XEmacs 21.2.42 "Poseidon".

[chise/xemacs-chise.git.1] / info / xemacs-faq.info-2

This is ../info/xemacs-faq.info, produced by makeinfo version 4.0 from
xemacs-faq.texi.

INFO-DIR-SECTION XEmacs Editor
START-INFO-DIR-ENTRY
* FAQ: (xemacs-faq).            XEmacs FAQ.
END-INFO-DIR-ENTRY

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File: xemacs-faq.info,  Node: Q2.0.4,  Next: Q2.0.5,  Prev: Q2.0.3,  Up: Installation

Q2.0.4: Problems with Linux and ncurses.
----------------------------------------

   On Linux 1.3.98 with termcap 2.0.8 and the ncurses that came with
libc 5.2.18, XEmacs 20.0b20 is unable to open a tty device:

     src/xemacs -nw -q
     Initialization error:
     Terminal type `xterm' undefined (or can't access database?)

   Ben Wing <ben@xemacs.org> writes:

     Your ncurses configuration is messed up.  Your /usr/lib/terminfo
     is a bad pointer, perhaps to a CD-ROM that is not inserted.

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Q2.0.5: Do I need X11 to run XEmacs?
------------------------------------

   No.  The name "XEmacs" is unfortunate in the sense that it is *not*
an X Window System-only version of Emacs.  XEmacs has full color
support on a color-capable character terminal.

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Q2.0.6: I'm having strange crashes.  What do I do?
--------------------------------------------------

   There have been a variety of reports of crashes due to compilers with
buggy optimizers.  Please see the `PROBLEMS' file that comes with
XEmacs to read what it says about your platform.

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Q2.0.7: Libraries in non-standard locations
-------------------------------------------

   I have x-faces, jpeg, xpm etc. all in different places.  I've tried
space-separated, comma-separated, several -site-libraries, all to no
avail.

     --site-libraries='/path/one /path/two /path/etc'

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Q2.0.8: can't resolve symbol _h_errno
-------------------------------------

   You are using the Linux/ELF distribution of XEmacs 19.14, and your
ELF libraries are out of date.  You have the following options:

  1. Upgrade your libc to at least 5.2.16 (better is 5.2.18, 5.3.12, or
     5.4.10).

  2. Patch the XEmacs binary by replacing all occurrences of
     `_h_errno^@' with `h_errno^@^@'.  Any version of Emacs will
     suffice.  If you don't understand how to do this, don't do it.

  3. Rebuild XEmacs yourself--any working ELF version of libc should be
     O.K.

   Hrvoje Niksic <hniksic@xemacs.org> writes:

     Why not use a Perl one-liner for No. 2?

          perl -pi -e 's/_h_errno\0/h_errno\0\0/g' \
          /usr/local/bin/xemacs-19.14

     NB: You _must_ patch `/usr/local/bin/xemacs-19.14', and not
     `xemacs' because `xemacs' is a link to `xemacs-19.14'; the Perl
     `-i' option will cause unwanted side-effects if applied to a
     symbolic link.

   SL Baur <steve@xemacs.org> writes:

     If you build against a recent libc-5.4 (late enough to have caused
     problems earlier in the beta cycle) and then run with an earlier
     version of libc, you get a

          $ xemacs
          xemacs: can't resolve symbol '__malloc_hook'
          zsh: 7942 segmentation fault (core dumped)  xemacs

     (Example binary compiled against libc-5.4.23 and run with
     libc-5.4.16).

     The solution is to upgrade to at least libc-5.4.23.  Sigh.  Drat.

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Q2.0.9: Where do I find external libraries?
-------------------------------------------

   All external libraries used by XEmacs can be found at the XEmacs FTP
site `ftp://ftp.xemacs.org/pub/xemacs/aux/'.

   The canonical locations (at the time of this writing) are as follows:

JPEG
     `ftp://ftp.uu.net/graphics/jpeg/'.  Version 6a is current.

XPM
     `ftp://ftp.x.org/contrib/libraries/'.  Version 3.4j is current.
     Older versions of this package are known to cause XEmacs crashes.

TIFF
     `ftp://ftp.sgi.com/graphics/tiff/'.  v3.4 is current.  The latest
     beta is v3.4b035.  There is a HOWTO here.

PNG
     `ftp://ftp.uu.net/graphics/png/'.  0.89c is current.  XEmacs
     requires a fairly recent version to avoid using temporary files.

     `ftp://swrinde.nde.swri.edu/pub/png/src/'

Compface
     `ftp://ftp.cs.indiana.edu/pub/faces/compface/'.  This library has
     been frozen for about 6 years, and is distributed without version
     numbers.  _It should be compiled with the same options that X11 was
     compiled with on your system_.  The version of this library at
     XEmacs.org includes the `xbm2xface.pl' script, written by
     <stig@hackvan.com>, which may be useful when generating your own
     xface.

NAS
     `ftp://ftp.x.org/contrib/audio/nas/'.  Version 1.2p5 is current.
     There is a FAQ here.

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Q2.0.10: After I run configure I find a core dump, is something wrong?
----------------------------------------------------------------------

   Not necessarily.  If you have GNU sed 3.0 you should downgrade it to
2.05.  From the `README' at prep.ai.mit.edu:

     sed 3.0 has been withdrawn from distribution.  It has major
     revisions, which mostly seem to be improvements; but it turns out
     to have bugs too which cause trouble in some common cases.

     Tom Lord won't be able to work fixing the bugs until May.  So in
     the mean time, we've decided to withdraw sed 3.0 from distribution
     and make version 2.05 once again the recommended version.

