InfoMagic Source Code 1993 July/THE_SOURCE_CODE_CD_ROM.iso/X/mit/doc/tutorials/FAQ.censored

Internet Message Format | 1991-07-21 | 114.0 KB

Subject: Frequently Asked Questions about X with Answers [long monthly posting]

[Last changed: 30 Jun 91]
[For distribution with R5, parts of this document relating to older
problems or containing commercial announcements have been removed.]

This article contains the answers to some Frequently Asked Questions (FAQ)
often seen in comp.windows.x. It is posted to help reduce volume in this
newsgroup and to provide hard-to-find information of general interest.

        Please redistribute this article!

This article includes answers to the following questions, which are loosely
grouped into categories. Questions marked with a + indicate questions new to
this issue; those with significant changes of content since the last issue are
marked by *:

  0)  TOPIC: BASIC INFORMATION SOURCES AND DEFINITIONS
  1)  What books and articles on X are good for beginners?
  2)  [Removed]
  3)  [Removed]
  4)  What X-related public mailing lists are available?
  5)  How do I ask a net-question so as to maximize helpful responses?
  6)  What publications discussing X are available?
  7)  How can I meet other X developers? (What is XUG? AFUX? EXUG?)
  8)  What are these common abbreviations?
  9)  What is the ICCCM? (How do I write X-friendly applications?)
 10)  What is the X Consortium, and how do I join?
 11)  Just what are OPEN LOOK and Motif?
 12)  [Removed]
 13)  [Removed]
 14)  What is PEX?
 15)  TOPIC: USING X IN DAY-TO-DAY LIFE
 16)  What are all these different window managers?
 17)  Why does my X session exit when I kill my window manager?
 18)  Is there a way for my WM to produce my .xinitrc, like toolplaces?
 19)  How do I use another window manager with DEC's session manager?
 20)  How do I change the keyboard auto-repeat rate?
 21)  How do I remap the keys on my keyboard to produce a string?
 22)  How do I make a screendump of the X display?
 23)  How do I make a color PostScript screendump of the X display?
 24)  How can I print the current selection?
 25)  Why are my xterm menus so small?
 26)  Where can I find a dictionary server for xwebster?
 27)  How do I convert/view Mac/TIFF/GIF/Sun/PICT/img/FAX images in X?
 28)  How can I change the titlebar of my xterm window?
 29)  Where can I find the xterm control sequences? [edited]
 30)  How do I keep my $DISPLAY when I rlogin to another machine?
 31)  How can I design my own font?
 32)  Why does adding a font to the server not work?
 33)  How do I convert a ".snf" font back to ".bdf" font?
 34)  What is a general method of getting a font in usable format?
 35)  How do I use HP ".scf" fonts on my MIT R4 server?
 36)  How do I use DECwindows ".pcf" fonts on my MIT R4 server?
 37)  How do I use DECwindows fonts on my non-DECwindows server?
 38)  How do I add ".bdf" fonts to my DECwindows server?
 39)  Why can't I set the backgroundPixmap resource in a defaults file?
 40)  Why does the R3 xterm, et al, fail against the R4 server?
 41)  [Removed]
 42)  How can I have xclock or oclock show different timezones?
 43)  I have xmh, but it doesn't work. Where can I get mh?
 44)  Why am I suddenly unable to connect to my Sun X server?
 45)  Why can't I override translations? Only the first item works.
 46)  How do I report bugs in X?
 47)  TOPIC: OBTAINING X AND RELATED SOFTWARE AND HARDWARE
 48)  Is X public-domain software?
 49)  [Removed]
 50)  [Removed]
 51)  [Removed]
 52)  [Removed]
 53)  [Removed]
 54)  [Removed]
 55)  [Removed]
 56)  Where can I obtain other X sources?
 57)  Where can I obtain interesting widgets?
 58)  Where can I obtain alternate language bindings to X?
 59)  What is the xstuff mail-archive?
 60)  [Removed]
 61)  [Removed]
 62)  [Removed]
 63)  [Removed]
 64)  [Removed]
 65)  [Removed]
 66)  [Removed]
 67)  Where can I get an "X terminal" server for my low-end Sun 3/50?
 68)  [Removed]
 69)  [Removed]
 70)  [Removed]
 71)  Where can I obtain an X-based plotting program?
 72)  [Removed]
 73)  [Removed]
 74)  [Removed]
 75)  [Removed]
 76)  Where can I get an X-based TeX or DVI previewer?
 77)  [Removed]
 78)  [Removed]
 79)  Where can I find X tools callable from shell scripts?
 80)  [Removed]
 81)  [Removed]
 82)  TOPIC: BUILDING THE X DISTRIBUTION
 83)  How do I build X with gcc?
 84)  [Removed]
 85)  What are these I/O errors running X built with gcc?
 86)  What are these problems compiling X11R4 with "gcc -traditional"?
 87)  What are these problems compiling X11R4 on the older Sun3?
 88)  What are these problems compiling the X11R4 server on SunOS 4.1.1?
 89)  What are these problems using R4 shared libraries on SunOS 4?
 90)  [Removed]
 91)  [Removed]
 92)  TOPIC: BUILDING X PROGRAMS
 93)  What is Imake?
 94)  Where can I get imake?
 95)  I have a program with an Imakefile but no Makefile. What to do?
 96)  Why can't I link to the Xlib shape routines?
 97)  What are these problems with "_XtInherit not found" on the Sun?
 98)  Why can't I compile my R3 Xaw contrib programs under R4?
 99)  TOPIC: PROGRAMMING PROBLEMS AND PUZZLES
100)  Why doesn't my program get the keystrokes I select for?
101)  How do I figure out what window manager is running?
102)  Is there a skeleton X program available?
103)  Why does XtGetValues not work for me?
104)  Why don't XtConfigureWidget/XtResizeWidget/XtMoveWidget work?
105)  How can my application tell if it is being run under X?
106)  How do I make a "busy cursor" while my application is computing?
107)  How do I query the user synchronously using Xt?
108)  How do I fork without hanging my parent X program?
109)  Why does XtAppAddInput not work as described?
110)  How do I simulate a button press/release event for a widget?
111)  Why doesn't anything appear when I run this simple program?
112)  What is the difference between a Screen and a screen?
113)  [Removed]
114)  How do I determine the name of an existing widget?
115)  What widget is appropriate to use as a drawing canvas?
116)  Why do I get a BadDrawable error drawing to XtWindow(widget)?
117)  Can XGetWindowAttributes get a window's background pixel/pixmap?
118)  Why doesn't GXxor produce mathematically-correct color values?
119)  Why does the pixmap I copy to the screen show up as garbage?
120)  How can my application iconify itself?
121)  How do I check whether a window ID is valid?
122)  Why can't my program work with tvtwm or swm?
123)  Can I have two applications draw to the same window?
124)  How do I keep a window from being resized by the user?
125)  How do I render rotated text?
126)  Why can't my program get a standard colormap?
127)  What is the X Registry? (How do I reserve names?)

If you have suggestions or corrections for any of these answers or any
additional information, please send them directly to [e-mail];
the information will be included in the next revision (or possibly the one
after that; thanks for the many suggestions which haven't been incorporated
yet).

This posting is intended to be distributed at approximately the beginning of
each month. New versions may be archived on export.lcs.mit.edu, uunet, and
132.206.1.1.

The information contained herein has been gathered from a variety of sources. In
many cases attribution has been lost; if you would like to claim responsibility
for a particular item, please let us know.

Conventions used below: telephone numbers tend to be Bell-system unless
otherwise noted; prices on items are not included.

All trademarks are the property of their respective owners.

----------------------------------------------------------------------
Subject:   0)  TOPIC: BASIC INFORMATION SOURCES AND DEFINITIONS
----------------------------------------------------------------------
Subject:   1)  What books and articles on X are good for beginners?

    Ken Lee of the DEC Western Software Laboratory ([e-mail])
regularly posts to comp.windows.x and ba.windows.x a bibliography containing
cites of all known reference books and how-to manuals and also cites of
selected technical articles on X and X programming; it is ftp-able as
    export.lcs.mit.edu:/contrib/Xbibliography and
    gatekeeper.dec.com:/archive/pub/X11/contrib/Xbibliography

Here is an unordered set of the reference books and tutorials most useful for
beginners; most appear on that list [comments are gathered from a variety of
places and are unattributable]:

Asente, Paul J., and Swick, Ralph R., "X Window System Toolkit, The Complete
Programmer's Guide and Specification", Digital Press, 1990.  The bible on Xt. A
treasury of information, excellent and invaluable.  Distributed by Digital
Press, ISBN 1-55558-051-3, order number EY-E757E-DP; and by Prentice-Hall,
ISBN 0-13-972191-6. Also available through DEC Direct at 1-800-DIGITAL.
[The examples are on export.lcs.mit.edu in contrib/ and on gatekeeper.dec.com
(16.1.0.2) in pub/X11/contrib as asente-swick.examples.tar.Z.  They were also
recently posted to comp.sources.x as xt-examples/part0[1-5].]

Jones, Oliver, Introduction to the X Window System, Prentice-Hall, 1988, 1989.
ISBN 0-13-499997-5. An excellent introduction to programming with Xlib.
Written with the programmer in mind, this book includes many practical tips
that are not found anywhere else. This book is not as broad as the O'Reilly
Xlib tutorial, but Jones is an experienced X programmer and this shows in the
quality and depth of the material in the book. Originally written for X11R1,
recent printings have included corrections and additions.  The sixth printing
should have X11R4 material.

Young, Doug. "The X Window System: Applications and Programming with Xt (Motif
Version)," Prentice Hall, 1989 (ISBN 0-13-497074-8). The excellent tutorial
"X Window Systems Programming and Applications with Xt," (ISBN 0-13-972167-3)
updated for Motif. [The examples from the Motif version are available on export
in ~ftp/contrib/young.motif.tar.Z]

Scheifler, Robert, and James Gettys, with Jim Flowers, Ron Newman, and David
Rosenthal, "X Window System: The Complete Reference to Xlib, X Protocol, ICCCM,
XLFD, Second Edition," Digital Press, 1990. "The Bible", an enhanced version of
X documentation by the authors of the Xlib documentation. This is the most
complete published description of the X programming interface and X protocol.
It is the primary reference work and is not introductory tutorial documentation;
additional tutorial works will usually be needed by most new X programmers.
Digital Press order EY-E755E-DP. DP ISBN 1-55558-050-5;
Prentice-Hall ISBN 0-13-972050-2

Nye, Adrian, "Xlib Programming Manual, Volume 1" and "Xlib Reference Manual,
Volume 2," O'Reilly and Associates, 1988. A superset of the MIT X documentation;
the first volume is a tutorial with broad coverage of Xlib, and the second
contains reference pages for Xlib functions and many useful reference
appendices.  ISBN 0-937175-26-9 (volume 1) and ISBN 0-937175-27-7 (volume 2).
[A version updated for X11R4 is available (4/90).]

Nye, Adrian, and Tim O'Reilly, "X Toolkit Programming Manual, Volume 4,"
O'Reilly and Associates, 1989. The folks at O'Reilly give their comprehensive
treatment to programming with the MIT Intrinsics; R4 versions are now
available, as is a Motif 1.1 version (Volume 4M).

O'Reilly, Tim, ed.,  "X Toolkit Reference Manual, Volume 5," O'Reilly and
Associates, 1989.  A professional reference manual for the MIT X11R3 Xt; some
information on X11R4 is included.

Mansfield, Niall. "The X Window System: A User's Guide," Addison-Wesley, 1989.
A tutorial introduction to using X, soon to be upgraded for R4.
ISBN 0-201-51341-2.

Miller, John David. "An Open Look at UNIX", M&T Books, 1990.  An Xt book with
information on OLIT and the OPEN LOOK extensions to for interfacing with the
file and workspace managers.  ISBN 1-55851-058-3 (with disk).

Quercia, Valerie and Tim O'Reilly. "X Window System User's Guide," O'Reilly and
Associates, 1989. A tutorial introduction to using X. ISBN 0-937175-36-6.
Also available in R4 and Motif flavors.

Rosenthal, David S.H., "Inter-Client Communication Conventions Manual Version
1.0 (MIT Consortium Standard)." The first real ICCCM, available on the R4 tape;
a version is also available from the xstuff mail-archive-server.

(Prentice-Hall ordering is 201-767-5937. O'Reilly ordering is 800-338-NUTS.)

In addition, check the X11R4 core distribution in doc/tutorials for some useful
papers and tutorials, particularly the file doc/tutorials/answers.txt.  "Late
Night's Top Ten X11 Questions" by Dave Lemke ([e-mail]) and Stuart Marks
([e-mail]) answers other common questions and some of these here in more
detail.

----------------------------------------------------------------------
Subject:   4)  What X-related public mailing lists are available?

    The xpert mailing list is the general, public mailing list on X
maintained by the X Consortium. The mailings are gatewayed, so xpert is almost
identical to the comp.windows.x Usenet newsgroup.

    ***    If you get comp.windows.x, you don't need to     ***
    ***    be added to the xpert mailing list.         ***

    Otherwise, you can join the list to receive X information
electronically. It is best to find a local distribution; perhaps someone within
your company is already receiving the mailing. As a last resort, send mail to
[e-mail] with a valid return electronic address.

