X - a portable, network-transparent window system


   The  X  Window System is a network transparent window system which runs
   on a wide range of computing  and  graphics  machines.   It  should  be
   relatively  straightforward  to  build  the  X.Org  Foundation software
   distribution on most ANSI C and POSIX  compliant  systems.   Commercial
   implementations are also available for a wide range of platforms.

   The  X.Org  Foundation  requests  that the following names be used when
   referring to this software:

                               X Window System
                                X Version 11
                         X Window System, Version 11

   X Window System is a trademark of The Open Group.


   X Window System servers run on computers  with  bitmap  displays.   The
   server  distributes  user  input  to  and  accepts output requests from
   various client programs through a  variety  of  different  interprocess
   communication  channels.   Although  the  most  common  case is for the
   client programs to be running  on  the  same  machine  as  the  server,
   clients  can  be  run  transparently  from  other  machines  (including
   machines with different architectures and operating systems) as well.

   X supports overlapping hierarchical subwindows and  text  and  graphics
   operations,  on  both  monochrome  and  color  displays.   For  a  full
   explanation of the functions that are  available,  see  the  Xlib  -  C
   Language   X   Interface   manual,   the   X   Window  System  Protocol
   specification, the X Toolkit Intrinsics - C Language Interface  manual,
   and various toolkit documents.

   The number of programs that use X is quite large.  Programs provided in
   the core X.Org Foundation distribution include:  a  terminal  emulator,
   xterm;  a  window  manager,  twm;  a  display  manager,  xdm; a console
   redirect program, xconsole; a mail interface,  xmh;  a  bitmap  editor,
   bitmap;  resource  listing/manipulation  tools, appres, editres; access
   control programs, xauth, xhost, and iceauth;  user  preference  setting
   programs,  xrdb, xcmsdb, xset, xsetroot, xstdcmap, and xmodmap; clocks,
   xclock and  oclock;  a  font  displayer,  xfd;  utilities  for  listing
   information  about  fonts,  windows,  and displays, xlsfonts, xwininfo,
   xlsclients, xdpyinfo, xlsatoms, and xprop;  screen  image  manipulation
   utilities,  xwd,  xwud,  and  xmag;  a performance measurement utility,
   x11perf;  a  font  compiler,  bdftopcf;  a  font  server  and   related
   utilities,  xfs,  fsinfo,  fslsfonts,  fstobdf;  a  display  server and
   related  utilities,  Xserver,  rgb,  mkfontdir;  a  clipboard  manager,
   xclipboard;   keyboard  description  compiler  and  related  utilities,
   xkbcomp, setxkbmap xkbprint, xkbbell, xkbevd, xkbvleds, and xkbwatch; a
   utility to terminate clients, xkill; a firewall security proxy, xfwp; a
   proxy manager to control them, proxymngr; a utility  to  find  proxies,
   xfindproxy;  web  browser  plug-ins, libxrx.so and libxrxnest.so; an RX
   MIME-type helper program, xrx; and a utility to cause part  or  all  of
   the screen to be redrawn, xrefresh.

   Many  other  utilities,  window  managers,  games,  toolkits,  etc. are
   included  as  user-contributed  software  in   the   X.Org   Foundation
   distribution,  or  are  available  on  the  Internet.   See  your  site
   administrator for details.


   There are two main ways of getting the X server and an initial  set  of
   client  applications  started.   The  particular method used depends on
   what operating system you are running and whether or not you use  other
   window systems in addition to X.

