This is Info file ../../info/xemacs.info, produced by Makeinfo-1.63
from the input file xemacs.texi.

   This file documents the XEmacs editor.

   Copyright (C) 1985, 1986, 1988 Richard M. Stallman.  Copyright (C)
1991, 1992, 1993, 1994 Lucid, Inc.  Copyright (C) 1993, 1994 Sun
Microsystems, Inc.  Copyright (C) 1995 Amdahl Corporation.

   Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.

   Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the sections entitled "The GNU Manifesto", "Distribution" and "GNU
General Public License" are included exactly as in the original, and
provided that the entire resulting derived work is distributed under the
terms of a permission notice identical to this one.

   Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the sections entitled "The GNU Manifesto",
"Distribution" and "GNU General Public License" may be included in a
translation approved by the author instead of in the original English.


File: xemacs.info,  Node: Quitting,  Next: Lossage,  Prev: Customization,  Up: Top

Quitting and Aborting
=====================

`C-g'
     Quit.  Cancel running or partially typed command.

`C-]'
     Abort innermost recursive editing level and cancel the command
     which invoked it (`abort-recursive-edit').

`M-x top-level'
     Abort all recursive editing levels that are currently executing.

`C-x u'
     Cancel an already-executed command, usually (`undo').

   There are two ways of cancelling commands which are not finished
executing: "quitting" with `C-g', and "aborting" with `C-]' or `M-x
top-level'.  Quitting is cancelling a partially typed command or one
which is already running.  Aborting is getting out of a recursive
editing level and cancelling the command that invoked the recursive
edit.

   Quitting with `C-g' is used for getting rid of a partially typed
command or a numeric argument that you don't want.  It also stops a
running command in the middle in a relatively safe way, so you can use
it if you accidentally start executing a command that takes a long
time.  In particular, it is safe to quit out of killing; either your
text will ALL still be there, or it will ALL be in the kill ring (or
maybe both).  Quitting an incremental search does special things
documented under searching; in general, it may take two successive
`C-g' characters to get out of a search.  `C-g' works by setting the
variable `quit-flag' to `t' the instant `C-g' is typed; Emacs Lisp
checks this variable frequently and quits if it is non-`nil'.  `C-g' is
only actually executed as a command if it is typed while Emacs is
waiting for input.

   If you quit twice in a row before the first `C-g' is recognized, you
activate the "emergency escape" feature and return to the shell.  *Note
Emergency Escape::.

   You can use `C-]' (`abort-recursive-edit') to get out of a recursive
editing level and cancel the command which invoked it.  Quitting with
`C-g' does not do this, and could not do this because it is used to
cancel a partially typed command within the recursive editing level.
Both operations are useful.  For example, if you are in the Emacs
debugger (*note Lisp Debug::.) and have typed `C-u 8' to enter a
numeric argument, you can cancel that argument with `C-g' and remain in
the debugger.

   The command `M-x top-level' is equivalent to "enough" `C-]' commands
to get you out of all the levels of recursive edits that you are in.
`C-]' only gets you out one level at a time, but `M-x top-level' goes
out all levels at once.  Both `C-]' and `M-x top-level' are like all
other commands and unlike `C-g' in that they are effective only when
Emacs is ready for a command.  `C-]' is an ordinary key and has its
meaning only because of its binding in the keymap.  *Note Recursive
Edit::.

   `C-x u' (`undo') is not strictly speaking a way of cancelling a
command, but you can think of it as cancelling a command already
finished executing.  *Note Undo::.


File: xemacs.info,  Node: Lossage,  Next: Bugs,  Prev: Quitting,  Up: Top

Dealing With Emacs Trouble
==========================

   This section describes various conditions in which Emacs fails to
work, and how to recognize them and correct them.

* Menu:

* Stuck Recursive::    `[...]' in mode line around the parentheses.
* Screen Garbled::     Garbage on the screen.
* Text Garbled::       Garbage in the text.
* Unasked-for Search:: Spontaneous entry to incremental search.
* Emergency Escape::   Emergency escape--
                        What to do if Emacs stops responding.
* Total Frustration::  When you are at your wits' end.