    A mailing list for major X announcements (new releases, public reviews,
adoption of standards, but NOT advertisements, patches, or questions) is
available by request from [e-mail]. Messages sent to
xannounce will automatically be sent to the xpert mailing list.  They will not
be sent to the Usenet news group comp.windows.x; however, they will appear in
the Usenet news group comp.windows.x.announce.  Note: Only redistribution
addresses will be accepted for this list -- i.e. no personal addresses. If you
wish to receive xannounce yourself, please contact your mail administrator to
set up a local redistribution list and to put you on it.

    In addition, the X Consortium sponsors these public lists:
        bug-clx         CLX bug reports and discussions
        x-ada           X and ada
        x11-3d          people interested in X and 3d graphics
        ximage          people interested in image processing and X
        xvideo          discussion of video extensions for X
    To subscribe to one of these lists, assuming no-one in your
organization already receives it, send mail to <list>[e-mail]
with the Subject line including the name of the LIST in caps and the request
"addition request".  In the body of the message be sure to give an address for
your local distribution which is accessible from MIT (eddie.mit.edu).

    A mailing list for topics related to OPEN LOOK is sponsored by Greg
Pasquariello of Unify corporation; send to [e-mail] (or
[e-mail]) for information.
    A mailing list for bugs in the publicly-available version of XView
source, in particular, is sponsored by Sun; send for information to
[e-mail].
    A mailing list for topics related to Motif is sponsored by Kee Hinckley
of Alfalfa Software, Inc.; send to [e-mail] for information.
(This group is gatewayed to comp.windows.x.motif.)
    A mailing list for topics related to the XPM pixmap-format is sponsored
by Arnaud Le Hors of Group Bull; send to [e-mail] for
information. [1/91]
    A mailing list discussing InterViews can be subscribed to by sending to
[e-mail].
    A mailing list ([e-mail]) for topics related to the port
of X11 to the Amiga can be subscribed by sending to [e-mail] a
message containing
        Subject: Adding myself to AMIGA-X11
        SUBS AMIGA-X11 Your Real Name

----------------------------------------------------------------------
Subject:   5)  How do I ask a net-question so as to maximize helpful responses?

    When asking for help on the net or X mailing lists, be sure to include
all information about your setup and what you are doing.  The more specific you
are, the more likely someone will spot an error in what you are doing.  Without
all the details, people who want to help you often have to guess -- if they are
able to respond at all.

    Always mention what version of X you are using and where you got it
from. If your server came from a different source as the rest of your X system,
give details of that, too.  Give the machine type, operating system, and O/S
version for both the client and server machine.  It may also be appropriate to
mention the window manager, compiler, and display hardware type you are using.

    Then tell exactly what you are doing and exactly what happens.  If it is
a command that fails, include the exact transcript of your session in the
message.  If a program you wrote doesn't work the way you expect, include
as much of the source necessary for readers to reproduce the problem.

----------------------------------------------------------------------
Subject:   6)  What publications discussing X are available?

    The trade magazines (Unix World, Unix Review, Computer Language, etc.)
are publishing more articles on X. In addition to XNextEvent:

    - O'Reilly and Associates announced at the 5th MIT conference a
quarterly journal, The X Resource, devoted to a variety of X topics. Editorial
information: Adrian Nye, [e-mail].

    - The X Journal is slated to start bi-monthly publication September
1991 on a variety of X topics. Editorial information: Jerry Smith, Editor,
615-886-3429, [e-mail]. Subscription information:
The X Journal, Subscriber Services, Dept XXX, P.O. BOX 3000, Denville, NJ 07834,
USA.

----------------------------------------------------------------------
Subject:   7)  How can I meet other X developers? (What is XUG? AFUX? EXUG?)

    The national X User's Group was formed in January of 1988.  Its purpose
is to encourage X development by providing information on the X Window System
to all who are interested. [This FAQ is a service of XUG.]

    - Local Area Groups: [this list is always in the process of being
updated; some of these groups are known to be zombies]:
    Atlanta, GA        James Tio, 404-441-4784
    Bay Area, CA         Jim Turner, 415-960-0123
    Boston             Mitch Trachtenberg, [e-mail]
    Chicago            Jerry Walton, 219-736-2667
    Cleveland         Mike Kolberg, 216/243-1198
    Colorado        Jim West, 719/260-3463, [e-mail]
    South Florida ("SFXUG")    Gary M. Paxinos, 407-243-2405, [e-mail]
                Morgan Von Essen, [e-mail]
                Mahesh Neelakanta, [e-mail]
    Houston         Dinah G. McNutt, [e-mail]
                    713-798-5890
    Huntsville, Ala.    Pete Shea 205-837-9230
    Los Angeles ("LAX")    Debbie Catalano, [e-mail],
                213-322-5004 x194
    Michigan ("MIX")    JT Vogt, [e-mail], [phone]
                or Brian Smithson [phone]
    Pittsburgh, PA        John Kochmar, [e-mail]
                [phone]
    Princeton, NJ         Joe Camaratta, 609-734-6500
    Research Triangle Park     Steven Thiedke, 919/481-1353
    Washington, DC         Thomas Fagre, 703/866-7425

    Canada            Ken Ristevski, 416-470-1203
    Cambridge, UK        Ray Anderson, [phone]
    Israel            Warren Burstein, [e-mail]
                Yosi Ben-Harosh, [phone]
    Milan, Italy        Richard Glover, (39) 961-743-486
    Singapore        Chee Keong Law, 772-3116
                [e-mail]

    To join, form a local group, contribute to XNextEvent (the several-
times-yearly newsletter which includes articles of general interest, or help
out in any other way, contact Alex Fisher at XUG, c/o Integrated Computer
Solutions, 201 Broadway, Cambridge, MA 02139-9890, 617/621-0060#108, or email
to the human at [e-mail].

In addition, there are meetings of these groups:
    - Bay Area Motif Developers Group and Drinking Society
                    Ron Edmark [e-mail]

    The French X User Group is called AFUX and is based in Sophia Antipolis
by CERICS. Information can be obtained from Miss Vasseur or Miss Forest; BP 148;157, rue Albert Einstein; 06561 Valbonne Cedex; Phone: [phone] / 45 01;
Fax: [phone].  [10/90]

    The European X User Group was formed in 1989 to represent X users in
Europe.  It holds technical conferences at regular intervals. The EXUG also
publishes a regular newsletter which is distributed free of charge to members.
The EXUG also runs a email mailing list for members which is frequently used to
address issues of European interest in X. The EXUG can be contacted by email
at: [e-mail] or by snail mail at:  The EXUG, Mitchell House, 185 High
Street, Cottenham, Cambridge CB4 4RX, England; phone [phone].
[from Bevis King ([e-mail]), 4/90]

    GXUGiV is the German X User's Group in Vorbereitung ("in preparation")
being formed for X programmers and users; it is associated with the EXUG. All
interested should contact Olaf Heimburger ([phone]; and at
mcvax!unido!tub!olaf).

----------------------------------------------------------------------
Subject:   8)  What are these common abbreviations?

    Xt: The X Toolkit Intrinsics is a library layered on Xlib which
provides the functionality from which the widget sets are built. An "Xt-based"
program is an application which uses one of those widget sets and which uses
Intrinsics mechanisms to manipulate the widgets.
    Xmu: The Xmu library is a collection of Miscellaneous Utility functions
useful in building various applications and widgets.
    Xaw: The Athena Widget Set is the MIT-implemented sample widget set
distributed with X11 source since X11R2.
    Xm: The OSF/Motif widget set from the Open Software Foundation; binary
kits are available from many hardware vendors
    Xhp (Xw): The Hewlett-Packard Widget Set was originally based on R2++,
but several sets of patches exist which bring it up to R3, as it is distributed
on the X11R4 tapes. Supplemental patches are available to use it with R4.
    CLX: The Common Lisp X Interface is a Common Lisp equivalent to Xlib.
    XDMCP: The X Display Manager Protocol provides a uniform mechanism for
a display such as an X terminal to request login service from a remote host.
    XLFD: The X Logical Font Description Conventions describes a standard
logical font description and conventions to be used by clients so that they
can query and access those resources.
    RTFM: Common expert-speak meaning "please locate and consult the
relevant documentation -- Read the Forgotten Manual".
    UTSL: A common expression meaning "take advantage of the fact that you
aren't limited by a binary license -- Use The Source, Luke".

----------------------------------------------------------------------
Subject:   9)  What is the ICCCM? (How do I write X-friendly applications?)

    The Inter-Client Communication Conventions Manual is one of the
official X Consortium standards documents that define the X environment. It
describes the conventions that clients must observe to coexist peacefully with
other clients sharing the same server.  If you are writing X clients, you need
to read and understand the ICCCM,  in particular the sections discussing the
selection mechanism and the interaction between your client and the window
manager.  Get it either:
    - as part of the R4 distribution from MIT.
    - in the 2nd edition of the Scheifler/Gettys "X Window System" book.
    - as an appendix in the new version of O'Reilly's Volume 0, "X Protocol
Reference Manual." A version in old copies of their Volume 1 is obsolete.
    The version in the DP book is much more readable, thanks to the efforts
of Digital's editors to improve the English and the presentation.

[from David Rosenthal, 10/90]

    Alternate definition: the ICCCM is generally the M in "RTFM" and is
the most-important of the least-read X documents.

----------------------------------------------------------------------
Subject:  10)  What is the X Consortium, and how do I join?

    The MIT X Consortium was formed in January of 1988 to further the
development of the X Window System and has as its major goal the promotion of
cooperation within the computer industry in the creation of standard software
interfaces at all layers in the X Window System environment.
    MIT's role is to provide the vendor-neutral architectural and
administrative leadership required to make this work. Membership in the
Consortium open to any organization.  There are two categories of membership,
Member (for large organizations) and Affiliate (for smaller organizations).
    Most of the Consortium's activities take place via electronic mail,
with meetings when required.  As designs and specifications take shape,
interest groups are formed from experts in the participating organizations.
Typically a small multi-organization architecture team leads the design, with
others acting as close observers and reviewers.  Once a complete specification
is produced, it may be submitted for formal technical review by the Consortium
as a proposed standard.  The standards process typically includes public
review (outside the Consortium) and a demonstration of proof of concept.
    Your involvement in the public review process or as a Member or
Affiliate of the Consortium is welcomed.
    Write to: Bob Scheifler, MIT X Consortium, Laboratory for Computer
Science, 545 Technology Square, Cambridge, MA 02139.

[For complete information see the XCONSORTIUM man page from the X11R4
distribution, from which this information is adapted.] [2/90]

----------------------------------------------------------------------
Subject:  11)  Just what are OPEN LOOK and Motif?

    OPEN LOOK and Motif are two graphical user interfaces (GUIs). OPEN LOOK
was developed by Sun with help from AT&T and many industry reviewers; Motif was
developed by the Open Software Foundation (OSF) with input from many OSF
members.

    OPEN LOOK is primarily a user-interface specification and style-guide;
there are several toolkits which can be used to produce OPEN LOOK applications.
Motif includes an API specification; the only sanctioned Motif toolkit is the
one from OSF. However, there are other toolkits which can be used to produce
programs which look and behave like OSF/Motif; one of these, Solbourne's OI, is
a "virtual toolkit" which provides a common subset of OPEN LOOK and Motif, at
the user's choice.

    OPEN LOOK GUI is also the name of a product from AT&T, comprising
their OPEN LOOK Intrinsics Toolkit and a variety of applications.

[Thanks to Ian Darwin, [e-mail], 5/91]

----------------------------------------------------------------------
Subject:  14)  What is PEX?

    The PHiGS Extension to X is a proposed X Consortium standard awaiting
proof of concept; PHiGS stands for "Programmer's Hierarchical Interactive
Graphics System" and is essentially a library of functions that simplifies the
creation and manipulation of 3D graphics. Many platforms are capable of
performing in hardware the computations involved in rendering 3D objects; the
server extension would allow the client (PHIGS in this case) to take advantage
of the specialized hardware for 3D graphics.
    Sun Microsystems is currently contracted to develop a freely
redistributable (copyright similar to the current X copyright) sample
implementation.  The current schedule calls for a first non-beta release of
this implementation to be available to Consortium members in early 1991 and to
the world with X11R5. Several vendors are currently selling independently-
developed PEX servers for their workstations.
    The current PEX document is version V5.0P, on export.lcs.mit.edu in the
directory pub/PEX/.
[8/90; modified 12/90]

----------------------------------------------------------------------
Subject:  15)  TOPIC: USING X IN DAY-TO-DAY LIFE
----------------------------------------------------------------------
Subject:  16)  What are all these different window managers?