   Display Manager
           If you want to always have X running on your display, your site
           administrator can set your machine up to use a Display  Manager
           such as xdm, gdm, or kdm.  This program is typically started by
           the system at boot time and takes care of  keeping  the  server
           running and getting users logged in.  If you are running one of
           these display managers, you will normally see a window  on  the
           screen  welcoming  you  to the system and asking for your login
           information.  Simply type them in as  you  would  at  a  normal
           terminal.   If  you  make  a  mistake, the display manager will
           display an error message and ask you to try again.   After  you
           have  successfully logged in, the display manager will start up
           your X environment.  The documentation for the display  manager
           you use can provide more details.

   xinit (run manually from the shell)
           Sites  that support more than one window system might choose to
           use the xinit program for starting X manually.  If this is true
           for  your  machine,  your site administrator will probably have
           provided a program named "x11", "startx", or "xstart" that will
           do  site-specific  initialization  (such  as loading convenient
           default resources,  running  a  window  manager,  displaying  a
           clock,  and starting several terminal emulators) in a nice way.
           If not, you can build such a script using  the  xinit  program.
           This  utility  simply  runs one user-specified program to start
           the server, runs another to start up any desired  clients,  and
           then  waits  for either to finish.  Since either or both of the
           user-specified programs may  be  a  shell  script,  this  gives
           substantial  flexibility  at  the  expense of a nice interface.
           For this reason, xinit is not intended for end users.


   From the user's perspective, every X server has a display name  of  the


   This  information is used by the application to determine how it should
   connect to the server and which screen it should  use  by  default  (on
   displays with multiple monitors):

           The  hostname  specifies  the  name of the machine to which the
           display is physically connected.  If the hostname is not given,
           the most efficient way of communicating to a server on the same
           machine will be used.

           The phrase "display" is usually used to refer to  a  collection
           of monitors that share a common set of input devices (keyboard,
           mouse, tablet, etc.).  Most workstations tend to only have  one
           display.   Larger, multi-user systems, however, frequently have
           several displays so that more than  one  person  can  be  doing
           graphics  work  at once.  To avoid confusion, each display on a
           machine is assigned a display number (beginning at 0) when  the
           X  server for that display is started.  The display number must
           always be given in a display name.

           Some displays share their  input  devices  among  two  or  more
           monitors.   These may be configured as a single logical screen,
           which allows windows to move across screens, or  as  individual
           screens,  each  with  their  own set of windows.  If configured
           such that each monitor has its own set of windows, each  screen
           is  assigned a screen number (beginning at 0) when the X server
           for that display is started.   If  the  screen  number  is  not
           given, screen 0 will be used.

   On  POSIX  systems,  the default display name is stored in your DISPLAY
   environment variable.  This variable is set automatically by the  xterm
   terminal  emulator.   However,  when  you log into another machine on a
   network, you may need to set DISPLAY by hand to point to your  display.
   For example,

       % setenv DISPLAY myws:0
       $ DISPLAY=myws:0; export DISPLAY

   The  ssh program can be used to start an X program on a remote machine;
   it automatically sets the DISPLAY variable correctly.

   Finally, most X programs accept  a  command  line  option  of  -display
   displayname  to  temporarily override the contents of DISPLAY.  This is
   most commonly used to pop windows on another person's screen or as part
   of  a  "remote  shell"  command to start an xterm pointing back to your
   display.  For example,

       % xeyes -display joesws:0 -geometry 1000x1000+0+0
       % rsh big xterm -display myws:0 -ls </dev/null &

   X  servers  listen  for  connections  on   a   variety   of   different
   communications  channels  (network  byte streams, shared memory, etc.).
   Since there can be more than one way of contacting a given server,  The
   hostname  part  of  the  display  name is used to determine the type of
   channel (also  called  a  transport  layer)  to  be  used.   X  servers
   generally support the following types of connections:

           The  hostname  part  of  the  display  name should be the empty
           string.  For example:  :0, :1, and :0.1.   The  most  efficient
           local transport will be chosen.

           The  hostname  part  of  the  display name should be the server
           machine's  hostname  or  IP  address.   Full  Internet   names,
           abbreviated  names,  IPv4 addresses, and IPv6 addresses are all
           allowed.     For    example:    x.org:0,    expo:0,    [::1]:0,
 , bigmachine:1, and hydra:0.1.