File: xemacs.info,  Node: Stuck Recursive,  Next: Screen Garbled,  Prev: Lossage,  Up: Lossage

Recursive Editing Levels
------------------------

   Recursive editing levels are important and useful features of Emacs,
but they can seem like malfunctions to the user who does not understand
them.

   If the mode line has square brackets `[...]' around the parentheses
that contain the names of the major and minor modes, you have entered a
recursive editing level.  If you did not do this on purpose, or if you
don't understand what that means, you should just get out of the
recursive editing level.  To do so, type `M-x top-level'.  This is
called getting back to top level.  *Note Recursive Edit::.


File: xemacs.info,  Node: Screen Garbled,  Next: Text Garbled,  Prev: Stuck Recursive,  Up: Lossage

Garbage on the Screen
---------------------

   If the data on the screen looks wrong, the first thing to do is see
whether the text is actually wrong.  Type `C-l', to redisplay the
entire screen.  If the text appears correct after this, the problem was
entirely in the previous screen update.

   Display updating problems often result from an incorrect termcap
entry for the terminal you are using.  The file `etc/TERMS' in the Emacs
distribution gives the fixes for known problems of this sort.
`INSTALL' contains general advice for these problems in one of its
sections.  Very likely there is simply insufficient padding for certain
display operations.  To investigate the possibility that you have this
sort of problem, try Emacs on another terminal made by a different
manufacturer.  If problems happen frequently on one kind of terminal but
not another kind, the real problem is likely to be a bad termcap entry,
though it could also be due to a bug in Emacs that appears for terminals
that have or lack specific features.


File: xemacs.info,  Node: Text Garbled,  Next: Unasked-for Search,  Prev: Screen Garbled,  Up: Lossage

Garbage in the Text
-------------------

   If `C-l' shows that the text is wrong, try undoing the changes to it
using `C-x u' until it gets back to a state you consider correct.  Also
try `C-h l' to find out what command you typed to produce the observed
results.

   If a large portion of text appears to be missing at the beginning or
end of the buffer, check for the word `Narrow' in the mode line.  If it
appears, the text is still present, but marked off-limits.  To make it
visible again, type `C-x n w'.  *Note Narrowing::.


File: xemacs.info,  Node: Unasked-for Search,  Next: Emergency Escape,  Prev: Text Garbled,  Up: Lossage

Spontaneous Entry to Incremental Search
---------------------------------------

   If Emacs spontaneously displays `I-search:' at the bottom of the
screen, it means that the terminal is sending `C-s' and `C-q' according
to the poorly designed xon/xoff "flow control" protocol.  You should
try to prevent this by putting the terminal in a mode where it will not
use flow control, or by giving it enough padding that it will never
send a `C-s'.  If that cannot be done, you must tell Emacs to expect
flow control to be used, until you can get a properly designed terminal.

   Information on how to do these things can be found in the file
`INSTALL' in the Emacs distribution.


File: xemacs.info,  Node: Emergency Escape,  Next: Total Frustration,  Prev: Unasked-for Search,  Up: Lossage

Emergency Escape
----------------

   Because at times there have been bugs causing Emacs to loop without
checking `quit-flag', a special feature causes Emacs to be suspended
immediately if you type a second `C-g' while the flag is already set,
so you can always get out of XEmacs.  Normally Emacs recognizes and
clears `quit-flag' (and quits!) quickly enough to prevent this from
happening.

   When you resume Emacs after a suspension caused by multiple `C-g', it
asks two questions before going back to what it had been doing:

     Auto-save? (y or n)
     Abort (and dump core)? (y or n)

Answer each one with `y' or `n' followed by RET.

   Saying `y' to `Auto-save?' causes immediate auto-saving of all
modified buffers in which auto-saving is enabled.

   Saying `y' to `Abort (and dump core)?' causes an illegal instruction
to be executed, dumping core.  This is to enable a wizard to figure out
why Emacs was failing to quit in the first place.  Execution does not
continue after a core dump.  If you answer `n', execution does
continue.  With luck, Emacs will ultimately check `quit-flag' and quit
normally.  If not, and you type another `C-g', it is suspended again.

   If Emacs is not really hung, but is just being slow, you may invoke
the double `C-g' feature without really meaning to.  In that case,
simply resume and answer `n' to both questions, and you will arrive at
your former state.  Presumably the quit you requested will happen soon.