    The window manager in X is just another client -- it is not part of the
X window system, although it enjoys special privileges -- and so there is
no single window manager; instead, there are many which support different ways
for the user to interact with windows and different styles of window layout,
decoration, and keyboard and colormap focus. In approximate chronological order
(generally, the more recent ones are more conformant with the ICCCM):

    wm: this simple title-bar window manager was quickly phased out
    uwm: the Universal Window Manager is still popular for its speed,
although it is outdated. Moved to contrib/ on the R4 tape.
    twm (old): Tom's Window Manager was among the first non-MIT window
managers and offered the user a great deal of customization options in a
re-parenting window manager.
    awm: the Ardent Window Manager remains a hotbed for hackers and offers
some features (dynamic menus) not found on more current window managers
    cwm: cwm is part of the Andrew system. Notable for being the only
window manager whose name is also an English word.
    rtl: Siemen's window manager tiles windows so that they don't overlap
and resizes the window with the focus to its preferred size
    dxwm: Digital's dxwm is part of the DECwindows offering
    hpwm: HP's window manager offers a 3D look; it is a precursor of mwm
    mwm: the Motif window manager is part of the OSF/Motif toolkit
    tekwm: Tektronix's window manager offering
    olwm (Sun): olwm implements the OPEN LOOK GUI and some of the Style
Guide functionality
    olwm (AT&T): ditto
    gwm: Bull's Generic Window Manager emulates others with a built-in
Lisp interpreter
    m_swm: the Sigma window manager is on the R4 tape
    pswm: Sun's PostScript-based pswm is part of the OpenWindows release
    swm: Solbourne's swm is based on its OI toolkit and offers multiple
GUI support and also a panned virtual window; configuration information comes
from the resources file
    twm (new): MIT's new Tab Window Manager from the R4 tape is a reworked
twm and is the basis for several derivatives
    vtwm: vtwm offers some of the virtual-desktop features of swm, with a
single-root window implementation; it is based on the R4 twm
    tvtwm: Tom's Virtual Tab Window Manager is also based on the R4 twm
and provides a virtual desktop modeled on the virtual-root window of swm
    olvwm: the vtwm-style virtual-desktop added to Sun's olwm
    NCDwm: the window manager local to NCD terminals offers an mwm look
    XDSwm: the window manager local to Visual Technology's terminals

[5/91]

----------------------------------------------------------------------
Subject:  17)  Why does my X session exit when I kill my window manager?

    What is probably happening is that you are running your window manager
as the last job in your .xsession or .xinitrc file; your X session runs only as
long as the last job is running, and so killing your window manager is
equivalent to logging out. Instead, run the window manager in the background,
and as the last job instead invoke something safe like:
        exec xterm -name Login -rv -iconic
Your X session will continue until you explicitly logout of this window,
whether or not you kill your window manager.

----------------------------------------------------------------------
Subject:  18)  Is there a way for my WM to produce my .xinitrc, like toolplaces?

    Although no known window manager directly supports such a feature, there
is a contributed application which does much of what you are looking for,
although it is not as complete as the SunView program toolplaces. Look for the
application "xplaces" on an archive-server near you. There are several versions
of this program floating around; look for a recent vintage.
[10/90]

----------------------------------------------------------------------
Subject:  19)  How do I use another window manager with DEC's session manager?

    DEC's session manager will start dxwm up by default. To override this,
add to your .Xdefaults file something like this line, naming the full pathname:
    sm.windowManagerName:   /usr/bin/X11/your_favorite_wm

----------------------------------------------------------------------
Subject:  20)  How do I change the keyboard auto-repeat rate?

    You can turn auto-repeat on or off by using "xset r on|off". The X
protocol, however, doesn't provide for varying the auto-repeat rate, which is
a capability not supported by all systems.
    Some servers running on systems that support this (the Xsun server from
MIT, for example), however, may provide command-line flags to set the rate at
start-up time. If you have control over server start-up, you can invoke the
server with the chosen settings.

----------------------------------------------------------------------
Subject:  21)  How do I remap the keys on my keyboard to produce a string?

    There is no method of arranging for a particular string to be
produced when you press a particular key. The xmodmap client, which is useful
for moving your CTRL and ESC keys to useful places, just rearranges keys and
does not do "macro expansion."
    Some (few) clients, including xterm and several X-based editors,
accept a translation resource such as:
    xterm*VT100.Translations: #override \
        <Key>F1: string("setenv DISPLAY unix:0")
which permits the shorthand F1 to be pressed to reset the display locally
within an xterm; it takes effect for new xterm clients.
    Window managers, which could provide this facility, do not yet; nor
has a special "remapper" client been made available.

----------------------------------------------------------------------
Subject:  22)  How do I make a screendump of the X display?

    The xwd client in the R3 and R4 distributions can be used to select a
window or the background. It produces an XWD-format file of the image of that
window. The file can be post-processed into something useful or printed with
the xpr client and your local printing mechanism. You can use this command:
        csh% sleep 10; xwd -root > output.xwd &
and then spend 10 seconds or so setting up your screen; the entire current
display will be saved into the file output.xwd. Note that xwd also has an
undocumented -id flag for specifying the window id on the command-line.

    Two publicly-available programs which allow interactive definition of
arbitrary portions of the display and built-in delays are asnap and xgrabsc.
Xgrabsc was both recently [8/90] posted to comp.sources.x.
    xsnap includes some asnap features and supersedes it; it also renders
XPM output. It is available on export, as well. [11/90]

    Also: some vendors' implementations of X (e.g. DECWindows and
OpenWindows 2.0) include session managers or other desktop programs which
include "print portion of screen" or "take a snapshot" options.

    Also: some platforms have tools which can be used to grab the
frame-buffer directly. The Sun systems, for example, have a 'screendump'
program which produces a Sun raster file.

    Some vendors' implementations of lpr (e.g. Sony) include direct
support for printing xwd files, but you'll typically need some other package
to massage the output into a useful format which you can get to the printer.

    To post-process the xwd output of some of these tools, you can use xpr,
which is part of the R4 distribution. Also on several archives are xwd2ps
and XtoPS, which produce Encapsulated PostScript with trimmings suitable for
use in presentations (see export.lcs.mit.edu:contrib/xwd2ps.tar.Z and
contrib/ImageMagick.tar.Z). Also useful is the PBMPLUS package on many archive
servers.

----------------------------------------------------------------------
Subject:  23)  How do I make a color PostScript screendump of the X display?

    If you need color PostScript in particular, you can
    - grab the screen-image using xgrabsc to begin with, which can produce
color PostScript.
    - grab the screen-image using xwd and post-process xwd into color PS.
You can do this using xwd2ps or the XtoPS program from the ImageMagick
distribution. The PBMPLUS package is also good for this.

----------------------------------------------------------------------
Subject:  24)  How can I print the current selection?

    You could paste it into an xterm after executing the lpr command.
However, a program by Richard Hesketh ([e-mail]) specifically for
manipulating the selection will help; e.g.
    xselection PRIMARY | lpr
finds the primary selection and prints it. This command can be placed in a
window-manager menu or in shell-scripts. xselection also permits the setting of
the selection and other properties. It is probably available on fine
archive-servers everywhere.
    Also available is ria.ccs.uwo.ca:pub/xget_selection.tar.Z, which can be
adapted to do this.

----------------------------------------------------------------------
Subject:  25)  Why are my xterm menus so small?

    You are probably setting the geometry small accidentally. If you give
a resource specification like this:
        xterm*geometry: 80x24
then you are asking for all widgets under xterm to have their geometry set to
80x24. For the main window, this is OK, as it uses characters for its size.
But its popup menus don't; they are in pixels and show up small. To set only
the terminal widget to have the specified geometry, name it explicitly:
        xterm*VT100.geometry: 80x24

----------------------------------------------------------------------
Subject:  26)  Where can I find a dictionary server for xwebster?

    Webster's still owns the copyright to the on-line copies of Webster's
Dictionary which are found at various (university) sites. After it became aware
that these sites were then acting as servers for other sites running xwebster
and gnuemacs-webster, it asked that server sites close off external access.
    [The NeXT machine apparently is also licensed to have the dictionary. A
Webster daemon for NeXT machines is available from uvax.cs.indiana.edu
(129.79.254.192) in "pub/webster/NeXT-2.0".]
    Unless you want to get a legal on-line copy yourself or can find a site
which can grant you access, you are probably out of luck.

    However, if you are a legitimate site, you'll want to pick up the
latest xwebster, as-is on export:contrib/xwebster.tar.Z [11/90]; the file
xwebster.README includes discussions of the availability, illegality, and
non-availability of dictionary servers.

[courtesy [e-mail] (Steve Miller) and [e-mail] (Niels
Mayer) 11/90]

----------------------------------------------------------------------
Subject:  27)  How do I convert/view Mac/TIFF/GIF/Sun/PICT/img/FAX images in X?

    The likeliest program is an incarnation of Jef Poskanzer's useful++
Portable Bitmap Toolkit, which includes a number of programs for converting
among various image formats. It includes support for many types of bitmaps,
gray-scale images, and full-color images. PBMPLUS has been updated since it was
posted to the net about 11/22/89 and is also more recent than the one on the
R4 tape under contrib/clients/pbmplus. The current version is in "active beta"
[3/91] on export:/contrib/pbmplus.tar.Z.
    The package has been independently updated to support XPM images for
pixmaps. There are also several patches to various modules floating around.

    Useful for viewing some image-formats is Jim Frost's xloadimage, a
version of which is in the R4 directory contrib/clients/xloadimage -- there
are later versions available; version 3.0.1 shipped 5/91 and is on export
/contrib/xloadimage.3.01.tar.Z.

    An alternate image-viewer is xv (X Image Viewer), written by
[e-mail] (John Bradley) and distributed as comp.sources.x
Volume 10:79. It is also on export as xv.pl3.tar.Z. XV displays many image
formats and permits editing of GIF files, among others. [12/90]

    The Fuzzy Pixmap Manipulation, by Michael Mauldin <[e-mail]>.
Conversion and manipulation package, similar to PBMPLUS.  Version 1.0 available
via FTP as nl.cs.cmu.edu:/usr/mlm/ftp/fbm.tar.Z, uunet.uu.net:pub/fbm.tar.Z,
and ucsd.edu:graphics/fbm.tar.Z.

    The Img Software Set, by Paul Raveling <[e-mail]>, reads
and writes its own image format, displays on an X11 screen, and does some image
manipulations.  Version 1.3 is available via FTP on expo.lcs.mit.edu as
contrib/img_1.3.tar.Z, along with large collection of color images.

    Xim, by Philip R. Thompson, reads and writes its own image format,
displays on an X11 screen, and does some image manipulations.  Available in
your nearest X11R4 source tree as contrib/clients/xim.  A more recent version
is available via ftp from video.mit.edu.  It uses x11r4 and the OSF/Motif
toolkit to provide basic interactive image manipulation and reads/writes GIF,
xwd, xbm, tiff, rle, xim, and other formats.

    ImageMagick by [e-mail] can be retrieved as the file
contrib/ImageMagick.tar.Z (no patch level) from export.lcs.mit.edu.  It is a
collection of utilities to transform and display images on any X server. The
tool uses the MIFF format; filters to and from MIFF from other popular formats
(PPM, TIFF, GIF, SUN Raster, etc) are included.

    xtiff is a tool for viewing a TIFF file in an X window.  It was written
to handle as many different kinds of TIFF files as possible while remaining
simple, portable and efficient.  xtiff illustrates some common problems
with building pixmaps and using different visual classes.  It is distributed
as part of Sam Leffler's libtiff package and it is also available on
export.lcs.mit.edu, uunet.uu.net and comp.sources.x. [[e-mail], 10/90]
xtiff 2.0 was announced in 4/91; it includes Xlib and Xt versions.

    An alpha version of Lee Iverson's ([e-mail]) image-viewing
*widget* is available as /contrib/vimage.tar.Z on export.lcs.mit.edu and in
/pub/maspar on moe.mcrcim.mcgill.edu. [5/91] Look for patches, too. [6/91]

[some material from Larry Carroll ([e-mail]), 5/91]

----------------------------------------------------------------------
Subject:  28)  How can I change the titlebar of my xterm window?

    The solution involves sending an escape sequence to xterm which will
cause it to update the property which the window manager relies upon for the
string which appears in the window titlebar.
    A solution is as easy as typing this in an xterm running a shell:
        echo "ESC]2;TEXT^G"
where ESC is the escape key, TEXT is the string you wish to have displayed,
and ^G is a Control-G (the BEL character).

    Here is a more complicated csh alias which changes the titlebar to
the current working directory when you change directories:
        alias newcd 'cd \!* ; echo ESC]2\;$cwd^G'

    The digit '2' in these strings indicates to xterm that it should
change only the title of the window; to change both the title and the name
used in the icon, use the digit '0' instead, and use '1' to change only the
icon name.

    These sequences work for both R3 and R4 xterm windows; the R4 xterm,
however, does not accept the looser sequences which worked under R3 and
demands a semicolon, above, for example, where the R3 xterm allowed any
character.

    Note: another way to do this, which prevents an incorrect display of
the local directory if a modified `cd` is used in a subshell, is to wrap the
escape sequences into the PS1 prompt itself.

----------------------------------------------------------------------
Subject:  29)  Where can I find the xterm control sequences? [edited]

The best source of such information is the file mit/clients/xterm/ctlseqs.ms.

This document is not installed as part of the installation.

In a pinch, a VT100 manual will do.

----------------------------------------------------------------------
Subject:  30)  How do I keep my $DISPLAY when I rlogin to another machine?