   An  X  server  can  use  several  types  of access control.  Mechanisms
   provided in Release 7 are:

   Host Access           Simple host-based access control.
   MIT-MAGIC-COOKIE-1    Shared plain-text "cookies".
   XDM-AUTHORIZATION-1   Secure DES based private-keys.
   SUN-DES-1             Based on Sun's secure rpc system.
   Server Interpreted    Server-dependent methods of access control

   Xdm  initializes  access  control  for  the  server  and  also   places
   authorization information in a file accessible to the user.

   Normally,  the list of hosts from which connections are always accepted
   should be empty, so that only clients with  are  explicitly  authorized
   can  connect  to  the  display.   When you add entries to the host list
   (with xhost), the  server  no  longer  performs  any  authorization  on
   connections from those machines.  Be careful with this.

   The  file  from which Xlib extracts authorization data can be specified
   with the environment variable XAUTHORITY,  and  defaults  to  the  file
   .Xauthority in the home directory.  Xdm uses $HOME/.Xauthority and will
   create it or merge in authorization records if it already exists when a
   user logs in.

   If  you  use  several machines and share a common home directory across
   all of the machines by means of a network file system, you never really
   have  to  worry  about  authorization  files,  the  system  should work
   correctly by  default.   Otherwise,  as  the  authorization  files  are
   machine-independent,  you  can simply copy the files to share them.  To
   manage authorization files, use xauth.   This  program  allows  you  to
   extract  records and insert them into other files.  Using this, you can
   send authorization to remote machines when you  login,  if  the  remote
   machine does not share a common home directory with your local machine.
   Note  that  authorization  information  transmitted  ``in  the  clear''
   through  a network file system or using ftp or rcp can be ``stolen'' by
   a network eavesdropper, and as such may enable unauthorized access.  In
   many  environments,  this level of security is not a concern, but if it
   is,  you  need  to  know  the  exact  semantics   of   the   particular
   authorization data to know if this is actually a problem.

   For  more  information  on  access control, see the Xsecurity(7) manual


   One of the advantages of using  window  systems  instead  of  hardwired
   terminals  is  that  applications  don't  have  to  be  restricted to a
   particular size or location on the  screen.   Although  the  layout  of
   windows  on a display is controlled by the window manager that the user
   is running (described below), most X programs  accept  a  command  line
   argument  of  the  form  -geometry WIDTHxHEIGHT+XOFF+YOFF (where WIDTH,
   HEIGHT, XOFF, and YOFF are numbers) for specifying a preferred size and
   location for this application's main window.

   The  WIDTH  and  HEIGHT parts of the geometry specification are usually
   measured in either pixels or characters, depending on the  application.
   The  XOFF and YOFF parts are measured in pixels and are used to specify
   the distance of the window from the left or right and  top  and  bottom
   edges  of the screen, respectively.  Both types of offsets are measured
   from the indicated edge of the screen to the corresponding edge of  the
   window.  The X offset may be specified in the following ways:

   +XOFF   The left edge of the window is to be placed XOFF pixels in from
           the left edge of the screen (i.e.,  the  X  coordinate  of  the
           window's  origin will be XOFF).  XOFF may be negative, in which
           case the window's left edge will be off the screen.

   -XOFF   The right edge of the window is to be  placed  XOFF  pixels  in
           from  the  right  edge of the screen.  XOFF may be negative, in
           which case the window's right edge will be off the screen.

   The Y offset has similar meanings:

   +YOFF   The top edge of the window is to be YOFF pixels below  the  top
           edge  of  the  screen  (i.e.,  the Y coordinate of the window's
           origin will be YOFF).  YOFF may be negative, in which case  the
           window's top edge will be off the screen.

   -YOFF   The  bottom  edge  of the window is to be YOFF pixels above the
           bottom edge of the screen.  YOFF may be negative, in which case
           the window's bottom edge will be off the screen.

   Offsets  must  be  given  as pairs; in other words, in order to specify
   either XOFF or YOFF both must be present.  Windows can be placed in the
   four corners of the screen using the following specifications:

   +0+0    upper left hand corner.

   -0+0    upper right hand corner.

   -0-0    lower right hand corner.

   +0-0    lower left hand corner.