   The double-`C-g' feature may be turned off when Emacs is running
under a window system, since the window system always enables you to
kill Emacs or to create another window and run another program.


File: xemacs.info,  Node: Total Frustration,  Prev: Emergency Escape,  Up: Lossage

Help for Total Frustration
--------------------------

   If using Emacs (or something else) becomes terribly frustrating and
none of the techniques described above solve the problem, Emacs can
still help you.

   First, if the Emacs you are using is not responding to commands, type
`C-g C-g' to get out of it and then start a new one.

   Second, type `M-x doctor RET'.

   The doctor will make you feel better.  Each time you say something to
the doctor, you must end it by typing RET RET.  This lets the doctor
know you are finished.


File: xemacs.info,  Node: Bugs,  Prev: Lossage,  Up: Top

Reporting Bugs
==============

   Sometimes you will encounter a bug in Emacs.  Although we cannot
promise we can or will fix the bug, and we might not even agree that it
is a bug, we want to hear about bugs you encounter in case we do want
to fix them.

   To make it possible for us to fix a bug, you must report it.  In
order to do so effectively, you must know when and how to do it.

When Is There a Bug
-------------------

   If Emacs executes an illegal instruction, or dies with an operating
system error message that indicates a problem in the program (as
opposed to something like "disk full"), then it is certainly a bug.

   If Emacs updates the display in a way that does not correspond to
what is in the buffer, then it is certainly a bug.  If a command seems
to do the wrong thing but the problem corrects itself if you type
`C-l', it is a case of incorrect display updating.

   Taking forever to complete a command can be a bug, but you must make
certain that it was really Emacs's fault.  Some commands simply take a
long time.  Type `C-g' and then `C-h l' to see whether the input Emacs
received was what you intended to type; if the input was such that you
KNOW it should have been processed quickly, report a bug.  If you don't
know whether the command should take a long time, find out by looking
in the manual or by asking for assistance.

   If a command you are familiar with causes an Emacs error message in a
case where its usual definition ought to be reasonable, it is probably a
bug.

   If a command does the wrong thing, that is a bug.  But be sure you
know for certain what it ought to have done.  If you aren't familiar
with the command, or don't know for certain how the command is supposed
to work, then it might actually be working right.  Rather than jumping
to conclusions, show the problem to someone who knows for certain.

   Finally, a command's intended definition may not be best for editing
with.  This is a very important sort of problem, but it is also a
matter of judgment.  Also, it is easy to come to such a conclusion out
of ignorance of some of the existing features.  It is probably best not
to complain about such a problem until you have checked the
documentation in the usual ways, feel confident that you understand it,
and know for certain that what you want is not available.  If you are
not sure what the command is supposed to do after a careful reading of
the manual, check the index and glossary for any terms that may be
unclear.  If you still do not understand, this indicates a bug in the
manual.  The manual's job is to make everything clear.  It is just as
important to report documentation bugs as program bugs.

   If the online documentation string of a function or variable
disagrees with the manual, one of them must be wrong, so report the bug.

How to Report a Bug
-------------------

   When you decide that there is a bug, it is important to report it
and to report it in a way which is useful.  What is most useful is an
exact description of what commands you type, starting with the shell
command to run Emacs, until the problem happens.  Always include the
version number of Emacs that you are using; type `M-x emacs-version' to
print this.

   The most important principle in reporting a bug is to report FACTS,
not hypotheses or categorizations.  It is always easier to report the
facts, but people seem to prefer to strain to posit explanations and
report them instead.  If the explanations are based on guesses about
how Emacs is implemented, they will be useless; we will have to try to
figure out what the facts must have been to lead to such speculations.
Sometimes this is impossible.  But in any case, it is unnecessary work
for us.

   For example, suppose that you type `C-x C-f /glorp/baz.ugh RET',
visiting a file which (you know) happens to be rather large, and Emacs
prints out `I feel pretty today'.  The best way to report the bug is
with a sentence like the preceding one, because it gives all the facts
and nothing but the facts.

   Do not assume that the problem is due to the size of the file and
say, "When I visit a large file, Emacs prints out `I feel pretty
today'." This is what we mean by "guessing explanations".  The problem
is just as likely to be due to the fact that there is a `z' in the file
name.  If this is so, then when we got your report, we would try out
the problem with some "large file", probably with no `z' in its name,
and not find anything wrong.  There is no way in the world that we
could guess that we should try visiting a file with a `z' in its name.