    There are several ways to avoid having to do a "setenv DISPLAY ..."
whenever you log in to another networked UNIX machine running X.
    One solution is to use the xrlogin program from der Mouse
([e-mail]). You can ftp caveat-emptor versions from
132.206.1.1, in X/xrlogin.c and X/xrlogind.c. The program packages up $TERM and
$DISPLAY into a single string, which is stuffed into $TERM.  rlogin then
propagates $TERM normally; your .cshrc on the remote machine should contain
        eval `xrlogind`
where xrlogind is a program that checks $TERM and if it is of the special
format it recognizes, unpacks it and spits out setenv and unsetenv commands to
recreate the environment variables. [11/90]

    In addition, if all you need to do is start a remote X process on
another host, and you find
        rsh <HOST> -n /usr/bin/X11/xterm -display $DISPLAY
too simple (DISPLAY must have your real hostname), then this version of xrsh
can be used to start up remote X processes. The equivalent usage would be
        xrsh <HOST> xterm

  #! /bin/sh
  # start an X11 process on another host
  # Date: 8 Dec 88 06:29:34 GMT
  # From: Chris Torek <[e-mail]>
  # rsh $host -n "setenv DISPLAY $DISPLAY; exec $@ </dev/null >&/dev/null"
  #
  # An improved version:
  # rXcmd (suggested by John Robinson, [e-mail])
  #       (generalized for sh,ksh by Keith Boyer, [e-mail])
  #
  # but they put the rcmd in ()'s which left zombies again.  This
  # script combines the best of both.

  case $# in
  [01])  echo "Usage: $0 host x-cmd [args...]";;
  *)
      case $SHELL in
      *csh*)  host="$1"; shift
          xhost "$host" > /dev/null
          rsh "$host" -n \
              "setenv TERM xterm; setenv DISPLAY `hostname`:0; \
              exec $* </dev/null >& /dev/null" &
          ;;
      *sh)
          host="$1"; shift
          xhost "$host" > /dev/null
          rsh "$host" -n \
              "TERM=xterm export TERM; \
              DISPLAY=`hostname`:0 export DISPLAY; \
              LD_LIBRARY_PATH=/usr/X11/lib export LD_LIBRARY_PATH; \
              PATH=\$PATH:/usr/X11/bin:/usr/bin/X11:/usr/local/bin; \            export PATH; \
              exec $* < /dev/null > /dev/null 2>&1" &
          ;;
      esac
      ;;
  esac

----------------------------------------------------------------------
Subject:  31)  How can I design my own font?

    One way is to use the "bitmap" client or some other bitmap-editor (e.g.
Sun's icon-editor tool, post-processed with pbmplus) to design the individual
characters and then to do some large amount of post-processing to concatenate
them into the BDF format.
    The R3 contrib/ area (in fonts/utils/ and in clients/xtroff) contained
a number of useful utilities, including some to convert between BDF font format
and a simple character format which can be edited with any text editor.
    An easier way is to use the "xfed" client to modify an existing font; a
recent version is on the R4 tape in contrib/clients/xfed. Xfed is available for
anonymous ftp on unido.informatik.uni-dortmund.de (129.217.64.60) as file
/pub/windows/X/Diverse-X11-Sourcen/xfed.tar.Z.
    The xfedor client from Group Bull permits creation of bitmaps, cursors,
XPM1 pixmaps, and fonts. Binaries for common machines are on
avahi.inria.fr/pub; in addition, the sources, with plenty of caveats, have been
placed [5/91] in export:/contrib.
    If you are a MetaFont user you can use "mftobdf" from the SeeTeX
distribution to convert PK, GF, and PXL fonts to BDF format; the distribution
is on foobar.colorado.edu and on export.lcs.mit.edu.

----------------------------------------------------------------------
Subject:  32)  Why does adding a font to the server not work?

    After you have built the font using your system's font-compiler,
installed it in some directory, and run `mkfontdir` or your system's equivalent
in that directory, be sure to use `xset +fp $dir` to add that full path-name to
the server's font-path, or if the directory is already in the path, use
`xset fp rehash` so that the new fonts in that directory are actually found; it
is this last step that you're probably leaving out.

----------------------------------------------------------------------
Subject:  33)  How do I convert a ".snf" font back to ".bdf" font?

    A tool called "snftobdf 1.4" is part of the bdftools package, which is
available from export.lcs.mit.edu:contrib/bdftools.tar.Z and from
crl.nmsu.edu:pub/misc/bdftools.tar.Z. Sources have been posted to fj.sources on
JUNET and should be appearing on comp.sources.x. [2/91]

----------------------------------------------------------------------
Subject:  34)  What is a general method of getting a font in usable format?

    der Mouse's getbdf is one solution; it connects to a server and
produces a .BDF file for any font the server is willing to let it.  It can be
used as an anything-to-BDF converter, but requires access to a server that can
understand the font file, thus is both more and less powerful than other tools
such as snftobdf. getbdf is on 132.206.1.1 in X/getbdf.c or available via mail
from [e-mail]. [5/91]

----------------------------------------------------------------------
Subject:  35)  How do I use HP ".scf" fonts on my MIT R4 server?

    The X server from HP uses fonts whose names have the .scf suffix. These
are just compressed .snf fonts which are produced with the normal bdftosnf
program.  You should be able to uncompress the font and add it to your font
area, possibly with a rename to .snf. Remember to run mkfontdir and to rehash
the font path.

----------------------------------------------------------------------
Subject:  36)  How do I use DECwindows ".pcf" fonts on my MIT R4 server?

    The DECwindows server stores fonts in a ".pcf" format which is not
recognized by the X11R4 server. There are several "font extractor" tools that
you can use to get the .pcf files from the DEC server and write the information
to a .bdf file, which you can then recompile to .snf fonts using the
font-compiler from the MIT distribution; the bdftools package is reported to
contain such an extractor.

----------------------------------------------------------------------
Subject:  37)  How do I use DECwindows fonts on my non-DECwindows server?

    The DECwindows fonts typically don't exist on a non-DEC installation,
but rewrite rules can be used to alias fonts used by DECwindows applications to
standard MIT fonts of similar characteristics and size. Pick up the file
contrib/DECwindows_on_X11R4_font.aliases from export.lcs.mit.edu; this file is
for a standard MIT R4 server.  It can also serve as a starting point for
creating a similar aliases file for the Open Windows server or other servers
which do not use the MIT font scheme.

----------------------------------------------------------------------
Subject:  38)  How do I add ".bdf" fonts to my DECwindows server?

    The format of fonts preferred by DEC's X server is the ".pcf" format.
You can produce this compiled format from the .bdf format by using DEC's dxfc
font-compiler. Note that the DEC servers can also use raw .bdf fonts, with a
performance hit.

----------------------------------------------------------------------
Subject:  39)  Why can't I set the backgroundPixmap resource in a defaults file?
I want to be able to do something like this:
    xclock*backgroundPixmap:      /usr/include/X11/bitmaps/rootweave

    You can't do this. The backgroundPixmap resource is a pixmap of the
same depth as the screen, not a bitmap (which is a pixmap of depth 1). Because
of this, writing a generic String to Pixmap converter is impossible, since
there is no accepted convention for a file format for pixmaps. Therefore,
neither the X Toolkit or the Athena widget set define a String to Pixmap
converter, because there is no converter you cannot specify this value as a
resource.  The Athena widget set does define a String to Bitmap converter for
use in many of its widgets, however.
[courtesy Chris D. Peterson (now [e-mail]), 4/90]

However:
    A specific converter which encapsulates much of the functionality of the
xloadimage package by Jim Frost was posted 12/90 by Sebastian Wangnick
([e-mail]); it permits loading of a number of
image formats as a pixmap.

    The leading general-purpose format for pixmaps is the XPM format used
by Groupe Bull in several of its programs, including the GWM window manager, by
AT&T in its olpixmap editor, and by ICS in its interface builder. XPM
distribution, available on export as contrib/xpm.tar.Z, includes read/write
routines which can easily be adapted to converters by new widgets which want to
allow specification of pixmap resources in the above manner.  See information
on the xpm-talk mailing list above. XPM 3.0a was announced in 4/91 and is
available from export.lcs.mit.edu and avahi.inria.fr.

----------------------------------------------------------------------
Subject:  40)  Why does the R3 xterm, et al, fail against the R4 server?

    The value given to a window's do_not_propagate mask is the likely
culprit.  R3 allowed bogus values to be set, and early version of both Andrew
and Interviews did, as well. Similar problems also occur in the R3 Motif
PanedWindow widget.
    If it is impossible to fix client source, use 'xset bc' to put the
X11R4 server into bug-compatibility mode.

----------------------------------------------------------------------
Subject:  42)  How can I have xclock or oclock show different timezones?

    One solution is xchron, in Volume 6 of comp.sources.x, which can show
the time for timezones other than the local one.
    Alternatively, you can probably set the timezone in the shell from
which you invoke the xclock or oclock, or use a script similar to this:
    #!/bin/sh
    TZ=PST8PDT xclock -name "San Jose" 2> /dev/null &
    TZ=EST5EDT xclock -name "Cambridge" 2> /dev/null &

----------------------------------------------------------------------
Subject:  43)  I have xmh, but it doesn't work. Where can I get mh?

    The xmh mail-reader requires the Rand mh mail/message handling system,
which is not part of the UNIX software distribution for many machines. The
current version of mh is typically on ics.uci.edu in /mh; it was updated in
mid-December 1990 to 6.7.1. [1/91]

----------------------------------------------------------------------
Subject:  44)  Why am I suddenly unable to connect to my Sun X server?
After a seemingly random amount of time after the X server has been started, no
other clients are able to connect to it.

    The default cron cleanup jobs supplied by Sun (for 4.0.3, at least)
delete "old" (unreferenced) files from /tmp -- including /tmp/.X11-unix, which
contains the socket descriptor used by X. The solution is to add "! -type s" to
the find exclusion in the cron job.
[10/90]

----------------------------------------------------------------------
Subject:  45)  Why can't I override translations? Only the first item works.

    You probably have an extra space after the specification of the first
item, like this:
    basic*text.translations:  #override \
    Ctrl<Key>a:    beginning-of-line() \n\
    Ctrl<Key>e:    end-of-line()
                          ^ extra space
The newline after that space is ending the translation definition.
[Thanks to Timothy J. Horton, 5/91]

----------------------------------------------------------------------
Subject:  46)  How do I report bugs in X?

    Generally, report bugs you find to the organization that supplied you
with the X Window System. If you received the source distribution directly from
MIT, please read the file mit/doc/bugs/bug-report for instructions (see also
"getting patches for R4", below).

----------------------------------------------------------------------
Subject:  47)  TOPIC: OBTAINING X AND RELATED SOFTWARE AND HARDWARE
----------------------------------------------------------------------
Subject:  48)  Is X public-domain software?

    No. The X software is copyrighted by various institutions and is not
"public domain", which has a specific legal meaning. However, the X
distribution is available for free and can be redistributed without fee.
    Contributed software, though, may be placed in the public domain by
individual authors.

----------------------------------------------------------------------
Subject:  56)  Where can I obtain other X sources?

    User-contributed software is distributed through the newsgroup
comp.sources.x, moderated by Dan Heller ([e-mail]); also check that group
for posting information.

    Richard Hesketh ([e-mail]) has been creating a list of freely-
available X sources.  The list is stored on export.lcs.mit.edu in contrib as
x-source-list.Z. It lists the main storage locations for the program and
international sites from which it may be ftp'ed.