   In the following examples, a terminal emulator is placed in roughly the
   center of the screen and a load average monitor, mailbox, and clock are
   placed in the upper right hand corner:

       xterm -fn 6x10 -geometry 80x24+30+200 &
       xclock -geometry 48x48-0+0 &
       xload -geometry 48x48-96+0 &
       xbiff -geometry 48x48-48+0 &


   The  layout  of windows on the screen is controlled by special programs
   called window managers.   Although  many  window  managers  will  honor
   geometry  specifications  as  given,  others  may choose to ignore them
   (requiring the user to explicitly  draw  the  window's  region  on  the
   screen with the pointer, for example).

   Since  window  managers are regular (albeit complex) client programs, a
   variety  of  different  user  interfaces  can  be  built.   The   X.Org
   Foundation  distribution  comes  with  a window manager named twm which
   supports overlapping windows, popup menus, point-and-click or click-to-
   type  input  models,  title  bars,  nice icons (and an icon manager for
   those who don't like separate icon windows).

   See the user-contributed software in the X.Org Foundation  distribution
   for other popular window managers.


   Collections  of  characters  for  displaying  text and symbols in X are
   known as fonts.  A font typically contains images that share  a  common
   appearance  and  look  nice  together  (for  example,  a  single  size,
   boldness, slant, and character set).  Similarly, collections  of  fonts
   that are based on a common type face (the variations are usually called
   roman, bold, italic, bold italic, oblique, and bold oblique) are called

   Fonts  come  in  various  sizes.  The X server supports scalable fonts,
   meaning it is possible to create a font of arbitrary size from a single
   source  for  the  font.  The server supports scaling from outline fonts
   and  bitmap  fonts.   Scaling  from  outline  fonts  usually   produces
   significantly better results than scaling from bitmap fonts.

   An   X  server  can  obtain  fonts  from  individual  files  stored  in
   directories in the file system, or from one or more  font  servers,  or
   from  a  mixtures  of directories and font servers.  The list of places
   the server looks when trying to find a font is controlled by  its  font
   path.  Although most installations will choose to have the server start
   up with all of the commonly used font directories in the font path, the
   font  path  can be changed at any time with the xset program.  However,
   it is important to  remember  that  the  directory  names  are  on  the
   server's machine, not on the application's.

   Bitmap  font  files  are  usually  created  by compiling a textual font
   description into binary  form,  using  bdftopcf.   Font  databases  are
   created  by  running  the mkfontdir program in the directory containing
   the source or compiled versions of the fonts.  Whenever fonts are added
   to  a  directory, mkfontdir should be rerun so that the server can find
   the new fonts.  To make the server reread the font database, reset  the
   font  path  with  the  xset  program.   For example, to add a font to a
   private directory, the following commands could be used:

       % cp newfont.pcf ~/myfonts
       % mkfontdir ~/myfonts
       % xset fp rehash

   The xfontsel and xlsfonts programs can be used to  browse  through  the
   fonts available on a server.  Font names tend to be fairly long as they
   contain all of the information needed to uniquely  identify  individual
   fonts.   However,  the  X server supports wildcarding of font names, so
   the full specification


   might be abbreviated as:


   Because the shell also has special meanings for  *  and  ?,  wildcarded
   font names should be quoted:

       % xlsfonts -fn '-*-courier-medium-r-normal--*-100-*-*-*-*-*-*'

   The  xlsfonts program can be used to list all of the fonts that match a
   given pattern.  With no arguments, it lists all available fonts.   This
   will  usually  list the same font at many different sizes.  To see just
   the base scalable font names, try using one of the following patterns:


   To convert one of the resulting names into a font at a  specific  size,
   replace  one  of  the  first two zeros with a nonzero value.  The field
   containing the first zero is for the pixel  size;  replace  it  with  a
   specific  height in pixels to name a font at that size.  Alternatively,
   the field containing the second zero is for the point size; replace  it
   with  a  specific size in decipoints (there are 722.7 decipoints to the
   inch) to name a font at that size.  The last zero is an  average  width
   field,  measured  in tenths of pixels; some servers will anamorphically
   scale if this value is specified.