   It has also been observed that the vfork test on Solaris will leave a
core dump.

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Q2.0.11: XEmacs doesn't resolve hostnames.
------------------------------------------

   This is the result of a long-standing problem with SunOS and the fact
that stock SunOS systems do not ship with DNS resolver code in libc.

   Christopher Davis <ckd@loiosh.kei.com> writes:

     That's correct [The SunOS 4.1.3 precompiled binaries don't do name
     lookup].  Since Sun figured that everyone used NIS to do name
     lookups (that DNS thing was apparently only a passing fad,
     right?), the stock SunOS 4.x systems don't have DNS-based name
     lookups in libc.

     This is also why Netscape ships two binaries for SunOS 4.1.x.

     The best solution is to compile it yourself; the configure script
     will check to see if you've put DNS in the shared libc and will
     then proceed to link against the DNS resolver library code.

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Q2.0.12: Why can't I strip XEmacs?
----------------------------------

   Richard Cognot <cognot@fronsac.ensg.u-nancy.fr> writes:

     Because of the way XEmacs (and every other Emacsen, AFAIK) is
     built. The link gives you a bare-boned emacs (called temacs).
     temacs is then run, preloading some of the lisp files. The result
     is then dumped into a new executable, named xemacs, which will
     contain all of the preloaded lisp functions and data.

     Now, during the dump itself, the executable (code+data+symbols) is
     written on disk using a special unexec() function. This function is
     obviously heavily system dependent. And on some systems, it leads
     to an executable which, although valid, cannot be stripped without
     damage. If memory serves, this is especially the case for AIX
     binaries. On other architecture it might work OK.

     The Right Way to strip the emacs binary is to strip temacs prior to
     dumping xemacs. This will always work, although you can do that
     only if you install from sources (as temacs is `not' part of the
     binary kits).

   Nat Makarevitch <nat@nataa.fr.eu.org> writes:

     Here is the trick:

       1. [ ./configure; make ]

       2. rm src/xemacs

       3. strip src/temacs

       4. make

       5. cp src/xemacs /usr/local/bin/xemacs

       6. cp lib-src/DOC-19.16-XEmacs
          /usr/local/lib/xemacs-19.16/i586-unknown-linuxaout

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Q2.0.13: I don't need no steenkin' packages.  Do I? (NEW)
---------------------------------------------------------

   Strictly speaking, no.  XEmacs will build and install just fine
without any packages installed.  However, only the most basic editing
functions will be available with no packages installed, so installing
packages is an essential part of making your installed XEmacs _useful_.

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Q2.0.12: How do I figure out which packages to install? (NEW)
-------------------------------------------------------------

   Many people really liked the old way that packages were bundled and
do not want to mess with packages at all.  You can grab all the
packages at once like you used to with old XEmacs versions.  Download
the file

   `xemacs-sumo.tar.gz'

   For an XEmacs compiled with Mule you also need

   `xemacs-mule-sumo.tar.gz'

   from the `packages' directory on your XEmacs mirror archive.  N.B.
They are called 'Sumo Tarballs' for good reason. They are currently
about 15MB and 2.3MB (gzipped) respectively.

   Install them by

   `cd $prefix/lib/xemacs ; gunzip -c <tarballname> | tar xf -'

   See README.packages for more detailed installation instructions.

   As the Sumo tarballs are not regenerated as often as the individual
packages, it is recommended that you use the automatic package tools
afterwards to pick up any recent updates.

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2.1: Trouble Shooting
=====================

Q2.1.1: Help!  XEmacs just crashed on me!
-----------------------------------------

   First of all, don't panic.  Whenever XEmacs crashes, it tries
extremely hard to auto-save all of your files before dying.  (The main
time that this will not happen is if the machine physically lost power
or if you killed the XEmacs process using `kill -9').  The next time
you try to edit those files, you will be informed that a more recent
auto-save file exists.  You can use `M-x recover-file' to retrieve the
auto-saved version of the file.

   Starting with 19.14, you may use the command `M-x recover-session'
after a crash to pick up where you left off.

   Now, XEmacs is not perfect, and there may occasionally be times, or
particular sequences of actions, that cause it to crash.  If you can
come up with a reproducible way of doing this (or even if you have a
pretty good memory of exactly what you were doing at the time), the
maintainers would be very interested in knowing about it.  Post a
message to comp.emacs.xemacs or send mail to <crashes@xemacs.org>.
Please note that the `crashes' address is exclusively for crash reports.

   If at all possible, include a stack backtrace of the core dump that
was produced.  This shows where exactly things went wrong, and makes it
much easier to diagnose problems.  To do this, you need to locate the
core file (it's called `core', and is usually sitting in the directory
that you started XEmacs from, or your home directory if that other
directory was not writable).  Then, go to that directory and execute a
command like:

     gdb `which xemacs` core

   and then issue the command `where' to get the stack backtrace.  You
might have to use `dbx' or some similar debugger in place of `gdb'.  If
you don't have any such debugger available, complain to your system
administrator.

   It's possible that a core file didn't get produced, in which case
you're out of luck.  Go complain to your system administrator and tell
him not to disable core files by default.  Also *Note Q2.1.15::, for
tips and techniques for dealing with a debugger.

   When making a problem report make sure that:

  1. Report *all* of the information output by XEmacs during the crash.

  2. You mention what O/S & Hardware you are running XEmacs on.

  3. What version of XEmacs you are running.

  4. What build options you are using.

  5. If the problem is related to graphics, we will also need to know
     what version of the X Window System you are running, and what
     window manager you are using.