    The machine export.lcs.mit.edu has a great deal of user-contributed
software in the contrib/ directory; a good deal of it is present in current or
earlier versions on the X11R3 and X11R4 contrib tapes. There is a new directory
contrib/R4fixes/ for fixes to R4 contrib software. [Jim Fulton, 2/90]

    The material on giza.cis.ohio-state.edu, which tends to duplicate
the export archives, is also available via anonymous UUCP from osu-cis, at TB+
and V.32 speeds.  Write to [e-mail] (same as osu-cis!uucp) for
instructions. [the archive is now maintained by Karl Kleinpaste]

    A new west-coast UUCP X11 Archive is administered by Mark Snitily
([e-mail]) and contains the full X11R4 distribution, the XTEST
distribution, an entire archive of comp.sources.x and other goodies.
    The machine zok has a TB+ modem which will connect to 19.2K, 2400,
1200 baud (in that order).  The anonymous UUCP account is UXarch with password
Xgoodies.  The modem's phone number is 408-996-8285.
    A sample Systems (or L.sys) entry might be:
           zok Any ACU 19200 4089968285 in:--in: UXarch word: Xgoodies
    To get a current listing of the files that are available, download
the file "/usrX/ls-lR.Z".
    A full subject index of the comp.sources.x files is available in the
file "/usrX/comp.sources.x/INDEX".
    The machine has just the one modem, so please do not fetch large
amounts of data at one sitting.
[courtesy Mark Snitily, 2/90]


FTP sites and software available:
This list is a lightly-edited (e.g. `grep X`) condensation of sites posted by
[e-mail] (Jon Granrose) [9/90].

a.cs.uiuc.edu                      128.174.252.1   TeX, dvi2ps, gif, texx2.7
avahi.inria.fr                     192.5.60.47     xfedor
brazos.rice.edu                    128.42.42.2     pub/X11R3/core.src
cayuga.cs.rochester.edu            192.5.53.209    Xfig, JOVE, NL-KR mail list
cheddar.cs.wisc.edu                128.105.2.143   Common Lisp stuff, X11
crl.dec.com                        192.58.206.2    X11R4
cs.toronto.edu                     128.100.1.65    UofT BIND, X applications
dinorah.wustl.edu                  128.252.118.101 X11R3/core.src, portability
dolphin.mit.edu                    18.86.0.5       X11r3 device driver for S,
emil.csd.uu.se                     130.238.4.2     Old GNU, X R10
export.lcs.mit.edu                 18.30.0.238     X, portable bitmaps, CLX and
 export.lcs.mit.edu                                  CLUE, gwm
extro.ucc.su.oz.au                 129.78.64.1     images, gnu, icon, kermit,
 extro.ucc.su.oz.au                                Ghostscript patches
faui43.informatik.uni-erlangen.de  131.188.1.43    NeWS X11 amiga atari faces
fcs280s.ncifcrf.gov                129.43.1.11     xtrek5.4
finsun.csc.fi                      128.214.46.40   X11R4 ftp-list
foobar.colorado.edu                128.138.243.105 BDF fonts, xtex
freja.diku.dk                      129.142.96.1    nn, gnu, x11r4, tex, isode
fresnel.stanford.edu               36.10.0.77      X11R4 for Iris
gatekeeper.dec.com                 16.1.0.2        X11, recipes, cron, map
giza.cis.ohio-state.edu            128.146.8.61    X, PEX
hemuli.tik.vtt.fi                  130.188.52.2    WorldMap X bind.4.8 finger
hpcvaaz.cv.hp.com                  15.255.72.15    MitX11R4 Motif
hpserv1.uit.no                     128.39.60.50    HP stuff, X11, unix, etc
hydra.helsinki.fi                  128.214.4.29    misc, TeX, X
interviews.stanford.edu            36.22.0.175     InterViews X toolkit
iraun1.ira.uka.de                  129.13.10.90    GNU X11 comp.sources.unix
irisa.irisa.fr                     131.254.2.3        comp.sources.x
 j.cc.purdue.edu                   128.210.5.1     comp.sources.x
jpl-mil.jpl.nasa.gov               128.149.28.2    TeX, mac, GNU, X11R2, X11R3
kappa.rice.edu                     128.42.4.7      X11R3, GNU for Sequent S27
labrea.stanford.edu                36.8.0.47       GNU, X, official TeX sources
larry.mcrcim.mcgill.edu            132.206.4.3     RFCs, X, local nameserver
lll-crg.llnl.gov                   128.115.1.1     X11R4
ltisun.epfl.ch                     128.178.38.6    xconq
m9-520-1.mit.edu                   18.80.0.45      xim utils
maddog.llnl.gov                    128.115.10.1    AWM X tutorial, PCP
mcs213k.cs.umr.edu                 131.151.6.11    xgif, shuttle
me10.lbl.gov                       128.3.128.110   X11 binaries for hp-ux, me10
nic.funet.fi                       128.214.6.100   GNU, X11, networking, msdos,
oddput.efd.lth.se                  130.235.48.4    xps (postscript previewer)
peace.waikato.ac.nz                130.217.64.62   x11r4
polyslo.calpoly.edu                129.65.17.1     xtrek, top 2.0, spaceout,
qed.rice.edu                       128.42.4.38     GNU, X11R3, plot2ps sources
research.att.com                   192.20.225.2    TeX, gcc, ghostscript, f2c
scam.berkeley.edu                  128.32.138.1    X sources, etc.
schizo.samsung.com                 134.228.1.2     comp.sources.x
sequent.kent.edu                   131.123.2.50    x11r4 for esix
shambhala.berkeley.edu             128.32.132.54   xrn, xgraph
shemp.cs.ucla.edu                  131.179.128.34  XWIP
sirius.ucs.adelaide.edu.au         129.127.40.3    X11R4
slug.pws.bull.com                  128.35.10.203   comp.sources.x, gif, X11R4,
 slug.pws.bull.com                                 X11R3, R4contrib, gnu,
ti.com                             128.247.159.141 CLX
trout.nosc.mil                     132.249.16.12   X11R3, benchmarks, popd, GNU
ucbvax.berkeley.edu                128.32.130.12   nntp, gnews, awm, empire
unido.informatik.uni-dortmund.de   129.217.64.60   atari, mac, benchmarks,
 unido.informatik.uni-dortmund.de                  utils, x11, sysadm tools
vaxa.isi.edu                       128.9.0.33      clf-act, X, db
winnie.princeton.edu               128.112.128.180 music software (unix & NeXT)
 wpi.wpi.edu                                       TeX_DS3100, TeX_Umax, misc X
wuarchive.wustl.edu                128.252.135.4   GNU, X.11R3, GIF, IEN, RFCs,
 wuarchive.wustl.edu                               comp.sources.x, msdos,
xanth.cs.odu.edu                   128.82.8.1      comp.sources.x,
 xanth.cs.odu.edu                  128.82.4.1      comp.sources.games, X10R4
xview.ucdavis.edu                  128.120.1.150   xview

These sites mirror export and are of particular use for Australasia:
    Anonymous ftp: ftp.Adelaide.EDU.AU      pub/X/R4/
                        pub/sources/x/
    ACSnet Fetchfile: sirius.ua.oz          X/R4/
                        sources/x/

In addition, UUNET Source Archives (703-876-5050) tracks comp.sources.x and
provides 800MB+ of compressed programs on 6250 bpi tapes or 1/4" tapes
(or Exabyte 8mm cartridges?).

----------------------------------------------------------------------
Subject:  57)  Where can I obtain interesting widgets?

    The Free Widget library sponsored by Brian Totty ([e-mail]) is
now [12/90] available on a.cs.uiuc.edu (128.174.252.1) in pub/fwf.shar.Z. The
set of widgets there is intended to form the basis for future contributions. To
be added to the discussion list, contact free-widgets-request@
eagle.cnsf.cornell.edu. The current set includes a pixmap editor.
    Additional widgets are available on the contrib/ portion of the X11R4
tapes; these include the Xcu set.
    O'Reilly Volume 4, Doug Young's book, the Asente/Swick book, and Jerry
Smith's "Object-oriented Programming with the X Window System Toolkits" all
include details on writing widgets and include several useful widgets; sources
are typically on export and/or UUNET.
    The Dirt interface builder includes the libXukc widet set which extends
the functionality of Xaw.
    A graph widget and other 2D-plot and 3D-contour widgets by Sundar
Narasimhan ([e-mail]) are available from ftp.ai.mit.edu as
/com/ftp/pub/users/sundar/graph.tar.Z. The graph widget has been updated [3/91]
with documentation and histogram capabilities.
    Ken Lee's Xm widget (beta) that uses Display PostScript to draw labels
at a non-horizontal angle is on export in contrib/dpslabel.tar.Z.

    An alpha version of Lee Iverson's ([e-mail]) image-viewing
*widget* is available as /contrib/vimage.tar.Z on export.lcs.mit.edu and in
/pub/maspar on moe.mcrcim.mcgill.edu. The package also includes an
ImageViewPort widget and a FileDialog widget. [5/91]
    Other available file-requestor widgets include the FileSelector from the
Free Widget Foundation, the XiFileSelector from Iris Software's book, and
the xdbx file-selector extracted by David Nedde ([e-mail]).

----------------------------------------------------------------------
Subject:  58)  Where can I obtain alternate language bindings to X?

    Versions of the CLX Lisp bindings are part of the X11R3 and X11R4 core
source distributions. The latest version of CLX (R4.5) is available from export
for ftp as contrib/CLX.R4.5.tar.Z. [6/91]

    Ada bindings were written by Mark Nelson and Stephen Hyland at SAIC
for the DOD. The bindings can be found on hapo.sei.cmu.edu or on
wsmr-simtel20.army.mil and are also in the Ada Software Repository (ASR).
R3 bindings should be available by the end of 1/90. [1/90]

    Prolog bindings (called "XWIP") written by Ted Kim at UCLA while
supported in part by DARPA are available by anonymous FTP from
export.lcs.mit.edu:contrib/xwip.tar.Z or ftp.cs.ucla.edu:pub/xwip.tar.Z.
These prolog language bindings depend on having a Quintus-type foreign function
interface in your prolog. The developer has gotten it to work with Quintus and
SICStus prolog. Inquiries should go to [e-mail]. [3/90]

    GHG is developing X bindings and a complete Ada re-implementation
of X; check Lionel Hanley at 713-488-8806. [4/90]

    Ada bindings to Motif, explicitly, will eventually be made available by
the Jet Propulsion Laboratories, probably through the normal electronic
means.  Advance information can be obtained from [e-mail],
who may respond as time permits.
    Another set of bindings for Motif 1.1 is being done by the University of
Lowell; it can be ftp'ed from 129.63.1.1 as Motif1.1-g++.tar.Z in
graphics/MotifC++. A Technical Report on the binding is included. [4/91]

----------------------------------------------------------------------
Subject:  59)  What is the xstuff mail-archive?

    The xstuff server is a mail-response program. That means that you mail
it a request, and it mails back the response.
    Any of the four possible commands must be the first word on a line. The
xstuff server reads your entire message before it does anything, so you can
have several different commands in a single message (unless you ask for help).
The xstuff server treats the "Subject:" header line just like any other line
of the message.
    The archives are organized into a series of directories and
subdirectories.  Each directory has an index, and each subdirectory has an
index. The top-level index gives you an overview of what is in the
subdirectories, and the index for each subdirectory tells you what is in it.

    1) The command "help" or "send help" causes the server to send you a
more detailed version of this help file.
    2) if your message contains a line whose first word is "index", then
the server will send you the top-level index of the contents of the archive. If
there are other words on that line that match the name of subdirectories, then
the indexes for those subdirectories are sent instead of the top-level index.
For example, you can say "send index fixes" (or "index fixes"). A message that
requests an index cannot request data.
    3) if your message contains a line whose first word is "send", then the
xstuff server will send you the item(s) named on the rest of the line. To name
an item, you give its directory and its name. For example
                send fixes 1 3 4
    You may issue multiple send requests. The xstuff server contains many
safeguards to ensure that it is not monopolized by people asking for large
amounts of data. The mailer is set up so that it will send no more than a fixed
amount of data each day. If the work queue contains more requests than the
day's quota, then the unsent files will not be processed until the next day.
Whenever the mailer is run to send its day's quota, it sends the requests out
shortest-first.
    4) Some mailers produce mail headers that are unusable for extracting
return addresses.  If you use such a mailer, you won't get any response.  If
you happen to know an explicit path, you can include a line like
        path [e-mail]
or
        path bar!foo!frotz
in the body of your message, and the daemon will use it.

    The xstuff server itself can be reached at [e-mail]. If
your mailer deals in "!" notation, try sending to
{someplace}!mit-eddie!expo.lcs.mit.edu!xstuff.

[based on information from the MIT X Consortium, 8/89, 4/90.]

----------------------------------------------------------------------
Subject:  67)  Where can I get an "X terminal" server for my low-end Sun 3/50?

    Seth Robertson ([e-mail]) has written Xkernel; the current
version [1.2 gamma as of 3/91, 2.0 expected RSN] is on sol.ctr.columbia.edu
[128.59.64.40] in /pub/Xkernel.gamma. It turns a Sun 3/50 into a pseudo- X
terminal; most of the overhead of the operating system is side-stepped, so it
is fairly fast and needs little disk space.
    A similar approach is to run the regular X server by making /etc/init
a shell script which does the minimal setup and then invokes Xsun, like this
script from [e-mail]:

#! /bin/sh
exec >/dev/console 2>&1
/etc/fsck -p /dev/nd0
case $? in
     0)    ;;
     4)    /etc/reboot -q -n
         ;;
     8)    echo ND fsck failed - get help
         /etc/halt
         ;;
     12)    echo Interrupted
         /etc/reboot
         ;;
     *)    echo Unknown error in reboot fsck - get help
         /etc/halt
         ;;
esac
/bin/dd if=/tmp-fs of=/dev/nd2 bs=512 count=128 >/dev/null 2>&1
/etc/mount /dev/nd2 /tmp
/etc/ifconfig le0 netmask 255.255.255.0 broadcast 132.206.41.255
/etc/mount -o ro apollo:/u2/x11/lib /local/lib/X11
/etc/route add default 132.206.41.1 1 >/dev/null
set `/etc/ifconfig le0`
exec /Xsun -once -multidisp -mux -query `(sh -vn </local/lib/X11/xdm-servers/$2 2>&1)`

----------------------------------------------------------------------
Subject:  71)  Where can I obtain an X-based plotting program?