   One of the following forms can be used  to  name  a  font  server  that
   accepts TCP connections:


   The  hostname  specifies  the  name (or decimal numeric address) of the
   machine on which the font server is running.  The port is  the  decimal
   TCP  port  on  which the font server is listening for connections.  The
   cataloguelist specifies a list  of  catalogue  names,  with  '+'  as  a

   Examples: tcp/x.org:7100, tcp/


   Most  applications provide ways of tailoring (usually through resources
   or command line arguments) the colors of various elements in  the  text
   and  graphics  they  display.   A  color  can be specified either by an
   abstract color name,  or  by  a  numerical  color  specification.   The
   numerical specification can identify a color in either device-dependent
   (RGB) or device-independent terms.  Color strings are case-insensitive.

   X supports the use of abstract color names, for example, "red", "blue".
   A  value  for  this  abstract name is obtained by searching one or more
   color name databases.  Xlib first searches  zero  or  more  client-side
   databases;  the  number,  location,  and  content of these databases is
   implementation dependent.  If the name  is  not  found,  the  color  is
   looked  up  in the X server's database.  The text form of this database
   is commonly stored in the file usr/share/X11/rgb.txt.

   A numerical color specification consists of a color space  name  and  a
   set of values in the following syntax:


   An  RGB Device specification is identified by the prefix "rgb:" and has
   the following syntax:


           <red>, <green>, <blue> := h | hh | hhh | hhhh
           h := single hexadecimal digits

   Note that h indicates the value scaled in 4 bits, hh the  value  scaled
   in  8  bits, hhh the value scaled in 12 bits, and hhhh the value scaled
   in 16 bits, respectively.  These values are passed directly  to  the  X
   server, and are assumed to be gamma corrected.

   The eight primary colors can be represented as:

                        black     rgb:0/0/0
                        red       rgb:ffff/0/0
                        green     rgb:0/ffff/0
                        blue      rgb:0/0/ffff
                        yellow    rgb:ffff/ffff/0
                        magenta   rgb:ffff/0/ffff
                        cyan      rgb:0/ffff/ffff
                        white     rgb:ffff/ffff/ffff

   For   backward  compatibility,  an  older  syntax  for  RGB  Device  is
   supported, but its continued use is not encouraged.  The syntax  is  an
   initial  sharp  sign  character followed by a numeric specification, in
   one of the following formats:

                       #RGB            (4 bits each)
                       #RRGGBB         (8 bits each)
                       #RRRGGGBBB      (12 bits each)
                       #RRRRGGGGBBBB   (16 bits each)

   The R, G, and B represent single hexadecimal digits.  When  fewer  than
   16 bits each are specified, they represent the most-significant bits of
   the value (unlike the "rgb:" syntax, in which values are scaled).   For
   example, #3a7 is the same as #3000a0007000.

   An  RGB intensity specification is identified by the prefix "rgbi:" and
   has the following syntax:


   The red, green, and blue are floating point values between 0.0 and 1.0,
   inclusive.  They represent linear intensity values, with 1.0 indicating
   full intensity, 0.5 half intensity, and so on.  These  values  will  be
   gamma  corrected  by Xlib before being sent to the X server.  The input
   format for these values is  an  optional  sign,  a  string  of  numbers
   possibly  containing  a  decimal  point, and an optional exponent field
   containing an E or e followed by a possibly signed integer string.

   The  standard  device-independent  string   specifications   have   the
   following syntax:

                   CIEXYZ:<X>/<Y>/<Z>   (none, 1, none)
                   CIEuvY:<u>/<v>/<Y>   (~.6, ~.6, 1)
                   CIExyY:<x>/<y>/<Y>   (~.75, ~.85, 1)
                   CIELab:<L>/<a>/<b>   (100, none, none)
                   CIELuv:<L>/<u>/<v>   (100, none, none)
                   TekHVC:<H>/<V>/<C>   (360, 100, 100)

   All  of  the  values  (C, H, V, X, Y, Z, a, b, u, v, y, x) are floating
   point values.  Some of the values are constrained to  be  between  zero
   and  some upper bound; the upper bounds are given in parentheses above.
   The syntax for these values is an optional '+' or '-' sign, a string of
   digits  possibly  containing  a decimal point, and an optional exponent
   field consisting of an 'E' or 'e' followed by an optional  '+'  or  '-'
   followed by a string of digits.