  6. If the problem happened on a tty, please include the terminal type.

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Q2.1.2: Cryptic Minibuffer messages.
------------------------------------

   When I try to use some particular option of some particular package,
I get a cryptic error in the minibuffer.

   If you can't figure out what's going on, select Options/General
Options/Debug on Error from the Menubar and then try and make the error
happen again.  This will give you a backtrace that may be enlightening.
If not, try reading through this FAQ; if that fails, you could try
posting to comp.emacs.xemacs (making sure to include the backtrace) and
someone may be able to help.  If you can identify which Emacs lisp
source file the error is coming from you can get a more detailed stack
backtrace by doing the following:

  1. Visit the .el file in an XEmacs buffer.

  2. Issue the command `M-x eval-current-buffer'.

  3. Reproduce the error.

   Depending on the version of XEmacs, you may either select Edit->Show
Messages (19.13 and earlier) or Help->Recent Keystrokes/Messages (19.14
and later) from the menubar to see the most recent messages.  This
command is bound to `C-h l' by default.

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Q2.1.3: Translation Table Syntax messages at Startup
----------------------------------------------------

   I get tons of translation table syntax error messages during startup.
How do I get rid of them?

   There are two causes of this problem.  The first usually only strikes
people using the prebuilt binaries.  The culprit in both cases is the
file `XKeysymDB'.

   * The binary cannot find the `XKeysymDB' file.  The location is
     hardcoded at compile time so if the system the binary was built on
     puts it a different place than your system does, you have
     problems.  To fix, set the environment variable XKEYSYMDB to the
     location of the `XKeysymDB' file on your system or to the location
     of the one included with XEmacs which should be at
     `<xemacs_root_directory>/lib/xemacs-19.16/etc/XKeysymDB'.

   * The binary is finding the XKeysymDB but it is out-of-date on your
     system and does not contain the necessary lines.  Either ask your
     system administrator to replace it with the one which comes with
     XEmacs (which is the stock R6 version and is backwards compatible)
     or set your XKEYSYMDB variable to the location of XEmacs's
     described above.

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Q2.1.4: Startup warnings about deducing proper fonts?
-----------------------------------------------------

   How can I avoid the startup warnings about deducing proper fonts?

   This is highly dependent on your installation, but try with the
following font as your base font for XEmacs and see what it does:

-adobe-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-1

   More precisely, do the following in your resource file:

Emacs.default.attributeFont: \
-adobe-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-1

   If you just don't want to see the `*Warnings*' buffer at startup
time, you can set this:

     (setq display-warning-minimum-level 'error)

   The buffer still exists; it just isn't in your face.

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Q2.1.5: XEmacs cannot connect to my X Terminal!
-----------------------------------------------

   Help!  I can not get XEmacs to display on my Envizex X-terminal!

   Try setting the DISPLAY variable using the numeric IP address of the
host you are running XEmacs from.

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Q2.1.6: XEmacs just locked up my Linux X server!
------------------------------------------------

   There have been several reports of the X server locking up under
Linux.  In all reported cases removing speedo and scaled fonts from the
font path corrected the problem.  This can be done with the command
`xset'.

   It is possible that using a font server may also solve the problem.

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Q2.1.7: HP Alt key as Meta.
---------------------------

   How can I make XEmacs recognize the Alt key of my HP workstation as a
Meta key?

   Put the following line into a file and load it with xmodmap(1) before
starting XEmacs:

     remove Mod1 = Mode_switch

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Q2.1.8: got (wrong-type-argument color-instance-p nil)
------------------------------------------------------

   Natalie Kershaw <nataliek@rd.scitec.com.au> writes:

     I am trying to run xemacs 19.13 under X11R4. Whenever I move the
     mouse I get the following error. Has anyone seen anything like
     this? This doesn't occur on X11R5.

          Signalling:
          (error "got (wrong-type-argument color-instance-p nil)
          and I don't know why!")

   dinos <map01kd@gold.ac.uk> writes:

     I think this is due to undefined resources; You need to define
     color backgrounds and foregrounds into your
     `.../app-defaults/Emacs' like:

          *Foreground:    Black   ;everything will be of black on grey95,
          *Background:    Grey95  ;unless otherwise specified.
          *cursorColor:   Red3    ;red3 cursor with grey95 border.
          *pointerColor:  Red3    ;red3 pointer with grey95 border.

   Natalie Kershaw adds:

     What fixed the problem was adding some more colors to the X color
     database (copying the X11R5 colors over), and also defining the
     following resources:

          xemacs*cursorColor:    black
          xemacs*pointerColor:   black

     With the new colors installed the problem still occurs if the above
     resources are not defined.

     If the new colors are not present then an additional error occurs
     on XEmacs startup, which says `Color Red3' not defined.

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Q2.1.9: XEmacs causes my OpenWindows 3.0 server to crash.
---------------------------------------------------------

   The OpenWindows 3.0 server is incredibly buggy.  Your best bet is to
replace it with one from the generic MIT X11 release.  You might also
try disabling parts of your `.emacs', like enabling background pixmaps.

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Q2.1.10: Warnings from incorrect key modifiers.
-----------------------------------------------

   The following information comes from the `PROBLEMS' file that comes
with XEmacs.

   If you're having troubles with HP/UX it is because HP/UX defines the
modifiers wrong in X.  Here is a shell script to fix the problem; be
sure that it is run after VUE configures the X server.