These are mostly available from uucp sites such as uunet or other sites as
marked.

 gnuplot    X (xplot), PostScript and a bunch of other drivers.
    cs.duke.edu:/dist/sources/gnuplot/gnuplot2.02.tar.Z [128.109.140.1]
    monu1.cc.monash.edu.au:/pub/gnuplot2.02.tar.Z [130.194.1.101]
    irisa.irisa.fr:/pub/gnuplot2.02.tar.Z [131.254.2.3]
    comp.sources.misc/volume8

 gl_plot    X output only [?]
    comp.sources.unix/volume18

 graph+
    yallara.cs.rmit.oz.au:/pub/graph+.tar.Z [131.170.24.42]
    comp.sources.unix/volume8

 pdraw,drawplot        2D and 3D X,PS
    scam.berkeley.edu:/src/local/3dplot.tar.Z [128.32.138.1]
    scam.berkeley.edu:/src/local/contour.tar.Z [128.32.138.1]
    scam.berkeley.edu:/src/local/drawplot.tar.Z [128.32.138.1]
    uunet:~ftp/contrib/drawplot.tar.Z

 xgraph        plot, zoom. Outputs PS or HPGL.
    shambhala.berkeley.edu:/pub/xgraph-11.tar.Z [128.32.132.54]
    sun1.ruf.uni-freiburg.de:X11/contrib/xgraph-11.tar.Z [132.230.1.1]
    nisc.jvnc.net:pub/xgraph-11.tar.Z [128.121.50.7]
    comp.sources.x/volume3
    or many other sites

 xvgr        An XView xgraph++ program.
    sun.soe.clarkson.edu:pub/src/xvgr-1.06alpha.tar.Z [128.153.12.3]
    uvax.rrz.uni-koeln.de:pub/windows/xcontrib/xvgr-1.06alpha.tar.Z

[2/91. Thanks to:
[e-mail] (Ed Vielmetti) ; [e-mail] (Geoffrey Leach) ;
Paul A. Scowen ([e-mail]) ;  [e-mail] (Mike Black)]

----------------------------------------------------------------------
Subject:  76)  Where can I get an X-based TeX or DVI previewer?

    The xtex previewer for TeX files is available from a number of archive
sites, including uunet; the current version is usually on foobar.colorado.edu
(128.138.243.105) in SeeTeX-2.17.0.tar.Z; pre-converted fonts are also on that
machine. The distribution all includes "mftobdf" which converts PK, GF, and PXL
fonts to BDF format, where they can then be compiled for use by your local X
server. Xtex 2.17 was announced 3/1/91.
    The xdvi dvi-previewer is fairly comprehensive and easy to use. It is
also available from a number of sites, including uunet and export.lcs.mit.edu.

----------------------------------------------------------------------
Subject:  79)  Where can I find X tools callable from shell scripts?
I want to have a shell script pop up menus and yes/no dialog boxes if the user
is running X.

    Several tools in the R3 contrib/ area were developed to satisfy these
needs: yorn pops up a yes/no box, xmessage displays a string, etc. There are
several versions of these tools; few, if any, have made it to the R4 contrib/
area, though they may still be available on various archive sites.
    In addition, Richard Hesketh ([e-mail]) has posted the xmenu
package to comp.sources.x ("v08i008: xmenu") for 1-of-n choices.  [7/90]
    Two versions of XPrompt have been posted to comp.sources.x, the latter
being an unauthorized rewrite. [R. Forsman ([e-mail]), 1/91]
    There is a version of XMenu available from comp.sources.x; it is
being worked on and will likely be re-released.

----------------------------------------------------------------------
Subject:  82)  TOPIC: BUILDING THE X DISTRIBUTION
----------------------------------------------------------------------
Subject:  83)  How do I build X with gcc?

    MIT is now using regularly the Free Software Foundation's
GNU-CC to build the X distribution and uses gcc-built servers to test
performance increases.

    [These options are gathered from several descriptions of building
X with gcc 1.34, 1.35, and 1.36, and are possibly outdated]:

    Use the options
        -O -fstrength-reduce -fpcc-struct-return

        -traditional may also be necessary if your version of
gcc is sufficiently old (but don't use with 1.38).

    Do not use -finline-functions, particularly on the R4 server.

    --->    Make sure to run 'fixincludes' from the gcc distribution
    --->    before doing anything, or you will get fatal errors such as:
    --->    xterm: Error 15, errno 25: Inappropriate ioctl for device.

HOWEVER, there is a bug in gcc 1.34 and 1.36 (but not in 1.35 or 1.37) which
miscompiles things of the form (expr == 0 ? exp1 : exp2).  The fix needed in
X11R4 (and probably X11R3) is to change the definition of XtNewString in
Intrinsic.h to:
  #define XtNewString(str) \
  ((str) != NULL ? (strcpy(XtMalloc((unsigned)strlen(str) + 1), str)) : NULL)
A work-around is also in fix-2 to X11R4.

----------------------------------------------------------------------
Subject:  85)  What are these I/O errors running X built with gcc?
When I try to run xinit or the Xsun server I get the error
    "Getting interface configuration: Operation not supported on socket.
    Fatal server bug! no screens found."

    Running the gcc fixincludes script apparently didn't work. You can do
this simple test:

    #include <sys/ioctl.h>
    SIOCGIFCONF

Run that through cc -E and gcc -E.  The last line of output is the piece of
interest; it should be identical (modulo irrelevant differences like
whitespace).  If the gcc version has 'x' where the cc version has 'i', your
fixincludes run didn't work for some reason or other; go back to your gcc
sources and run `fixincludes`; then rebuild the X distribution. If they are
identical, try running a make clean in mit/server and rebuilding, just to make
sure everything gets compiled with the proper include files.

[courtesy der Mouse, [e-mail]; 9/90]

----------------------------------------------------------------------
Subject:  86)  What are these problems compiling X11R4 with "gcc -traditional"?

    There are known problems with gcc 1.38 which cause use of the
-traditional to produce errors along the lines of "gcc: Program cpp got fatal
signal 6". The fix is to upgrade to 1.39.

[from Darryl Okahata ([e-mail]); 2/91]

----------------------------------------------------------------------
Subject:  87)  What are these problems compiling X11R4 on the older Sun3?
In mit/server/ddx/sun/sunCG3C.c, we have found "missing" defines for
CG3AC_MONOLEN, CG3BC_MONOLEN, CG3AC_ENBLEN, CG3BC_ENBLEN. What should these be?

    The R4 Errata list distributed after X11R4 mentions that you can add
these lines to the file on older SunOS versions (e.g. 3.5) to compile:
        #define CG3AC_MONOLEN (128*1024)
        #define CG3AC_ENBLEN  CG3AC_MONOLEN
        #define CG3BC_MONOLEN CG3AC_MONOLEN
        #define CG3BC_ENBLEN  CG3AC_MONOLEN

    However, the Sun3 should not actually ever have the CG3 device, and so
references to it can be removed from mit/server/ddx/sun/sunInit.c and the
Imakefile.  [11/90]

----------------------------------------------------------------------
Subject:  88)  What are these problems compiling the X11R4 server on SunOS 4.1.1?
The file <sundev/cg6reg.h> isn't being found.

    Sun omitted <sundev/cg6reg.h> from SunOS 4.1.1. Remove the #include
from sunCG6C.c and replace it with the line
    #define CG6_VADDR_COLOR   0x70016000
The file has changed from earlier versions of SunOS and should not be copied
from another distribution.

----------------------------------------------------------------------
Subject:  89)  What are these problems using R4 shared libraries on SunOS 4?
All of the executables that I try to run have the following results:
    ld.so: libXmu.so.4: not found
or even:
    ld.so: call to undefined procedure __GetHostname from 0xf776a96c

    If you are building with shared libraries on a Sun, remember that you
need to run "ldconfig" as root after installing the shared libraries (if you've
installed X on a file-server, run it on the server's clients, too).  While
building and installing the distribution, you need to be careful to avoid
linking against any existing X shared libraries you might have (e.g. those
distributed with OpenWindows).  You should make sure you do not have
LD_LIBRARY_PATH set in your environment during the build or the installation.
If you are going to keep xterm and xload as setuid programs, please note that
the shared libraries must be installed in /usr/lib, /usr/local/lib, or
/usr/5lib for these programs to work (or else those programs must be linked
statically). [courtesy MIT X Consortium]
    Note also that the program mkfontdir is run as part of the build; it
attempts, however, to use the shared libraries before they have been installed.
You can avoid the errors by building mkfontdir statically (pass -Bstatic to
most C compilers).

----------------------------------------------------------------------
Subject:  92)  TOPIC: BUILDING X PROGRAMS
----------------------------------------------------------------------
Subject:  93)  What is Imake?

    Imake is not a replacement for the make program; instead, it is a
makefile-generator that takes advantages of the include-file and macro-
processing capabilities of the C preprocessor cpp to generate makefiles
suitable for building software on a particular system. Although it is not
specific to X, the X release uses it to help solve a number of the
configuration issues that arise in making such a large system widely portable.
    Imake has a fairly steep learning curve, in part because the process by
which the system-specific configuration files, system-independent configuration
files, and individual Imakefiles are melded to produce a Makefile is not
obvious.
    You can obtain information on imake from these sources:
    - Paul Dubois ([e-mail]) has written a useful
explanation of how Imake works and how to use it in configuring X for non-
supported systems; the document is available from indri.primate.wisc.edu
(128.104.230.11) in the directory ~ftp/pub/imake-stuff; look for
config-X11R4.ms (troff) and config-X11R4.ps (PostScript). Some supplemental
appendices are nearby.
    - the R4 release notes and imake man page include information on using
Imake to build X
    - on the R4 tapes, contrib/doc/imake/imake.tex is Mark Moraes' R3/R4
guide to imake.
    - and check the R4 mit/config directory for the source files

[1/91]

----------------------------------------------------------------------
Subject:  94)  Where can I get imake?

    A version is distributed with the X11R4 release. An earlier version is
distributed with the X11R3 release; some third-party toolkits redistribute
versions of imake along with their own implementations of the template and
configuration files. There are no real standards for such configuration files,
although most current contributed software expects the templates distributed
with X11R4.
    There are no known archive sites which have imake in a form in which
it can be downloaded without downloading most of the X11 release. [2/91]

----------------------------------------------------------------------
Subject:  95)  I have a program with an Imakefile but no Makefile. What to do?

    If you have R4 installed on your system, run "xmkmf". This is a script
which runs imake for you with the correct arguments. The output is a Makefile
configured for your system and based on the Imakefile. Then run make, which
will use that new Makefile to compile the program.

----------------------------------------------------------------------
Subject:  96)  Why can't I link to the Xlib shape routines?
When I try to compile certain programs, I get the following link error:
    Undefined:
    _XShapeQueryExtension
    _XShapeCombineMask

    These routines are actually part of the Shape Extension to X (SHAPE)
which was introduced in the MIT X11R4 distribution and allows non-rectangular
windows.  Like the other sample server extensions, the shape extension will
only run on a server which supports it.  Pre-X11R4 servers, as well as many
vendor-supplied servers, do not support the shape extension, in which case
they will display rectangular windows anyway.

    In order to use the shape extension, you must link to the library
libXext.a.  In the X11R4 distribution, this library and the associated includes
will be in the mit/extensions directory.  If you do not have these files, do
not despair:  many freeware programs which use the shape extension can also be
compiled without it by removing the -DSHAPE define from the Makefile; you can
probably do this and compile successfully against your older vendor-supplied X
libraries.

[from John B. Melby, [e-mail], 3/91]

----------------------------------------------------------------------
Subject:  97)  What are these problems with "_XtInherit not found" on the Sun?
When I run a X program that I wrote on a SunOS 4.0.3 or 4.1 machine I get the
error "ld.so: symbol not found _XtInherit".

    What you are seeing is a side-effect of a kludge in the R4 libXt.a to
get Sun shared libraries working.  Apparently, you can't share a function that
is both called and compared, as _XtInherit is. This was handled by putting
_XtInherit in the same file as a function that is always used, thereby
guaranteeing that it would be loaded -- that is, in Initialize.c, where
XtToolkitInitialize() and XtInitialize() reside. These routines would normally
be called.

    You are probably seeing this error because your program is not a normal
Xt-based program and does not call XtToolkitInitialize() anywhere.
    1) it may be a program that uses Xt functions but never opens a
connection to the X server.  [OSF/Motif's 1.1.0 UIL had this problem; it called
XtMalloc() and other Xt functions.] The solution is to add the call to your
program; the function does not have to be executed, just linked in.
    2) alternatively, your program doesn't need any Xt functions and is
correct in not calling XtToolkitInitialize() -- it may be an Xlib or XView
program. In this case, you can remove -lXt from your link command.

    It should not be necessary to link the shared libraries statically,
although this will certainly solve the problem.

[from Jordan Hayes (now [e-mail]) and Danny Backx ([e-mail]); 11/90]

----------------------------------------------------------------------
Subject:  98)  Why can't I compile my R3 Xaw contrib programs under R4?
I have a program that worked well under X11R3. When I try to link it under
X11R4, I get this message:
    Undefined:
    _XtScrollBarSetThumb
    _XtTextSetInsertionPoint
    _XtTextReplace

    There were several name changes in the Athena widget set (in addition
to the header files moving into <X11/Xaw/>); these are mentioned in the R4
release notes. In this case, these functions are not really Xt functions but
are part of the Xaw text widget and so have been renamed from Xt* to Xaw*.
[10/90]

----------------------------------------------------------------------
Subject:  99)  TOPIC: PROGRAMMING PROBLEMS AND PUZZLES
----------------------------------------------------------------------
Subject: 100)  Why doesn't my program get the keystrokes I select for?