   For  more  information  on  device  independent  color,  see  the  Xlib
   reference manual.


   The X keyboard model is broken into two layers:  server-specific  codes
   (called  keycodes)  which  represent  the  physical  keys,  and server-
   independent symbols (called keysyms) which  represent  the  letters  or
   words  that  appear on the keys.  Two tables are kept in the server for
   converting keycodes to keysyms:

   modifier list
           Some keys (such as Shift, Control, and Caps Lock) are known  as
           modifier  and  are  used  to  select different symbols that are
           attached to a single key (such as Shift-a generates  a  capital
           A, and Control-l generates a control character ^L).  The server
           keeps a list of keycodes corresponding to the various  modifier
           keys.   Whenever  a  key  is  pressed  or  released, the server
           generates an event that contains the keycode of  the  indicated
           key as well as a mask that specifies which of the modifier keys
           are currently pressed.   Most  servers  set  up  this  list  to
           initially  contain  the  various shift, control, and shift lock
           keys on the keyboard.

   keymap table
           Applications translate event keycodes and modifier  masks  into
           keysyms  using  a  keysym table which contains one row for each
           keycode and one column for various modifier states.  This table
           is initialized by the server to correspond to normal typewriter
           conventions.   The  exact  semantics  of  how  the   table   is
           interpreted  to  produce  keysyms  depends  on  the  particular
           program, libraries, and language input  method  used,  but  the
           following  conventions  for  the first four keysyms in each row
           are generally adhered to:

   The first four elements of the  list  are  split  into  two  groups  of
   keysyms.   Group  1  contains  the  first  and  second keysyms; Group 2
   contains the third and fourth keysyms.  Within each group, if the first
   element  is alphabetic and the the second element is the special keysym
   NoSymbol, then the group is treated as equivalent to a group  in  which
   the first element is the lowercase letter and the second element is the
   uppercase letter.

   Switching between groups is controlled by the keysym named MODE SWITCH,
   by  attaching that keysym to some key and attaching that key to any one
   of the modifiers Mod1  through  Mod5.   This  modifier  is  called  the
   ``group  modifier.''   Group  1 is used when the group modifier is off,
   and Group 2 is used when the group modifier is on.

   Within a group, the modifier state determines which keysym to use.  The
   first  keysym  is  used when the Shift and Lock modifiers are off.  The
   second keysym is used when the Shift modifier  is  on,  when  the  Lock
   modifier  is  on and the second keysym is uppercase alphabetic, or when
   the Lock modifier is on and is interpreted  as  ShiftLock.   Otherwise,
   when  the Lock modifier is on and is interpreted as CapsLock, the state
   of the Shift modifier is applied first to select a keysym; but if  that
   keysym is lowercase alphabetic, then the corresponding uppercase keysym
   is used instead.


   Most X programs attempt to use the same names for command line  options
   and  arguments.  All applications written with the X Toolkit Intrinsics
   automatically accept the following options:

   -display display
           This option specifies the name of the X server to use.

   -geometry geometry
           This option specifies the initial  size  and  location  of  the

   -bg color, -background color
           Either  option  specifies  the  color  to  use  for  the window

   -bd color, -bordercolor color
           Either option specifies the color to use for the window border.

   -bw number, -borderwidth number
           Either option specifies the  width  in  pixels  of  the  window

   -fg color, -foreground color
           Either option specifies the color to use for text or graphics.

   -fn font, -font font
           Either option specifies the font to use for displaying text.

           This  option  indicates  that  the  user  would prefer that the
           application's windows  initially  not  be  visible  as  if  the
           windows  had  be  immediately  iconified  by  the user.  Window
           managers may choose not to honor the application's request.