     #! /bin/sh
     xmodmap 2> /dev/null - << EOF
     keysym Alt_L = Meta_L
     keysym Alt_R = Meta_R
     EOF
     
     xmodmap - << EOF
     clear mod1
     keysym Mode_switch = NoSymbol
     add mod1 = Meta_L
     keysym Meta_R = Mode_switch
     add mod2 = Mode_switch
     EOF

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Q2.1.11: `Can't instantiate image error...' in toolbar
------------------------------------------------------

   Dr. Ram Samudrala <expt@alanine.ram.org> writes:

   I just installed the XEmacs (20.4-2) RPMS that I downloaded from
`http://www.xemacs.org/'.  Everything works fine, except that when I
place my mouse over the toolbar, it beeps and gives me this message:

      Can't instantiate image (probably cached):
      [xbm :mask-file "/usr/include/X11/bitmaps/leftptrmsk :mask-data
      (16 16 <strange control characters> ...

   Kyle Jones <kyle_jones@wonderworks.com> writes:
     This is problem specific to some Chips and Technologies video
     chips, when running XFree86.  Putting

     `Option "sw_cursor"'

     in `XF86Config' gets rid of the problem.

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Q2.1.12: Problems with Regular Expressions on DEC OSF1.
-------------------------------------------------------

   I have xemacs 19.13 running on an alpha running OSF1 V3.2 148 and
ispell would not run because it claimed the version number was incorrect
although it was indeed OK. I traced the problem to the regular
expression handler.

   Douglas Kosovic <douglask@dstc.edu.au> writes:

     Actually it's a DEC cc optimization bug that screws up the regexp
     handling in XEmacs.

     Rebuilding using the `-migrate' switch for DEC cc (which uses a
     different sort of optimization) works fine.

   See `xemacs-19_13-dunix-3_2c.patch' at the following URL on how to
build with the `-migrate' flag:

     `http://www-digital.cern.ch/carney/emacs/emacs.html'

   NOTE: There have been a variety of other problems reported that are
fixed in this fashion.

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Q2.1.13: HP/UX 10.10 and `create_process' failure.
--------------------------------------------------

   Dave Carrigan <Dave.Carrigan@ipl.ca> writes:

     With XEmacs 19.13 and HP/UX 10.10, anything that relies on the
     `create_process' function fails. This breaks a lot of things
     (shell-mode, compile, ange-ftp, to name a few).

   Phil Johnson <johnson@dtc.hp.com> writes:

     This is a problem specific to HP-UX 10.10.  It only occurs when
     XEmacs is compiled for shared libraries (the default), so you can
     work around it by compiling a statically-linked binary (run
     configure with `--dynamic=no').

     I'm not sure whether the problem is with a particular shared
     library or if it's a kernel problem which crept into 10.10.

   Richard Cognot <cognot@ensg.u-nancy.fr> writes:

     I had a few problems with 10.10. Apparently, some of them were
     solved by forcing a static link of libc (manually).

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Q2.1.14: `C-g' doesn't work for me.  Is it broken?
--------------------------------------------------

   Ben Wing <ben@xemacs.org> writes:

     `C-g' does work for most people in most circumstances.  If it
     doesn't, there are only two explanations:

       1. The code is wrapped with a binding of `inhibit-quit' to `t'.
          `Ctrl-Shift-G' should still work, I think.

       2. SIGIO is broken on your system, but BROKEN_SIGIO isn't
          defined.

     To test #2, try executing `(while t)' from the `*scratch*' buffer.
     If `C-g' doesn't interrupt, then you're seeing #2.

   Morten Welinder <terra@diku.dk> writes:

     On some (but _not_ all) machines a hung XEmacs can be revived by
     `kill -FPE <pid>'.  This is a hack, of course, not a solution.
     This technique works on a Sun4 running 4.1.3_U1.  To see if it
     works for you, start another XEmacs and test with that first.  If
     you get a core dump the method doesn't work and if you get
     `Arithmetic error' then it does.

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Q2.1.15: How to Debug an XEmacs problem with a debugger
-------------------------------------------------------

   If XEmacs does crash on you, one of the most productive things you
can do to help get the bug fixed is to poke around a bit with the
debugger.  Here are some hints:

   * First of all, if the crash is at all reproducible, consider very
     strongly recompiling your XEmacs with debugging symbols, with no
     optimization, and with the configure options `--debug=yes' and
     `--error-checking=all'.  This will make your XEmacs run somewhat
     slower but make it a lot more likely to catch the problem earlier
     (closer to its source), and a lot easier to determine what's going
     on with a debugger.

   * If you're able to run XEmacs under a debugger and reproduce the
     crash (if it's inconvenient to do this because XEmacs is already
     running or is running in batch mode as part of a bunch of scripts,
     consider attaching to the existing process with your debugger;
     most debuggers let you do this by substituting the process ID for
     the core file when you invoke the debugger from the command line,
     or by using the `attach' command or something similar), here are
     some things you can do:

   * If XEmacs is hitting an assertion failure, put a breakpoint on
     `assert_failed()'.

   * If XEmacs is hitting some weird Lisp error that's causing it to
     crash (e.g. during startup), put a breakpoint on
     `signal_1()'--this is declared static in eval.c.

   * Internally, you will probably see lots of variables that hold
     objects of type `Lisp_Object'.  These are exactly what they appear
     to be, i.e. references to Lisp objects.  Printing them out with
     the debugger probably won't be too useful--you'll likely just see
     a number.  To decode them, do this:

          call debug_print (OBJECT)

     where OBJECT is whatever you want to decode (it can be a variable,
     a function call, etc.).  This will print out a readable
     representation on the TTY from which the xemacs process was
     invoked.

   * If you want to get a Lisp backtrace showing the Lisp call stack,
     do this:

          call debug_backtrace ()

   * Using `debug_print' and `debug_backtrace' has two disadvantages -
     it can only be used with a running xemacs process, and it cannot
     display the internal C structure of a Lisp Object.  Even if all
     you've got is a core dump, all is not lost.

