annotate man/xemacs/undo.texi @ 2367:ecf1ebac70d8

[xemacs-hg @ 2004-11-04 23:05:23 by ben] commit mega-patch configure.in: Turn off -Winline and -Wchar-subscripts. Use the right set of cflags when compiling modules. Rewrite ldap configuration to separate the inclusion of lber (needed in recent Cygwin) from the basic checks for the needed libraries. add a function for MAKE_JUNK_C; initially code was added to generate xemacs.def using this, but it will need to be rewritten. add an rm -f for junk.c to avoid weird Cygwin bug with cp -f onto an existing file. Sort list of auto-detected functions and eliminate unused checks for stpcpy, setlocale and getwd. Add autodetection of Cygwin scanf problems BETA: Rewrite section on configure to indicate what flags are important and what not. digest-doc.c, make-dump-id.c, profile.c, sorted-doc.c: Add proper decls for main(). make-msgfile.c: Document that this is old junk. Move proposal to text.c. make-msgfile.lex: Move proposal to text.c. make-mswin-unicode.pl: Convert error-generating code so that the entire message will be seen as a single unrecognized token. mule/mule-ccl.el: Update docs. lispref/mule.texi: Update CCL docs. ldap/eldap.c: Mule-ize. Use EXTERNAL_LIST_LOOP_2 instead of deleted EXTERNAL_LIST_LOOP. * XEmacs 21.5.18 "chestnut" is released. --------------------------------------------------------------- MULE-RELATED WORK: --------------------------------------------------------------- --------------------------- byte-char conversion --------------------------- buffer.c, buffer.h, insdel.c, text.c: Port FSF algorithm for byte-char conversion, replacing broken previous version. Track the char position of the gap. Add functions to do char-byte conversion downwards as well as upwards. Move comments about algorithm workings to internals manual. --------------------------- work on types --------------------------- alloc.c, console-x-impl.h, dump-data.c, dump-data.h, dumper.c, dialog-msw.c, dired-msw.c, doc.c, editfns.c, esd.c, event-gtk.h, event-msw.c, events.c, file-coding.c, file-coding.h, fns.c, glyphs-eimage.c, glyphs-gtk.c, glyphs-msw.c, glyphs-shared.c, glyphs-x.c, glyphs.c, glyphs.h, gui.c, hpplay.c, imgproc.c, intl-win32.c, lrecord.h, lstream.c, keymap.c, lisp.h, libsst.c, linuxplay.c, miscplay.c, miscplay.h, mule-coding.c, nas.c, nt.c, ntheap.c, ntplay.c, objects-msw.c, objects-tty.c, objects-x.c, print.c, process-nt.c, process.c, redisplay.h, select-common.h, select-gtk.c, select-x.c, sgiplay.c, sound.c, sound.h, sunplay.c, sysfile.h, sysdep.c, syswindows.h, text.c, unexnt.c, win32.c, xgccache.c: Further work on types. This creates a full set of types for all the basic semantics of `char' that I have so far identified, so that its semantics can always be identified for the purposes of proper Mule-safe code, and the raw use of `char' always avoided. (1) More type renaming, for consistency of naming. Char_ASCII -> Ascbyte UChar_ASCII -> UAscbyte Char_Binary -> CBinbyte UChar_Binary -> Binbyte SChar_Binary -> SBinbyte (2) Introduce Rawbyte, CRawbyte, Boolbyte, Chbyte, UChbyte, and Bitbyte and use them. (3) New types Itext, Wexttext and Textcount for separating out the concepts of bytes and textual units (different under UTF-16 and UTF-32, which are potential internal encodings). (4) qxestr*_c -> qxestr*_ascii. lisp.h: New; goes with other qxe() functions. #### Maybe goes in a different section. lisp.h: Group generic int-type defs together with EMACS_INT defs. lisp.h: * lisp.h (WEXTTEXT_IS_WIDE) New defns. lisp.h: New type to replace places where int occurs as a boolean. It's signed because occasionally people may want to use -1 as an error value, and because unsigned ints are viral -- see comments in the internals manual against using them. dynarr.c: int -> Bytecount. --------------------------- Mule-izing --------------------------- device-x.c: Partially Mule-ize. dumper.c, dumper.h: Mule-ize. Use Rawbyte. Use stderr_out not printf. Use wext_*(). sysdep.c, syswindows.h, text.c: New Wexttext API for manipulation of external text that may be Unicode (e.g. startup code under Windows). emacs.c: Mule-ize. Properly deal with argv in external encoding. Use wext_*() and Wexttext. Use Rawbyte. #if 0 some old junk on SCO that is unlikely to be correct. Rewrite allocation code in run-temacs. emacs.c, symsinit.h, win32.c: Rename win32 init function and call it even earlier, to initialize mswindows_9x_p even earlier, for use in startup code (XEUNICODE_P). process.c: Use _wenviron not environ under Windows, to get Unicode environment variables. event-Xt.c: Mule-ize drag-n-drop related stuff. dragdrop.c, dragdrop.h, frame-x.c: Mule-ize. text.h: Add some more stand-in defines for particular kinds of conversion; use in Mule-ization work in frame-x.c etc. --------------------------- Freshening --------------------------- intl-auto-encap-win32.c, intl-auto-encap-win32.h: Regenerate. --------------------------- Unicode-work --------------------------- intl-win32.c, syswindows.h: Factor out common options to MultiByteToWideChar and WideCharToMultiByte. Add convert_unicode_to_multibyte_malloc() and convert_unicode_to_multibyte_dynarr() and use. Add stuff for alloca() conversion of multibyte/unicode. alloc.c: Use dfc_external_data_len() in case of unicode coding system. alloc.c, mule-charset.c: Don't zero out and reinit charset Unicode tables. This fucks up dump-time loading. Anyway, either we load them at dump time or run time, never both. unicode.c: Dump the blank tables as well. --------------------------------------------------------------- DOCUMENTATION, MOSTLY MULE-RELATED: --------------------------------------------------------------- EmacsFrame.c, emodules.c, event-Xt.c, fileio.c, input-method-xlib.c, mule-wnnfns.c, redisplay-gtk.c, redisplay-tty.c, redisplay-x.c, regex.c, sysdep.c: Add comment about Mule work needed. text.h: Add more documentation describing why DFC routines were not written to return their value. Add some other DFC documentation. console-msw.c, console-msw.h: Add pointer to docs in win32.c. emacs.c: Add comments on sources of doc info. text.c, charset.h, unicode.c, intl-win32.c, intl-encap-win32.c, text.h, file-coding.c, mule-coding.c: Collect background comments and related to text matters and internationalization, and proposals for work to be done, in text.c or Internals manual, stuff related to specific textual API's in text.h, and stuff related to internal implementation of Unicode conversion in unicode.c. Put lots of pointers to the comments to make them easier to find. s/mingw32.h, s/win32-common.h, s/win32-native.h, s/windowsnt.h, win32.c: Add bunches of new documentation on the different kinds of builds and environments under Windows and how they work. Collect this info in win32.c. Add pointers to these docs in the relevant s/* files. emacs.c: Document places with long comments. Remove comment about exiting, move to internals manual, put in pointer. event-stream.c: Move docs about event queues and focus to internals manual, put in pointer. events.h: Move docs about event stream callbacks to internals manual, put in pointer. profile.c, redisplay.c, signal.c: Move documentation to the Internals manual. process-nt.c: Add pointer to comment in win32-native.el. lisp.h: Add comments about some comment conventions. lisp.h: Add comment about the second argument. device-msw.c, redisplay-msw.c: @@#### comments are out-of-date. --------------------------------------------------------------- PDUMP WORK (MOTIVATED BY UNICODE CHANGES) --------------------------------------------------------------- alloc.c, buffer.c, bytecode.c, console-impl.h, console.c, device.c, dumper.c, lrecord.h, elhash.c, emodules.h, events.c, extents.c, frame.c, glyphs.c, glyphs.h, mule-charset.c, mule-coding.c, objects.c, profile.c, rangetab.c, redisplay.c, specifier.c, specifier.h, window.c, lstream.c, file-coding.h, file-coding.c: PDUMP: Properly implement dump_add_root_block(), which never worked before, and is necessary for dumping Unicode tables. Pdump name changes for accuracy: XD_STRUCT_PTR -> XD_BLOCK_PTR. XD_STRUCT_ARRAY -> XD_BLOCK_ARRAY. XD_C_STRING -> XD_ASCII_STRING. *_structure_* -> *_block_*. lrecord.h: some comments added about dump_add_root_block() vs dump_add_root_block_ptr(). extents.c: remove incorrect comment about pdump problems with gap array. --------------------------------------------------------------- ALLOCATION --------------------------------------------------------------- abbrev.c, alloc.c, bytecode.c, casefiddle.c, device-msw.c, device-x.c, dired-msw.c, doc.c, doprnt.c, dragdrop.c, editfns.c, emodules.c, file-coding.c, fileio.c, filelock.c, fns.c, glyphs-eimage.c, glyphs-gtk.c, glyphs-msw.c, glyphs-x.c, gui-msw.c, gui-x.c, imgproc.c, intl-win32.c, lread.c, menubar-gtk.c, menubar.c, nt.c, objects-msw.c, objects-x.c, print.c, process-nt.c, process-unix.c, process.c, realpath.c, redisplay.c, search.c, select-common.c, symbols.c, sysdep.c, syswindows.h, text.c, text.h, ui-byhand.c: New macros {alloca,xnew}_{itext,{i,ext,raw,bin,asc}bytes} for more convenient allocation of these commonly requested items. Modify functions to use alloca_ibytes, alloca_array, alloca_extbytes, xnew_ibytes, etc. also XREALLOC_ARRAY, xnew. alloc.c: Rewrite the allocation functions to factor out repeated code. Add assertions for freeing dumped data. lisp.h: Moved down and consolidated with other allocation stuff. lisp.h, dynarr.c: New functions for allocation that's very efficient when mostly in LIFO order. lisp.h, text.c, text.h: Factor out some stuff for general use by alloca()-conversion funs. text.h, lisp.h: Fill out convenience routines for allocating various kinds of bytes and put them in lisp.h. Use them in place of xmalloc(), ALLOCA(). text.h: Fill out the convenience functions so the _MALLOC() kinds match the alloca() kinds. --------------------------------------------------------------- ERROR-CHECKING --------------------------------------------------------------- text.h: Create ASSERT_ASCTEXT_ASCII() and ASSERT_ASCTEXT_ASCII_LEN() from similar Eistring checkers and change the Eistring checkers to use them instead. --------------------------------------------------------------- MACROS IN LISP.H --------------------------------------------------------------- lisp.h: Redo GCPRO declarations. Create a "base" set of functions that can be used to generate any kind of gcpro sets -- regular, ngcpro, nngcpro, private ones used in GC_EXTERNAL_LIST_LOOP_2. buffer.c, callint.c, chartab.c, console-msw.c, device-x.c, dialog-msw.c, dired.c, extents.c, ui-gtk.c, rangetab.c, nt.c, mule-coding.c, minibuf.c, menubar-msw.c, menubar.c, menubar-gtk.c, lread.c, lisp.h, gutter.c, glyphs.c, glyphs-widget.c, fns.c, fileio.c, file-coding.c, specifier.c: Eliminate EXTERNAL_LIST_LOOP, which does not check for circularities. Use EXTERNAL_LIST_LOOP_2 instead or EXTERNAL_LIST_LOOP_3 or EXTERNAL_PROPERTY_LIST_LOOP_3 or GC_EXTERNAL_LIST_LOOP_2 (new macro). Removed/redid comments on EXTERNAL_LIST_LOOP. --------------------------------------------------------------- SPACING FIXES --------------------------------------------------------------- callint.c, hftctl.c, number-gmp.c, process-unix.c: Spacing fixes. --------------------------------------------------------------- FIX FOR GEOMETRY PROBLEM IN FIRST FRAME --------------------------------------------------------------- unicode.c: Add workaround for newlib bug in sscanf() [should be fixed by release 1.5.12 of Cygwin]. toolbar.c: bug fix for problem of initial frame being 77 chars wide on Windows. will be overridden by my other ws. --------------------------------------------------------------- FIX FOR LEAKING