    The window manager controls how the input focus is transferred from one
window to another.  In order to get keystrokes, your program must ask the
window manager for the input focus.  To do this, you must set up what are
called "hints" for the window manager.  If your applications is Xlib-based, you
can use something like the following:

        XWMHints wmhints;
        ...
        wmhints.flags = InputHint;
        wmhints.input = True;
        XSetWMHints(dpy, window, &hints)


If your application is based on the Xt Intrinsics, you can set the XtNinput
resource to be True (as you probably want to in any case); if you don't have
source, you can start up the application with the resource '*input:True'.

Certain window managers, notably dxwm and olwm, are very picky about having
this done.

    If you are using Sun's OpenWindows olwm, you can also add this resource
to your defaults file to use clients that aren't ICCCM-compliant.
    OpenWindows.FocusLenience:       true

[mostly courtesy Dave Lemke of NCD and Stuart Marks of Sun]

----------------------------------------------------------------------
Subject: 101)  How do I figure out what window manager is running?

    You can't reliably tell; whatever mechanism you could use could be
spoofed in any case.
    For most cases, you shouldn't care which window manager is running, so
long as you do things in an ICCCM-conformant manner. There are some cases in
which particular window managers are known to do things wrong; checking for
particular hints placed on the window by the window manager so that you can
sidestep the problem may be appropriate in these cases. Alternatively, it may
be appropriate to determine which window manager is running in order to take
advantage of specific added features (such as olwm's push-pin menus).

----------------------------------------------------------------------
Subject: 102)  Is there a skeleton X program available?

    There is no general framework such as the TransSkel program for the
Macintosh which handles lots of the odds and ends and overhead of development
under a window system and which can be used as a platform for additional
development. In X, the problem is typically solved by using an interactive
application builder tool or by using cut&paste on existing X applications. Good
applications which you might look to manipulate when you want to "test just
this one little thing" include contrib/clients/xskel, a simple R4 program that
puts up a window and allows sketching in it and offers a starting point for
quick hacks, the Xaw examples in the examples/ directory in the R3 and R4
distributions, and the Xlib "Hello World" example in the R3 doc/HelloWorld and
R4 doc/tutorials/HelloWorld; an updated version of this program which uses R4
Xlib calls and current ICCCM conventions was posted in 2/90 to comp.windows.x
by Glenn Widener of Tektronix.     [3/90]

----------------------------------------------------------------------
Subject: 103)  Why does XtGetValues not work for me?

    The XtGetValues interface for retrieving resources from a widget is
sensitive to the type of variable. Your code may be doing something like this:
    {
    Arg args[3];
    int i;
    int sensitive;        /* oops; wrong data type */
    i=0;
    XtSetArg (args[i], XtNsensitive, &sensitive); i++;
    XtGetValues(widget, args, i );
    ...
    }

But XtNsensitive is a Boolean, which on most machines is a single byte;
declaring the variable "sensitive" as Boolean works properly. This problem
comes up often when using particular toolkits that redefine the Xt types
Dimension and Position; code that assumes they are int will have similar
problems if those types are actually short. In general: you are safe if you
use the actual type of the resource, as it appears in the widget's man page.
[11/90]

----------------------------------------------------------------------
Subject: 104)  Why don't XtConfigureWidget/XtResizeWidget/XtMoveWidget work?

    You're probably trying to use these functions from application code.
They should be used only internally to widgets; these functions are for a
parent widget to change the geometry of its children. Other promising functions,
XtMakeGeometryRequest() and XtMakeResizeRequest(), are also for use only by
widgets, in this case by a child to request a change from its parent.
    The only way for your application to request a geometry change for a
widget is to issue an XtSetValues call setting some of the geometry resources.
Although this will result in the widget-internal functions' being called, your
application code must use the standard XtSetValues interface or risk the
widgets' data becoming corrupted.

----------------------------------------------------------------------
Subject: 105)  How can my application tell if it is being run under X?

    A number of programs offer X modes but otherwise run in a straight
character-only mode. The easiest way for an application to determine that it is
running on an X display is to attempt to open a connection to the X server:

    display = XOpenDisplay(display_name);
    if (display)
        { do X stuff }
    else
        { do curses or something else }
where display_name is either the string specified on the command-line following
-display, by convention, or otherwise is (char*)NULL [in which case XOpenDisplay
uses the value of $DISPLAY, if set].

This is superior to simply checking for the existence a -display command-line
argument or checking for $DISPLAY set in the environment, neither of which is
adequate. [5/91]

----------------------------------------------------------------------
Subject: 106)  How do I make a "busy cursor" while my application is computing?
Is it necessary to call XDefineCursor() for every window in my application?

    The easiest thing to do is to create a single InputOnly window that is
as large as the largest possible screen; make it a child of your toplevel
window and it will be clipped to that window, so it won't affect any other
application. (It needs to be as big as the largest possible screen in case the
user enlarges the window while it is busy or moves elsewhere within a virtual
desktop.) Substitute "toplevel" with your top-most widget here (similar code
should work for Xlib-only applications; just use your top Window):

     unsigned long valuemask;
     XSetWindowAttributes attributes;

     /* Ignore device events while the busy cursor is displayed. */
     valuemask = CWDontPropagate | CWCursor;
     attributes.do_not_propagate_mask =  (KeyPressMask | KeyReleaseMask |
         ButtonPressMask | ButtonReleaseMask | PointerMotionMask);
     attributes.cursor = XCreateFontCursor(XtDisplay(toplevel), XC_watch);

     /* The window will be as big as the display screen, and clipped by
        its own parent window, so we never have to worry about resizing */
     XCreateWindow(XtDisplay(toplevel), XtWindow(toplevel), 0, 0,
         65535, 65535, (unsigned int) 0, CopyFromParent, InputOnly,
         CopyFromParent, valuemask, &attributes);

When you want to use this busy cursor, map and raise this window; to go back to
normal, unmap it. This will automatically keep you from getting extra mouse
events; depending on precisely how the window manager works, it may or may not
have a similar effect on keystrokes as well.

In addition, note also that most of the Xaw widgets support an XtNcursor
resource which can be temporarily reset, should you merely wish to change the
cursor without blocking pointer events.

[thanks to Andrew Wason ([e-mail]), Dan Heller ([e-mail]),
and [e-mail]; 11/90,5/91]

----------------------------------------------------------------------
Subject: 107)  How do I query the user synchronously using Xt?

    It is possible to have code which looks like this trivial callback,
which has a clear flow of control. The calls to AskUser() block until answer
is set to one of the valid values. If it is not a "yes" answer, the code drops
out of the callback and back to an event-processing loop:

    void quit(w, client, call)
        Widget          w;
        XtPointer client, call;
    {
        int             answer;
        answer = AskUser(w, "Really Quit?");
        if (RET_YES == answer)
            {
            answer = AskUser(w, "Are You Really Positive?");
            if (RET_YES == answer)
                exit(0);
                }
    }

    A more realistic example might ask whether to create a file or whether
to overwrite it.
    This is accomplished by entering a second event-processing loop and
waiting until the user answers the question; the answer is returned to the
calling function. That function AskUser() looks something like this, where the
Motif can be replaced with widget-set-specific code to create some sort of
dialog-box displaying the question string and buttons for "OK", "Cancel" and
"Help" or equivalents:

  int AskUser(w, string)
        Widget          w;
        char           *string;
  {
        int             answer=RET_NONE;    /* some not-used marker */
        Widget          dialog;            /* could cache&carry, but ...*/
        Arg             args[3];
        int             n = 0;
        XtAppContext    context;

        n=0;
        XtSetArg(args[n], XmNmessageString, XmStringCreateLtoR(string,
                XmSTRING_DEFAULT_CHARSET)); n++;
        XtSetArg(args[n], XmNdialogStyle, XmDIALOG_APPLICATION_MODAL); n++;
        dialog = XmCreateQuestionDialog(XtParent(w), string, args, n);
        XtAddCallback(dialog, XmNokCallback, response, &answer);
        XtAddCallback(dialog, XmNcancelCallback, response, &answer);
        XtAddCallback(dialog, XmNhelpCallback, response, &answer);
        XtManageChild(dialog);

        context = XtWidgetToApplicationContext (w);
        while (answer == RET_NONE || XtAppPending(context)) {
                XtAppProcessEvent (context, XtIMAll);
        }
        XtDestroyWidget(dialog);    /* blow away the dialog box and shell */
        return answer;
  }

    The dialog supports three buttons, which are set to call the same
function when tickled by the user.  The variable answer is set when the user
finally selects one of those choices:

  void response(w, client, call)
        Widget          w;
        XtPointer client;
        XtPointer call;
  {
  int *answer = (int *) client;
  XmAnyCallbackStruct *reason = (XmAnyCallbackStruct *) call;
        switch (reason->reason) {
        case XmCR_OK:
                *answer = RET_YES;    /* some #define value */
                break;
        case XmCR_CANCEL:
                *answer = RET_NO;
                break;
        case XmCR_HELP:
                *answer = RET_HELP;
                break;
        default:
                return;
        }
}

and the code unwraps back to the point at which an answer was needed and
continues from there.

[Thanks to Dan Heller ([e-mail]); further code is in Dan's R3/contrib
WidgetWrap library. 2/91]

----------------------------------------------------------------------
Subject: 108)  How do I fork without hanging my parent X program?

    An X-based application which spawns off other Unix processes which
continue to run after it is closed typically does not vanish until all of its
children are terminated; the children inherit from the parent the open X
connection to the display.
    What you need to do is fork; then, immediately, in the child process,
    close (ConnectionNumber(XtDisplay(widget)));
to close the file-descriptor in the display information. After this do your
exec. You will then be able to exit the parent.

[Thanks to Janet Anstett ([e-mail]) and Gordon Freedman
([e-mail]) 2/91]

----------------------------------------------------------------------
Subject: 109)  Why does XtAppAddInput not work as described?
I am using XtAppAddInput to read from a file, but the function is called even
when there isn't input pending.

    XtAppAddInput is actually working as it is supposed to. When used on
files, it is called whenever the file is READY to be read, not when there is
new data to be read. The file is almost always ready to be read, however, if
only because you can spin back to the beginning and read data you've read
before. The result is that your function will almost always be called every
time around XtMainLoop(). There is a way to get the type of interaction you are
expecting; add this line to the beginning of your function to test whether
there is new data:
         if (ioctl(fd, FIONREAD, &n) == -1 || n == 0) return;
But, because this is called frequently, your application is effectively in a
busy-wait; you may be better off not using XtAppAddInput and instead setting a
timer and in the timer procedure checking the file for input.

[courtesy Dan Heller ([e-mail]), 8/90; [e-mail] 5/91]

----------------------------------------------------------------------
Subject: 110)  How do I simulate a button press/release event for a widget?

    You can do this using XSendEvent(); it's likely that you're not setting
the window field in the event, which Xt needs in order to match to the widget
which should receive the event.
     If you're sending events to your own application, then you can use
XtDispatchEvent() instead. This is more efficient than XSendEvent() in that you
avoid a round-trip to the server.

[courtesy Mark A. Horstman ([e-mail]), 11/90]

----------------------------------------------------------------------
Subject: 111)  Why doesn't anything appear when I run this simple program?

> ...
> the_window = XCreateSimpleWindow(the_display,
>      root_window,size_hints.x,size_hints.y,
>      size_hints.width,size_hints.height,BORDER_WIDTH,
>      BlackPixel(the_display,the_screen),
>      WhitePixel(the_display,the_screen));
> ...
> XSelectInput(the_display,the_window,ExposureMask|ButtonPressMask|
>     ButtonReleaseMask);
> XMapWindow(the_display,the_window);
> ...
> XDrawLine(the_display,the_window,the_GC,5,5,100,100);
> ...

    You are right to map the window before drawing into it. However, the
window is not ready to be drawn into until it actually appears on the screen --
until your application receives an Expose event. Drawing done before that will
generally not appear. You'll see code like this in many programs; this code
would appear after window was created and mapped:
  while (!done)
    {
      XNextEvent(the_display,&the_event);
      switch (the_event.type) {
    case Expose:     /* On expose events, redraw */
        XDrawLine(the_display,the_window,the_GC,5,5,100,100);
        break;
    ...
    }
    }

    Note that there is a second problem: some X servers don't set up the
default graphics context to have reasonable foreground/background colors, and
your program should not assume that the server does, so this program could
previously include this code to prevent the case of having the foreground and
background colors the same:
  ...
  the_GC_values.foreground=BlackPixel(the_display,the_screen);    /* e.g. */
  the_GC_values.background=WhitePixel(the_display,the_screen);    /* e.g. */
  the_GC = XCreateGC(the_display,the_window,
                GCForeground|GCBackground,&the_GC_values);
  ...

Note: the code uses BlackPixel and WhitePixel to avoid assuming that 1 is
black and 0 is white or vice-versa.  The relationship between pixels 0 and 1
and the colors black and white is implementation-dependent.  They may be
reversed, or they may not even correspond to black and white at all.