     If you're using GDB, there are some macros in the file
     `src/.gdbinit' in the XEmacs source distribution that should make
     it easier for you to decode Lisp objects.  This file is
     automatically read by gdb if gdb is run in the directory where
     xemacs was built, and contains these useful macros to inspect the
     state of xemacs:

    `pobj'
          Usage: pobj lisp_object
          Print the internal C representation of a lisp object.

    `xtype'
          Usage: xtype lisp_object
          Print the Lisp type of a lisp object.

    `lbt'
          Usage: lbt
          Print the current Lisp stack trace.  Requires a running
          xemacs process.

    `ldp'
          Usage: ldp lisp_object
          Print a Lisp Object value using the Lisp printer.  Requires a
          running xemacs process.

    `run-temacs'
          Usage: run-temacs
          Run temacs interactively, like xemacs.  Use this with
          debugging tools (like purify) that cannot deal with dumping,
          or when temacs builds successfully, but xemacs does not.

    `dump-temacs'
          Usage: dump-temacs
          Run the dumping part of the build procedure.  Use when
          debugging temacs, not xemacs!  Use this when temacs builds
          successfully, but xemacs does not.

    `check-xemacs'
          Usage: check-xemacs
          Run the test suite.  Equivalent to 'make check'.

    `check-temacs'
          Usage: check-temacs
          Run the test suite on temacs.  Equivalent to 'make
          check-temacs'.  Use this with debugging tools (like purify)
          that cannot deal with dumping, or when temacs builds
          successfully, but xemacs does not.

     If you are using Sun's `dbx' debugger, there is an equivalent file
     `src/.dbxrc', which defines the same commands for dbx.

   * If you're using a debugger to get a C stack backtrace and you're
     seeing stack traces with some of the innermost frames mangled, it
     may be due to dynamic linking. (This happens especially under
     Linux.) Consider reconfiguring with `--dynamic=no'.  Also,
     sometimes (again under Linux), stack backtraces of core dumps will
     have the frame where the fatal signal occurred mangled; if you can
     obtain a stack trace while running the XEmacs process under a
     debugger, the stack trace should be clean.

     Curtiss <1CMC3466@ibm.mtsac.edu> suggests upgrading to ld.so
     version 1.8 if dynamic linking and debugging is a problem on Linux.

   * If you're using a debugger to get a C stack backtrace and you're
     getting a completely mangled and bogus stack trace, it's probably
     due to one of the following:

       a. Your executable has been stripped.  Bad news.  Tell your
          sysadmin not to do this--it doesn't accomplish anything
          except to save a bit of disk space, and makes debugging much
          much harder.

       b. Your stack is getting trashed.  Debugging this is hard; you
          have to do a binary-search type of narrowing down where the
          crash occurs, until you figure out exactly which line is
          causing the problem.  Of course, this only works if the bug
          is highly reproducible.

       c. If your stack trace has exactly one frame in it, with address
          0x0, this could simply mean that XEmacs attempted to execute
          code at that address, e.g. through jumping to a null function
          pointer.  Unfortunately, under those circumstances, GDB under
          Linux doesn't know how to get a stack trace. (Yes, this is
          the third Linux-related problem I've mentioned.  I have no
          idea why GDB under Linux is so bogus.  Complain to the GDB
          authors, or to comp.os.linux.development.system).  Again,
          you'll have to use the narrowing-down process described above.

       d. If you compiled 19.14 with `--debug' (or by default in later
          versions), you will get a Lisp backtrace output when XEmacs
          crashes, so you'll have something useful.


   * If you compile with the newer gcc variants gcc-2.8 or egcs, you
     will also need gdb 4.17 or above.  Earlier releases of gdb can't
     handle the debug information generated by the newer compilers.

   * In versions of XEmacs before 21.2.27, `src/.gdbinit' was named
     `src/gdbinit'.  This had the disadvantage of not being sourced
     automatically by gdb, so you had to set that up yourself.


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File: xemacs-faq.info,  Node: Q2.1.16,  Next: Q2.1.17,  Prev: Q2.1.15,  Up: Installation

Q2.1.16: XEmacs crashes in `strcat' on HP/UX 10
-----------------------------------------------

   From the problems database (through the former address
http://support.mayfield.hp.com/):

     Problem Report: 5003302299
     Status:         Open
     
     System/Model:   9000/700
     Product Name:   HPUX S800 10.0X
     Product Vers:   9245XB.10.00
     
     Description: strcat(3C) may read beyond
     end of source string, can cause SIGSEGV
     
     
     *** PROBLEM TEXT ***
     strcat(3C) may read beyond the source string onto an unmapped page,
     causing a segmentation violation.

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File: xemacs-faq.info,  Node: Q2.1.17,  Next: Q2.1.18,  Prev: Q2.1.16,  Up: Installation

Q2.1.17: `Marker does not point anywhere'
-----------------------------------------

   As with other errors, set `debug-on-error' to `t' to get the
backtrace when the error occurs.  Specifically, two problems have been
reported (and fixed).

  1. A problem with line-number-mode in XEmacs 19.14 affected a large
     number of other packages.  If you see this error message, turn off
     line-number-mode.

  2. A problem with some early versions of Gnus 5.4 caused this error.
     Upgrade your Gnus.

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Q2.1.18: removed
----------------

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File: xemacs-faq.info,  Node: Q2.1.19,  Next: Q2.1.20,  Prev: Q2.1.18,  Up: Installation

Q2.1.19: XEmacs does not follow the local timezone.
---------------------------------------------------

   When using one of the prebuilt binaries many users have observed that
XEmacs uses the timezone under which it was built, but not the timezone
under which it is running.  The solution is to add:

     (set-time-zone-rule "MET")

   to your `.emacs' or the `site-start.el' file if you can.  Replace
`MET' with your local timezone.