PROCESS HANDLES: --------------------------------------------------------------- process-nt.c: Fixes for leaking handles. Inspired by work done by Adrian Aichner <adrian@xemacs.org>. --------------------------------------------------------------- FIX FOR CYGWIN BUG (Unicode-related): --------------------------------------------------------------- unicode.c: Add workaround for newlib bug in sscanf() [should be fixed by release 1.5.12 of Cygwin]. --------------------------------------------------------------- WARNING FIXES: --------------------------------------------------------------- console-stream.c: `reinit' is unused. compiler.h, event-msw.c, frame-msw.c, intl-encap-win32.c, text.h: Add stuff to deal with ANSI-aliasing warnings I got. regex.c: Gather includes together to avoid warning. --------------------------------------------------------------- CHANGES TO INITIALIZATION ROUTINES: --------------------------------------------------------------- buffer.c, emacs.c, console.c, debug.c, device-x.c, device.c, dragdrop.c, emodules.c, eval.c, event-Xt.c, event-gtk.c, event-msw.c, event-stream.c, event-tty.c, events.c, extents.c, faces.c, file-coding.c, fileio.c, font-lock.c, frame-msw.c, glyphs-widget.c, glyphs.c, gui-x.c, insdel.c, lread.c, lstream.c, menubar-gtk.c, menubar-x.c, minibuf.c, mule-wnnfns.c, objects-msw.c, objects.c, print.c, scrollbar-x.c, search.c, select-x.c, text.c, undo.c, unicode.c, window.c, symsinit.h: Call reinit_*() functions directly from emacs.c, for clarity. Factor out some redundant init code. Move disallowed stuff that had crept into vars_of_glyphs() into complex_vars_of_glyphs(). Call init_eval_semi_early() from eval.c not in the middle of vars_of_() in emacs.c since there should be no order dependency in the latter calls. --------------------------------------------------------------- ARMAGEDDON: --------------------------------------------------------------- alloc.c, emacs.c, lisp.h, print.c: Rename inhibit_non_essential_printing_operations to inhibit_non_essential_conversion_operations. text.c: Assert on !inhibit_non_essential_conversion_operations. console-msw.c, print.c: Don't do conversion in SetConsoleTitle or FindWindow to avoid problems during armageddon. Put #errors for NON_ASCII_INTERNAL_FORMAT in places where problems would arise. --------------------------------------------------------------- CHANGES TO THE BUILD PROCEDURE: --------------------------------------------------------------- config.h.in, s/cxux.h, s/usg5-4-2.h, m/powerpc.h: Add comment about correct ordering of this file. Rearrange everything to follow this -- put all #undefs together and before the s&m files. Add undefs for HAVE_ALLOCA, C_ALLOCA, BROKEN_ALLOCA_IN_FUNCTION_CALLS, STACK_DIRECTION. Remove unused HAVE_STPCPY, HAVE_GETWD, HAVE_SETLOCALE. m/gec63.h: Deleted; totally broken, not used at all, not in FSF. m/7300.h, m/acorn.h, m/alliant-2800.h, m/alliant.h, m/altos.h, m/amdahl.h, m/apollo.h, m/att3b.h, m/aviion.h, m/celerity.h, m/clipper.h, m/cnvrgnt.h, m/convex.h, m/cydra5.h, m/delta.h, m/delta88k.h, m/dpx2.h, m/elxsi.h, m/ews4800r.h, m/gould.h, m/hp300bsd.h, m/hp800.h, m/hp9000s300.h, m/i860.h, m/ibmps2-aix.h, m/ibmrs6000.h, m/ibmrt-aix.h, m/ibmrt.h, m/intel386.h, m/iris4d.h, m/iris5d.h, m/iris6d.h, m/irist.h, m/isi-ov.h, m/luna88k.h, m/m68k.h, m/masscomp.h, m/mg1.h, m/mips-nec.h, m/mips-siemens.h, m/mips.h, m/news.h, m/nh3000.h, m/nh4000.h, m/ns32000.h, m/orion105.h, m/pfa50.h, m/plexus.h, m/pmax.h, m/powerpc.h, m/pyrmips.h, m/sequent-ptx.h, m/sequent.h, m/sgi-challenge.h, m/symmetry.h, m/tad68k.h, m/tahoe.h, m/targon31.h, m/tekxd88.h, m/template.h, m/tower32.h, m/tower32v3.h, m/ustation.h, m/vax.h, m/wicat.h, m/xps100.h: Delete C_ALLOCA, HAVE_ALLOCA, STACK_DIRECTION, BROKEN_ALLOCA_IN_FUNCTION_CALLS. All of this is auto-detected. When in doubt, I followed recent FSF sources, which also have these things deleted.