----------------------------------------------------------------------
Subject: 112)  What is the difference between a Screen and a screen?

    The 'Screen' is an Xlib structure which includes the information about
one of the monitors or virtual monitors which a single X display supports. A
server can support several independent screens. They are numbered unix:0.0,
unix:0.1, unix:0.2, etc; the 'screen' or 'screen_number' is the second digit --
the 0, 1, 2 which can be thought of as an index into the array of available
Screens on this particular Display connection.
    The macros which you can use to obtain information about the particular
Screen on which your application is running typically have two forms -- one
which takes a Screen and one with takes both the Display and the screen_number.
    In Xt-based programs, you typically use XtScreen(widget) to determine
the Screen on which your application is running, if it uses a single screen.
    (Part of the confusion may arise from the fact that some of the macros
which return characteristics of the Screen have "Display" in the names --
XDisplayWidth, XDisplayHeight, etc.)

----------------------------------------------------------------------
Subject: 114)  How do I determine the name of an existing widget?
I have a widget ID and need to know what the name of that widget is.

    R4 users are best off using the XtName() function, which will work
on both widgets and non-widget objects.

    If you are still using R3, you can use this simple bit of code to do
what you want. Note that it depends on the widget's internal data structures
and is not portable to future versions of Xt, including R4.

    #include <X11/CoreP.h>
    String XtName (widget)
    Widget widget;    /* will not work with non-widget objects */
    {
    return widget->core.name;
    }

[7/90]

----------------------------------------------------------------------
Subject: 115)  What widget is appropriate to use as a drawing canvas?

    Some widget sets have a widget particularly for this purpose -- a
WorkSpace or DrawingArea which doesn't display anything but lets your Xt
application know when it has been re-exposed, resized, and when it has received
user key and mouse input.
    The best thing to do for other widget sets -- including the Athena set
-- is to create or obtain such a widget; this is preferable to drawing into a
core widget and grabbing events with XtAddEventHandler(), which loses a number
of benefits of Xt and encapsulation of the functionality .  At least one
version has been posted to comp.sources.x (name???). The publicly-available
programs xball and xpic include other versions. And Chapter 7 of the Athena
Widget manual includes a tutorial and source code to a simple Window widget
which is suitable for use.

----------------------------------------------------------------------
Subject: 116)  Why do I get a BadDrawable error drawing to XtWindow(widget)?
I'm doing this in order to get a window into which I can do Xlib graphics
within my Xt-based program:

> canvas = XtCreateManagedWidget ( ...,widgetClass,...) /* drawing area */
> ...
> window = XtWindow(canvas);    /* get the window associated with the widget */
> ...
> XDrawLine (...,window,...);    /* produces error */

    The window associated with the widget is created as a part of the
realization of the widget.  Using a window id of NULL ("no window") could
create the error that you describe.  It is necessary to call XtRealizeWidget()
before attempting to use the window associated with a widget.
    Note that the window will be created after the XtRealizeWidget() call,
but that the server may not have actually mapped it yet, so you should also
wait for an Expose event on the window before drawing into it.

----------------------------------------------------------------------
Subject: 117)  Can XGetWindowAttributes get a window's background pixel/pixmap?

    No.  Once set, the background pixel or pixmap of a window cannot be
re-read by clients.  The reason for this is that a client can create a pixmap,
set it to be the background pixmap of a window, and then free the pixmap. The
window keeps this background, but the pixmap itself is destroyed.  If you're
sure a window has a background pixel (not a pixmap), you can use XClearArea()
to clear a region to the background color and then use XGetImage() to read
back that pixel.  However, this action alters the contents of the window, and
it suffers from race conditions with exposures. [courtesy Dave Lemke of NCD
and Stuart Marks of Sun]

    Note that the same applies to the border pixel/pixmap. This is a
(mis)feature of the protocol which allows the server is free to manipulate the
pixel/pixmap however it wants.  By not requiring the server to keep the
original pixel or pixmap, some (potentially a lot of) space can be saved.
[courtesy Jim Fulton, MIT X Consortium]

----------------------------------------------------------------------
Subject: 118)  Why doesn't GXxor produce mathematically-correct color values?

    When using GXxor you may expect that drawing with a value of black on a
background of black, for example, should produce white. However, the drawing
operation does not work on RGB values but on colormap indices. The color that
the resulting colormap index actually points to is undefined and visually
random unless you have actually filled it in yourself. [On many X servers Black
and White often 0/1 or 1/0; programs taking advantage of this mathematical
coincidence will break.]
    If you want to be combining colors with GXxor, then you should be
allocating a number of your own color cells and filling them with your chosen
pre-computed values.
    If you want to use GXxor simply to switch between two colors, then you
can take the shortcut of setting the background color in the GC to 0 and the
foreground color to a value such that when it draws over red, say, the result
is blue, and when it draws over blue the result is red. This foreground value
is itself the XOR of the colormap indices of red and blue.

[Thanks to Chris Flatters ([e-mail]) and Ken Whaley
([e-mail]), 2/91]

----------------------------------------------------------------------
Subject: 119)  Why does the pixmap I copy to the screen show up as garbage?

    The initial contents of pixmaps are undefined.  This means that most
servers will allocate the memory and leave around whatever happens to be there
-- which is usually garbage.  You probably want to clear the pixmap first using
XFillRectangle() with a function of GXcopy and a foreground pixel of whatever
color you want as your background (or 0L if you are using the pixmap as a
mask). [courtesy Dave Lemke of NCD and Stuart Marks of Sun]

----------------------------------------------------------------------
Subject: 120)  How can my application iconify itself?

    The ICCCM provides a mechanism for this; your application sends a
client message which includes a data value indicating that it wishes to be
iconified.  Here is a sample callback that will iconify the application shell,
wait 3 seconds, and pop it back up. Note that ApplicationShellWidget below
is global; it would make more sense in real use to walk up the tree via
XtParent() to find the shell containing the active widget.

   void IconifyShell(w, d1, d2)
        Widget w;
        caddr_t d1, d2;
   {
     XClientMessageEvent event;
     Window win;
     Display *dpy;

     event.type = ClientMessage;
     event.send_event = True;
     dpy = event.display = XtDisplay(w);
     win = event.window = XtWindow(ApplicationShellWidget);
     event.message_type = XInternAtom(dpy, "WM_CHANGE_STATE", False);
     event.format = 32;
     event.data.l[0] = IconicState;
     XSendEvent(dpy, DefaultRootWindow(dpy), False,
                SubstructureRedirectMask | SubstructureNotifyMask, &event);
     XFlush(dpy);
     sleep(3);
     XMapWindow(dpy,win);
   }

[courtesy David Brooks ([e-mail]), 4/90]

R4 users may find it easier to use this routine:
    /*
     * This function instructs the window manager to change this window from
     * NormalState to IconicState.
     */
    Status XIconifyWindow (dpy, w, screen)
        Display *dpy;
        Window w;
        int screen;

----------------------------------------------------------------------
Subject: 121)  How do I check whether a window ID is valid?
My program has the ID of a window on a remote display. I want to check whether
the window exists before doing anything with it.

    Because X is asynchronous, there isn't a guarantee that the window would
still exist between the time that you got the ID and the time you sent an event
to the window or otherwise manipulated it. What you should do is send the event
without checking, but install an error handler to catch any BadWindow errors,
which would indicate that the window no longer exists. This scheme will work
except on the [rare] occasion that the original window has been destroyed and
its ID reallocated to another window.

[courtesy Ken Lee ([e-mail]), 4/90]

----------------------------------------------------------------------
Subject: 122)  Why can't my program work with tvtwm or swm?

    A number of applications, including xwd, xwininfo, and xsetroot, do not
handle the virtual root window which tvtwm and swm use; they typically return
the wrong child of root. A general solution is to add this code or to use it in
your own application where you would normally use RootWindow(dpy,screen):

/* Function Name: GetVRoot
 * Description: Gets the root window, even if it's a virtual root
 * Arguments: the display and the screen
 * Returns: the root window for the client
 */
#include <X11/Xatom.h>
Window GetVRoot(dpy, scr)
Display        *dpy;
int             scr;
{
Window          rootReturn, parentReturn, *children;
unsigned int    numChildren;
Window          root = RootWindow(dpy, scr);
Atom            __SWM_VROOT = None;
int             i;

  __SWM_VROOT = XInternAtom(dpy, "__SWM_VROOT", False);
  XQueryTree(dpy, root, &rootReturn, &parentReturn, &children, &numChildren);
  for (i = 0; i < numChildren; i++) {
    Atom            actual_type;
    int             actual_format;
    long            nitems, bytesafter;
    Window         *newRoot = NULL;

    if (XGetWindowProperty(dpy, children[i], __SWM_VROOT, 0, 1,
        False, XA_WINDOW, &actual_type, &actual_format, &nitems,
            &bytesafter, (unsigned char **) &newRoot) == Success && newRoot) {
            root = *newRoot;
            break;
        }
    }

    return root;
}

[courtesy David Elliott ([e-mail]). Similar code is in ssetroot, a
version of xsetroot distributed with tvtwm. 2/91]

A header file by Andreas Stolcke of ICSI on export.lcs.mit.edu:contrib/vroot.h
functions similarly by providing macros for RootWindow and DefaultRootWindow;
code can include this header file first to run properly in the presence of a
virtual desktop.

----------------------------------------------------------------------
Subject: 123)  Can I have two applications draw to the same window?

    Yes. The X server, primarily, assigns IDs to windows and other
resources, and any application that knows the ID can manipulate the resource.
    The problem you face is how to disseminate the window ID to multiple
applications. A simple way to handle this (and which solves the problem of the
applications' running on different machines) is in the first application to
create a specially-named property on the root-window and put the window ID into
it. The second application then retrieves the property, whose name it also
knows, and then can draw whatever it wants into the window.
    [Note: this scheme works iff there is only one instance of the first
application running, and the scheme is subject to the limitations mentioned
in the Question about using window IDs on remote displays.]
    Note also that you will still need to coordinate any higher-level
cooperation among your applications.
    Note also that two processes can share a window but should not try to
use the same server connection. If one process is a child of the other, it
should close down the connection to the server and open its own connection.

[mostly courtesy Phil Karlton ([e-mail]) 6/90]

----------------------------------------------------------------------
Subject: 124)  How do I keep a window from being resized by the user?

    Resizing the window is done through the window manager; window managers
can pay attention to the size hints your application places on the window, but
there is no guarantee that the window manager will listen. You can try setting
the minimum and maximum size hints to your target size and hope for the best.
[1/91]

----------------------------------------------------------------------
Subject: 125)  How do I render rotated text?

    Xlib intentionally does not provide such sophisticated graphics
capabilities, leaving them up to server-extensions or clients-side graphics
libraries.
    Your only choice, if you want to stay within the core X protocol, is to
render the text into a pixmap, read it back via XGetImage(), rotate it "by hand"
with whatever matrices you want, and put it back to the server via XPutImage();
more specifically:
    1) create a bitmap B and write your text to it.
    2) create an XYBitmap image I from B (via XGetImage).
    3) create an XYBitmap Image I2 big enough to handle the transformation.
    4) for each x,y in I2, I2(x,y) = I(a,b) where
        a = x * cos(theta) - y * sin(theta)
        b = x * sin(theta) + y * cos(theta)
    5) render I2
    Note that you should be careful how you implement this not to lose
bits; an algorithm based on shear transformations may in fact be better.
    The high-level server-extensions and graphics packages available for X
also permit rendering of rotated text: Display PostScript, PEX, PHIGS, and GKS,
although most are not capable of arbitrary rotation and probably do not use the
same fonts that would be found on a printer.
    In addition, if you have enough access to the server to install a font
on it, you can create a font which consists of letters rotated at some
predefined angle. Your application can then itself figure out placement of each
glyph.

[courtesy der Mouse ([e-mail]), Eric Taylor
([e-mail]), and Ken Lee ([e-mail]), 11/90;
Liam Quin ([e-mail]), 12/90]

    InterViews (C++ UI toolkit, in the X contrib software) has support for
rendering rotated fonts in X.  It could be one source of example code.
[Brian R. Smith ([e-mail]), 3/91]

----------------------------------------------------------------------
Subject: 126)  Why can't my program get a standard colormap?
I have an image-processing program which uses XGetRGBColormap() to get the
standard colormap, but it doesn't work.

    XGetRGBColormap() when used with the property XA_RGB_DEFAULT_MAP does
not create a standard colormap -- it just returns one if one already exists.
Use xstdcmap or do what it does in order to create the standard colormap first.

[1/91; from der Mouse ([e-mail])]

----------------------------------------------------------------------
Subject: 127)  What is the X Registry? (How do I reserve names?)

    There are places in the X Toolkit, in applications, and in the X
protocol that define and use string names. The context is such that conflicts
are possible if different components use the same name for different things.
    The MIT X Consortium maintains a registry of names in these domains:
orgainization names, selection names, selection targets, resource types,
application classes, and class extension record types; and several others.
    The list as of 1/90 is in the directory mit/doc/Registry on the R4 tape.
    To register names (first come, first served) or to ask questions send
to [e-mail]; be sure to include a postal address for
confirmation.

[11/90; condensed from Asente/Swick Appendix H]