   Alternatively, the problem might be due to the fact that the file
starts with exactly 25 spaces.  For this reason, you should make sure
that you inform us of the exact contents of any file that is needed to
reproduce the bug.  What if the problem only occurs when you have typed
the `C-x a l' command previously?  This is why we ask you to give the
exact sequence of characters you typed since starting to use Emacs.

   You should not even say "visit a file" instead of `C-x C-f' unless
you know that it makes no difference which visiting command is used.
Similarly, rather than saying "if I have three characters on the line,"
say "after I type `RET A B C RET C-p'," if that is the way you entered
the text.

   If you are not in Fundamental mode when the problem occurs, you
should say what mode you are in.

   If the manifestation of the bug is an Emacs error message, it is
important to report not just the text of the error message but a
backtrace showing how the Lisp program in Emacs arrived at the error.
To make the backtrace, you must execute the Lisp expression `(setq
debug-on-error t)' before the error happens (that is to say, you must
execute that expression and then make the bug happen).  This causes the
Lisp debugger to run (*note Lisp Debug::.).  The debugger's backtrace
can be copied as text into the bug report.  This use of the debugger is
possible only if you know how to make the bug happen again.  Do note
the error message the first time the bug happens, so if you can't make
it happen again, you can report at least that.

   Check whether any programs you have loaded into the Lisp world,
including your `.emacs' file, set any variables that may affect the
functioning of Emacs.  Also, see whether the problem happens in a
freshly started Emacs without loading your `.emacs' file (start Emacs
with the `-q' switch to prevent loading the init file).  If the problem
does NOT occur then, it is essential that we know the contents of any
programs that you must load into the Lisp world in order to cause the
problem to occur.

   If the problem does depend on an init file or other Lisp programs
that are not part of the standard Emacs system, then you should make
sure it is not a bug in those programs by complaining to their
maintainers first.  After they verify that they are using Emacs in a
way that is supposed to work, they should report the bug.

   If you can tell us a way to cause the problem without visiting any
files, please do so.  This makes it much easier to debug.  If you do
need files, make sure you arrange for us to see their exact contents.
For example, it can often matter whether there are spaces at the ends
of lines, or a newline after the last line in the buffer (nothing ought
to care whether the last line is terminated, but tell that to the bugs).

   The easy way to record the input to Emacs precisely is to write a
dribble file; execute the Lisp expression:

     (open-dribble-file "~/dribble")

using `Meta-ESC' or from the `*scratch*' buffer just after starting
Emacs.  From then on, all Emacs input will be written in the specified
dribble file until the Emacs process is killed.

   For possible display bugs, it is important to report the terminal
type (the value of environment variable `TERM'), the complete termcap
entry for the terminal from `/etc/termcap' (since that file is not
identical on all machines), and the output that Emacs actually sent to
the terminal.  The way to collect this output is to execute the Lisp
expression:

     (open-termscript "~/termscript")

using `Meta-ESC' or from the `*scratch*' buffer just after starting
Emacs.  From then on, all output from Emacs to the terminal will be
written in the specified termscript file as well, until the Emacs
process is killed.  If the problem happens when Emacs starts up, put
this expression into your `.emacs' file so that the termscript file will
be open when Emacs displays the screen for the first time.  Be warned:
it is often difficult, and sometimes impossible, to fix a
terminal-dependent bug without access to a terminal of the type that
stimulates the bug.

   The newsgroup `comp.emacs.xemacs' may be used for bug reports, other
discussions and requests for assistance.

   If you don't have access to this newgroup, you can subscribe to the
mailing list version: the newsgroup is bidirectionally gatewayed into
the mailing list `xemacs@xemacs.org'.

   To be added or removed from this mailing list, send mail to
`xemacs-request@xemacs.org'.  Do not send requests for addition to the
mailing list itself.

   The mailing lists and newsgroups are archived on our anonymous FTP
server, `ftp.xemacs.org', and at various other archive sites around the
net. You should also check the `FAQ' in `/pub/xemacs' on our anonymous
FTP server. It provides some introductory information and help for
initial configuration problems.