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File: xemacs-faq.info,  Node: Q2.1.20,  Next: Q2.1.21,  Prev: Q2.1.19,  Up: Installation

Q2.1.20: `Symbol's function definition is void: hkey-help-show.'
----------------------------------------------------------------

   This is a problem with a partially loaded hyperbole.  Try adding:

     (require 'hmouse-drv)

   where you load hyperbole and the problem should go away.

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Q2.1.21: [This question intentionally left blank]
-------------------------------------------------

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Q2.1.22: XEmacs seems to take a really long time to do some things
------------------------------------------------------------------

   David Moore <dmoore@ucsd.edu> writes:

     Two things you can do:

     1) C level:

     When you see it going mad like this, you might want to use gdb
     from an 'xterm' to attach to the running process and get a stack
     trace.  To do this just run:

          gdb /path/to/xemacs/xemacs ####

     Where `####' is the process id of your xemacs, instead of
     specifying the core.  When gdb attaches, the xemacs will stop [1]
     and you can type `where' in gdb to get a stack trace as usual.  To
     get things moving again, you can just type `quit' in gdb.  It'll
     tell you the program is running and ask if you want to quit
     anyways.  Say 'y' and it'll quit and have your emacs continue from
     where it was at.

     2) Lisp level:

     Turn on debug-on-quit early on.  When you think things are going
     slow hit C-g and it may pop you in the debugger so you can see
     what routine is running.  Press `c' to get going again.

     debug-on-quit doesn't work if something's turned on inhibit-quit
     or in some other strange cases.

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File: xemacs-faq.info,  Node: Q2.1.23,  Next: Q2.1.24,  Prev: Q2.1.22,  Up: Installation

Q2.1.23:  Movemail on Linux does not work for XEmacs 19.15 and later.
---------------------------------------------------------------------

   Movemail used to work fine in 19.14 but has stopped working in 19.15
and 20.x.  I am using Linux.

   SL Baur <steve@xemacs.org> writes:

     Movemail on Linux used to default to using flock file locking.
     With 19.15 and later versions it now defaults to using `.lock' file
     locking.  If this is not appropriate for your system, edit
     src/s/linux.h and uncomment the line that reads:

          #define MAIL_USE_FLOCK

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File: xemacs-faq.info,  Node: Q2.1.24,  Next: Q2.1.25,  Prev: Q2.1.23,  Up: Installation

Q2.1.24:  XEmacs won't start without network. (NEW)
---------------------------------------------------

   If XEmacs starts when you're on the network, but fails when you're
not on the network, you may be missing a "localhost" entry in your
`/etc/hosts' file.  The file should contain an entry like:

     127.0.0.1        localhost

   Add that line, and XEmacs will be happy.

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File: xemacs-faq.info,  Node: Q2.1.25,  Prev: Q2.1.24,  Up: Installation

Q2.1.25::  After upgrading, XEmacs won't do `foo' any more! (NEW)
-----------------------------------------------------------------

   You have been used to doing `foo', but now when you invoke it (or
click the toolbar button or select the menu item), nothing (or an error)
happens.  The simplest explanation is that you are missing a package
that is essential to you.  You can either track it down and install it
(there is a list of packages and brief descriptions of their contents in
`etc/PACKAGES'), or install the `Sumo Tarball' (see *note Q2.0.14::).

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File: xemacs-faq.info,  Node: Customization,  Next: Subsystems,  Prev: Installation,  Up: Top

3 Customization and Options
***************************

   This is part 3 of the XEmacs Frequently Asked Questions list.  This
section is devoted to Customization and screen settings.

* Menu:

Customization---Emacs Lisp and `.emacs':
* Q3.0.1::      What version of Emacs am I running?
* Q3.0.2::      How do I evaluate Elisp expressions?
* Q3.0.3::      `(setq tab-width 6)' behaves oddly.
* Q3.0.4::      How can I add directories to the `load-path'?
* Q3.0.5::      How to check if a lisp function is defined?
* Q3.0.6::      Can I force the output of `(face-list)' to a buffer?
* Q3.0.7::      Font selections don't get saved after `Save Options'.
* Q3.0.8::      How do I make a single minibuffer frame?
* Q3.0.9::      What is `Customize'?

X Window System & Resources:
* Q3.1.1::      Where is a list of X resources?
* Q3.1.2::      How can I detect a color display?
* Q3.1.3::      [This question intentionally left blank]
* Q3.1.4::      [This question intentionally left blank]
* Q3.1.5::      How can I get the icon to just say `XEmacs'?
* Q3.1.6::      How can I have the window title area display the full path?
* Q3.1.7::      `xemacs -name junk' doesn't work?
* Q3.1.8::      `-iconic' doesn't work.

Textual Fonts & Colors:
* Q3.2.1::      How can I set color options from `.emacs'?
* Q3.2.2::      How do I set the text, menu and modeline fonts?
* Q3.2.3::      How can I set the colors when highlighting a region?
* Q3.2.4::      How can I limit color map usage?
* Q3.2.5::      My tty supports color, but XEmacs doesn't use them.
* Q3.2.6::      Can I have pixmap backgrounds in XEmacs?