           This option specifies the name under which  resources  for  the
           application  should  be  found.  This option is useful in shell
           aliases to distinguish between invocations of  an  application,
           without  resorting  to  creating  links to alter the executable
           file name.

   -rv, -reverse
           Either  option  indicates  that  the  program  should  simulate
           reverse video if possible, often by swapping the foreground and
           background colors.  Not all programs honor this or implement it
           correctly.  It is usually only used on monochrome displays.

           This  option  indicates  that  the  program should not simulate
           reverse video.  This is used to  override  any  defaults  since
           reverse video doesn't always work properly.

           This  option specifies the timeout in milliseconds within which
           two communicating applications must respond to one another  for
           a selection request.

           This  option  indicates that requests to the X server should be
           sent synchronously,  instead  of  asynchronously.   Since  Xlib
           normally   buffers  requests  to  the  server,  errors  do  not
           necessarily get reported immediately after  they  occur.   This
           option  turns  off the buffering so that the application can be
           debugged.  It should never be used with a working program.

   -title string
           This option specifies the title to be  used  for  this  window.
           This  information  is  sometimes  used  by  a window manager to
           provide some sort of header identifying the window.

   -xnllanguage language[_territory][.codeset]
           This option specifies the language, territory, and codeset  for
           use in resolving resource and other filenames.

   -xrm resourcestring
           This option specifies a resource name and value to override any
           defaults.  It is also very useful for  setting  resources  that
           don't have explicit command line arguments.


   To make the tailoring of applications to personal preferences easier, X
   provides a mechanism for storing default values for  program  resources
   (e.g.  background  color,  window title, etc.) that is used by programs
   that use toolkits based on the  X  Toolkit  Intrinsics  library  libXt.
   (Programs using the common Gtk+ and Qt toolkits use other configuration
   mechanisms.)  Resources are specified as strings that are read in  from
   various  places  when  an  application  is run.  Program components are
   named in a hierarchical  fashion,  with  each  node  in  the  hierarchy
   identified  by  a  class and an instance name.  At the top level is the
   class and instance name of the application itself.  By convention,  the
   class name of the application is the same as the program name, but with
   the first letter capitalized  (e.g.  Bitmap  or  Emacs)  although  some
   programs  that  begin  with the letter ``x'' also capitalize the second
   letter for historical reasons.

   The precise syntax for resources is:

   ResourceLine    =       Comment | IncludeFile | ResourceSpec | <empty line>
   Comment         =       "!" {<any character except null or newline>}
   IncludeFile     =       "#" WhiteSpace "include" WhiteSpace FileName WhiteSpace
   FileName        =       <valid filename for operating system>
   ResourceSpec    =       WhiteSpace ResourceName WhiteSpace ":" WhiteSpace Value
   ResourceName    =       [Binding] {Component Binding} ComponentName
   Binding         =       "." | "*"
   WhiteSpace      =       {<space> | <horizontal tab>}
   Component       =       "?" | ComponentName
   ComponentName   =       NameChar {NameChar}
   NameChar        =       "a"-"z" | "A"-"Z" | "0"-"9" | "_" | "-"
   Value           =       {<any character except null or unescaped newline>}

   Elements separated by vertical bar (|) are alternatives.  Curly  braces
   ({...})  indicate  zero  or  more repetitions of the enclosed elements.
   Square brackets ([...]) indicate that the enclosed element is optional.
   Quotes ("...") are used around literal characters.

   IncludeFile  lines  are  interpreted  by  replacing  the  line with the
   contents of  the  specified  file.   The  word  "include"  must  be  in
   lowercase.   The  filename  is interpreted relative to the directory of
   the file in which  the  line  occurs  (for  example,  if  the  filename
   contains no directory or contains a relative directory specification).

   If a ResourceName contains a contiguous sequence of two or more Binding
   characters, the sequence will be replaced with single "." character  if
   the  sequence contains only "." characters, otherwise the sequence will
   be replaced with a single "*" character.

