts point before the current page,
379 and mark at the end (@pxref{Pages}). The mark goes after the
380 terminating page delimiter (to include it in the region), while point
381 goes after the preceding page delimiter (to exclude it). A numeric
382 argument specifies a later page (if positive) or an earlier page (if
383 negative) instead of the current page.
385 Finally, @kbd{C-x h} (@code{mark-whole-buffer}) sets up the entire
386 buffer as the region, by putting point at the beginning and the mark at
389 In Transient Mark mode, all of these commands activate the mark.
392 @section The Mark Ring
397 Aside from delimiting the region, the mark is also useful for
398 remembering a spot that you may want to go back to. To make this
399 feature more useful, each buffer remembers 16 previous locations of the
400 mark, in the @dfn{mark ring}. Commands that set the mark also push the
401 old mark onto this ring. To return to a marked location, use @kbd{C-u
402 C-@key{SPC}} (or @kbd{C-u C-@@}); this is the command
403 @code{set-mark-command} given a numeric argument. It moves point to
404 where the mark was, and restores the mark from the ring of former
407 @vindex set-mark-command-repeat-pop
408 If you set @code{set-mark-command-repeat-pop} to non-@code{nil},
409 then when you repeat the character @kbd{C-@key{SPC}} after typing
410 @kbd{C-u C-@key{SPC}}, each repetition moves point to a previous mark
411 position from the ring. The mark positions you move through in this
412 way are not lost; they go to the end of the ring.
414 Each buffer has its own mark ring. All editing commands use the current
415 buffer's mark ring. In particular, @kbd{C-u C-@key{SPC}} always stays in
418 Many commands that can move long distances, such as @kbd{M-<}
419 (@code{beginning-of-buffer}), start by setting the mark and saving the
420 old mark on the mark ring. This is to make it easier for you to move
421 back later. Searches set the mark if they move point. However, in
422 Transient Mark mode, these commands do not set the mark when the mark
423 is already active. You can tell when a command sets the mark because
424 it displays @samp{Mark set} in the echo area.
426 If you want to move back to the same place over and over, the mark
427 ring may not be convenient enough. If so, you can record the position
428 in a register for later retrieval (@pxref{RegPos,, Saving Positions in
431 @vindex mark-ring-max
432 The variable @code{mark-ring-max} specifies the maximum number of
433 entries to keep in the mark ring. If that many entries exist and
434 another one is pushed, the earliest one in the list is discarded. Repeating
435 @kbd{C-u C-@key{SPC}} cycles through the positions currently in the
439 The variable @code{mark-ring} holds the mark ring itself, as a list of
440 marker objects, with the most recent first. This variable is local in
443 @node Global Mark Ring
444 @section The Global Mark Ring
445 @cindex global mark ring
447 In addition to the ordinary mark ring that belongs to each buffer,
448 Emacs has a single @dfn{global mark ring}. It records a sequence of
449 buffers in which you have recently set the mark, so you can go back
452 Setting the mark always makes an entry on the current buffer's mark
453 ring. If you have switched buffers since the previous mark setting, the
454 new mark position makes an entry on the global mark ring also. The
455 result is that the global mark ring records a sequence of buffers that
456 you have been in, and, for each buffer, a place where you set the mark.
458 @kindex C-x C-@key{SPC}
459 @findex pop-global-mark
460 The command @kbd{C-x C-@key{SPC}} (@code{pop-global-mark}) jumps to
461 the buffer and position of the latest entry in the global ring. It also
462 rotates the ring, so that successive uses of @kbd{C-x C-@key{SPC}} take
463 you to earlier and earlier buffers.
466 arch-tag: f35e4d82-911b-4cfc-a3d7-3c87b2abba20