The Modeline:
* Q3.3.1::      How can I make the modeline go away?
* Q3.3.2::      How do you have XEmacs display the line number in the modeline?
* Q3.3.3::      How do I get XEmacs to put the time of day on the modeline?
* Q3.3.4::      How do I turn off current chapter from AUC TeX modeline?
* Q3.3.5::      How can one change the modeline color based on the mode used?

3.4 Multiple Device Support:
* Q3.4.1::      How do I open a frame on another screen of my multi-headed display?
* Q3.4.2::      Can I really connect to a running XEmacs after calling up over a modem?  How?

3.5 The Keyboard:
* Q3.5.1::      How can I bind complex functions (or macros) to keys?
* Q3.5.2::      How can I stop down-arrow from adding empty lines to the bottom of my buffers?
* Q3.5.3::      How do I bind C-. and C-; to scroll one line up and down?
* Q3.5.4::      Globally binding Delete?
* Q3.5.5::      Scrolling one line at a time.
* Q3.5.6::      How to map Help key alone on Sun type4 keyboard?
* Q3.5.7::      How can you type in special characters in XEmacs?
* Q3.5.8::      Why does `(global-set-key [delete-forward] 'delete-char)' complain?
* Q3.5.9::      How do I make the Delete key delete forward?
* Q3.5.10::     Can I turn on "sticky" modifier keys?
* Q3.5.11::     How do I map the arrow keys?

The Cursor:
* Q3.6.1::      Is there a way to make the bar cursor thicker?
* Q3.6.2::      Is there a way to get back the old block cursor where the cursor covers the character in front of the point?
* Q3.6.3::      Can I make the cursor blink?

The Mouse and Highlighting:
* Q3.7.1::      How can I turn off Mouse pasting?
* Q3.7.2::      How do I set control/meta/etc modifiers on mouse buttons?
* Q3.7.3::      Clicking the left button does not do anything in buffer list.
* Q3.7.4::      How can I get a list of buffers when I hit mouse button 3?
* Q3.7.5::      Why does cut-and-paste not work between XEmacs and a cmdtool?
* Q3.7.6::      How I can set XEmacs up so that it pastes where the text cursor is?
* Q3.7.7::      How do I select a rectangular region?
* Q3.7.8::      Why does M-w take so long?

The Menubar and Toolbar:
* Q3.8.1::      How do I get rid of the menu (or menubar)?
* Q3.8.2::      Can I customize the basic menubar?
* Q3.8.3::      How do I control how many buffers are listed in the menu `Buffers' list?
* Q3.8.4::      Resources like `Emacs*menubar*font' are not working?
* Q3.8.5::      How can I bind a key to a function to toggle the toolbar?

Scrollbars:
* Q3.9.1::      How can I disable the scrollbar?
* Q3.9.2::      How can one use resources to change scrollbar colors?
* Q3.9.3::      Moving the scrollbar can move the point; can I disable this?
* Q3.9.4::      How can I get automatic horizontal scrolling?

Text Selections:
* Q3.10.1::     How can I turn off or change highlighted selections?
* Q3.10.2::     How do I get that typing on an active region removes it?
* Q3.10.3::     Can I turn off the highlight during isearch?
* Q3.10.4::     How do I turn off highlighting after C-x C-p (mark-page)?
* Q3.10.5::     The region disappears when I hit the end of buffer while scrolling.

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File: xemacs-faq.info,  Node: Q3.0.1,  Next: Q3.0.2,  Prev: Customization,  Up: Customization

3.0: Customization - Emacs Lisp and .emacs
==========================================

Q3.0.1: What version of Emacs am I running?
-------------------------------------------

   How can `.emacs' determine which of the family of Emacsen I am using?

   To determine if you are currently running GNU Emacs 18, GNU Emacs 19,
XEmacs 19, XEmacs 20, or Epoch, and use appropriate code, check out the
example given in `etc/sample.emacs'.  There are other nifty things in
there as well!

   For all new code, all you really need to do is:

     (defvar running-xemacs (string-match "XEmacs\\|Lucid" emacs-version))

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File: xemacs-faq.info,  Node: Q3.0.2,  Next: Q3.0.3,  Prev: Q3.0.1,  Up: Customization

Q3.0.2: How can I evaluate Emacs-Lisp expressions?
--------------------------------------------------

   I know I can evaluate Elisp expressions from `*scratch*' buffer with
`C-j' after the expression.  How do I do it from another buffer?

   Press `M-:' (the default binding of `eval-expression'), and enter
the expression to the minibuffer.  In XEmacs prior to 19.15
`eval-expression' used to be a disabled command by default.  If this is
the case, upgrade your XEmacs.

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File: xemacs-faq.info,  Node: Q3.0.3,  Next: Q3.0.4,  Prev: Q3.0.2,  Up: Customization

Q3.0.3: `(setq tab-width 6)' behaves oddly.
-------------------------------------------

   If you put `(setq tab-width 6)' in your `.emacs' file it does not
work!  Is there a reason for this?  If you do it at the EVAL prompt it
works fine!! How strange.

   Use `setq-default' instead, since `tab-width' is all-buffer-local.

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File: xemacs-faq.info,  Node: Q3.0.4,  Next: Q3.0.5,  Prev: Q3.0.3,  Up: Customization

Q3.0.4: How can I add directories to the `load-path'?
-----------------------------------------------------

   Here are two ways to do that, one that puts your directories at the
front of the load-path, the other at the end:

     ;;; Add things at the beginning of the load-path, do not add
     ;;; duplicate directories:
     (pushnew "bar" load-path :test 'equal)
     
     (pushnew "foo" load-path :test 'equal)
     
     ;;; Add things at the end, unconditionally
     (setq load-path (nconc load-path '("foo" "bar")))

   keith (k.p.) hanlan <keithh@nortel.ca> writes:

     To add directories using Unix shell metacharacters use
     `expand-file-name' like this:

          (push (expand-file-name "~keithh/.emacsdir") load-path)

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File: xemacs-faq.info,  Node: Q3.0.5,  Next: Q3.0.6,  Prev: Q3.0.4,  Up: Customization

Q3.0.5: How to check if a lisp function is defined?
---------------------------------------------------

   Use the following elisp:

     (fboundp 'foo)

   It's almost always a mistake to test `emacs-version' or any similar
variables.