author ben
date Thu, 04 Nov 2004 23:08:28 +0000
parents 376386a54a3c
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
0
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
1
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
2 @node Undo, Minibuffer, Basic, Top
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
3 @chapter Undoing Changes
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
4 @cindex undo
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
5 @cindex mistakes, correcting
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
6
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
7 Emacs allows you to undo all changes you make to the text of a buffer,
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
8 up to a certain amount of change (8000 characters). Each buffer records
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
9 changes individually, and the undo command always applies to the
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
10 current buffer. Usually each editing command makes a separate entry
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
11 in the undo records, but some commands such as @code{query-replace}
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
12 make many entries, and very simple commands such as self-inserting
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
13 characters are often grouped to make undoing less tedious.
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
14
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
15 @table @kbd
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
16 @item C-x u
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
17 Undo one batch of changes (usually, one command's worth) (@code{undo}).
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
18 @item C-_
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
19 The same.
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
20 @end table
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
21
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
22 @kindex C-x u
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
23 @kindex C-_
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
24 @findex undo
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
25 The command @kbd{C-x u} or @kbd{C-_} allows you to undo changes. The
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
26 first time you give this command, it undoes the last change. Point
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
27 moves to the text affected by the undo, so you can see what was undone.
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
28
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
29 Consecutive repetitions of the @kbd{C-_} or @kbd{C-x u} commands undo
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
30 earlier and earlier changes, back to the limit of what has been
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
31 recorded. If all recorded changes have already been undone, the undo
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
32 command prints an error message and does nothing.
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
33
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
34 Any command other than an undo command breaks the sequence of undo
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
35 commands. Starting at this moment, the previous undo commands are
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
36 considered ordinary changes that can themselves be undone. Thus, you can
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
37 redo changes you have undone by typing @kbd{C-f} or any other command
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
38 that have no important effect, and then using more undo commands.
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
39
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
40 If you notice that a buffer has been modified accidentally, the
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
41 easiest way to recover is to type @kbd{C-_} repeatedly until the stars
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
42 disappear from the front of the mode line. When that happens, all the
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
43 modifications you made have been canceled. If you do not remember
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
44 whether you changed the buffer deliberately, type @kbd{C-_} once. When
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
45 you see Emacs undo the last change you made, you probably remember why you
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
46 made it. If the change was an accident, leave it undone. If it was
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
47 deliberate, redo the change as described in the preceding paragraph.
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
48
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
49 Whenever an undo command makes the stars disappear from the mode line,
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
50 the buffer contents is the same as it was when the file was last read in
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
51 or saved.
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
52
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
53 Not all buffers record undo information. Buffers whose names start with
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
54 spaces don't; these buffers are used internally by Emacs and its extensions
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
55 to hold text that users don't normally look at or edit. Minibuffers,
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
56 help buffers, and documentation buffers also don't record undo information.
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
57
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
58 Emacs can remember at most 8000 or so characters of deleted or
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
59 modified text in any one buffer for reinsertion by the undo command.
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
60 There is also a limit on the number of individual insert, delete, or
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
61 change actions that Emacs can remember.
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
62
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
63 There are two keys to run the @code{undo} command, @kbd{C-x u} and
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
64 @kbd{C-_}, because on some keyboards, it is not obvious how to type
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
65 @kbd{C-_}. @kbd{C-x u} is an alternative you can type in the same
376386a54a3c Import from CVS: tag r19-14
cvs
parents:
diff changeset
66 fashion on any terminal.