   Instead, use feature-tests, such as `featurep', `boundp', `fboundp',
or even simple behavioral tests, eg.:

     (defvar foo-old-losing-code-p
       (condition-case nil (progn (losing-code t) nil)
         (wrong-number-of-arguments t)))

   There is an incredible amount of broken code out there which could
work much better more often in more places if it did the above instead
of trying to divine its environment from the value of one variable.

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File: xemacs-faq.info,  Node: Q3.0.6,  Next: Q3.0.7,  Prev: Q3.0.5,  Up: Customization

Q3.0.6: Can I force the output of `(face-list)' to a buffer?
------------------------------------------------------------

   It would be good having it in a buffer, as the output of
`(face-list)' is too wide to fit to a minibuffer.

   Evaluate the expression in the `*scratch*' buffer with point after
the rightmost paren and typing `C-j'.

   If the minibuffer smallness is the only problem you encounter, you
can simply press `C-h l' to get the former minibuffer contents in a
buffer.

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Q3.0.7: Font selections in don't get saved after `Save Options'.
----------------------------------------------------------------

   For XEmacs 19.14 and previous:

   John Mann <mannj@ll.mit.edu> writes:

     You have to go to Options->Frame Appearance and unselect
     `Frame-Local Font Menu'.  If this option is selected, font changes
     are only applied to the _current_ frame and do _not_ get saved
     when you save options.

   For XEmacs 19.15 and later:

   Implement the above as well as set the following in your `.emacs'

     (setq options-save-faces t)

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File: xemacs-faq.info,  Node: Q3.0.8,  Next: Q3.0.9,  Prev: Q3.0.7,  Up: Customization

Q3.0.8: How do I get a single minibuffer frame?
-----------------------------------------------

   Vin Shelton <acs@acm.org> writes:

     (setq initial-frame-plist '(minibuffer nil))
     (setq default-frame-plist '(minibuffer nil))
     (setq default-minibuffer-frame
           (make-frame
            '(minibuffer only
                         width 86
                         height 1
                         menubar-visible-p nil
                         default-toolbar-visible-p nil
                         name "minibuffer"
                         top -2
                         left -2
                         has-modeline-p nil)))
     (frame-notice-user-settings)

   *Please note:* The single minibuffer frame may not be to everyone's
taste, and there any number of other XEmacs options settings that may
make it difficult or inconvenient to use.

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File: xemacs-faq.info,  Node: Q3.0.9,  Next: Q3.1.1,  Prev: Q3.0.8,  Up: Customization

Q3.0.9: What is `Customize'?
----------------------------

   Starting with XEmacs 20.2 there is new system 'Customize' for
customizing XEmacs options.

   You can access `Customize' from the `Options' menu or invoking one
of customize commands by typing eg.  `M-x customize', `M-x
customize-face', `M-x customize-variable' or `M-x customize-apropos'.

   Starting with XEmacs 20.3 there is also new `browser' mode for
Customize.  Try it out with `M-x customize-browse'

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File: xemacs-faq.info,  Node: Q3.1.1,  Next: Q3.1.2,  Prev: Q3.0.9,  Up: Customization

3.1: X Window System & Resources
================================

Q3.1.1: Where is a list of X resources?
---------------------------------------

   Search through the `NEWS' file for `X Resources'.  A fairly
comprehensive list is given after it.

   In addition, an `app-defaults' file is supplied, `etc/Emacs.ad'
listing the defaults.  The file `etc/sample.Xdefaults' gives a set of
defaults that you might consider.  It is essentially the same as
`etc/Emacs.ad' but some entries are slightly altered.  Be careful about
installing the contents of this file into your `.Xdefaults' or
`.Xresources' file if you use GNU Emacs under X11 as well.

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Q3.1.2: How can I detect a color display?
-----------------------------------------

   You can test the return value of the function `(device-class)', as
in:

     (when (eq (device-class) 'color)
       (set-face-foreground  'font-lock-comment-face "Grey")
       (set-face-foreground  'font-lock-string-face  "Red")
       ....
       )

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Q3.1.3: [This question intentionally left blank]
------------------------------------------------

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Q3.1.4: [This question intentionally left blank]
------------------------------------------------

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Q3.1.5: How can I get the icon to just say `XEmacs'?
----------------------------------------------------

   I'd like the icon to just say `XEmacs', and not include the name of
the current file in it.

   Add the following line to your `.emacs':

     (setq frame-icon-title-format "XEmacs")

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File: xemacs-faq.info,  Node: Q3.1.6,  Next: Q3.1.7,  Prev: Q3.1.5,  Up: Customization

Q3.1.6: How can I have the window title area display the full path?
-------------------------------------------------------------------

   I'd like to have the window title area display the full
directory/name of the current buffer file and not just the name.

   Add the following line to your `.emacs':

     (setq frame-title-format "%S: %f")

   A more sophisticated title might be:

     (setq frame-title-format
           '("%S: " (buffer-file-name "%f"
                                      (dired-directory dired-directory "%b"))))

   That is, use the file name, or the dired-directory, or the buffer
name.