   A resource database never contains more than  one  entry  for  a  given
   ResourceName.  If a resource file contains multiple lines with the same
   ResourceName, the last line in the file is used.

   Any whitespace character before  or  after  the  name  or  colon  in  a
   ResourceSpec  are  ignored.  To allow a Value to begin with whitespace,
   the two-character sequence ``\space'' (backslash followed by space)  is
   recognized  and  replaced  by  a space character, and the two-character
   sequence ``\tab'' (backslash followed by horizontal tab) is  recognized
   and  replaced  by  a  horizontal  tab  character.   To allow a Value to
   contain embedded newline characters, the two-character sequence  ``\n''
   is recognized and replaced by a newline character.  To allow a Value to
   be broken across multiple lines  in  a  text  file,  the  two-character
   sequence ``\newline'' (backslash followed by newline) is recognized and
   removed from  the  value.   To  allow  a  Value  to  contain  arbitrary
   character  codes, the four-character sequence ``\nnn'', where each n is
   a digit character in  the  range  of  ``0''-``7'',  is  recognized  and
   replaced  with a single byte that contains the octal value specified by
   the sequence.  Finally, the two-character sequence ``\\'' is recognized
   and replaced with a single backslash.

   When  an  application looks for the value of a resource, it specifies a
   complete path in the hierarchy, with both  class  and  instance  names.
   However,   resource  values  are  usually  given  with  only  partially
   specified names and classes, using  pattern  matching  constructs.   An
   asterisk  (*) is a loose binding and is used to represent any number of
   intervening components, including  none.   A  period  (.)  is  a  tight
   binding  and  is  used  to separate immediately adjacent components.  A
   question mark (?) is used to match any single component name or  class.
   A  database  entry  cannot  end in a loose binding; the final component
   (which cannot be "?") must be specified.  The lookup algorithm searches
   the  resource database for the entry that most closely matches (is most
   specific for) the full name and class being queried.   When  more  than
   one  database  entry  matches the full name and class, precedence rules
   are used to select just one.

   The full name and class are scanned from left to  right  (from  highest
   level  in  the  hierarchy to lowest), one component at a time.  At each
   level, the corresponding component  and/or  binding  of  each  matching
   entry  is  determined,  and  these matching components and bindings are
   compared according to precedence rules.  Each of the rules  is  applied
   at  each level, before moving to the next level, until a rule selects a
   single entry over all others.  The rules (in order of precedence) are:

   1.   An entry that contains a matching component (whether name,  class,
        or  "?")  takes precedence over entries that elide the level (that
        is, entries that match the level in a loose binding).

   2.   An entry with a matching name takes precedence over  both  entries
        with  a matching class and entries that match using "?".  An entry
        with a matching class takes precedence  over  entries  that  match
        using "?".

   3.   An entry preceded by a tight binding takes precedence over entries
        preceded by a loose binding.

   Programs based on the X Toolkit Intrinsics obtain  resources  from  the
   following  sources (other programs usually support some subset of these

   RESOURCE_MANAGER root window property
           Any global resources that should be available to clients on all
           machines  should  be stored in the RESOURCE_MANAGER property on
           the root window of the first screen  using  the  xrdb  program.
           This  is  frequently  taken  care  of when the user starts up X
           through the display manager or xinit.

   SCREEN_RESOURCES root window property
           Any resources specific to a given  screen  (e.g.  colors)  that
           should be available to clients on all machines should be stored
           in the SCREEN_RESOURCES property on the  root  window  of  that
           screen.  The xrdb program will sort resources automatically and
           place  them  in  RESOURCE_MANAGER   or   SCREEN_RESOURCES,   as

   application-specific files
           Directories     named     by     the    environment    variable
           XUSERFILESEARCHPATH or  the  environment  variable  XAPPLRESDIR
           (which  names  a  single directory and should end with a '/' on
           POSIX systems), plus directories in a standard  place  (usually
           under  /usr/share/X11/,  but  this  can  be overridden with the
           XFILESEARCHPATH environment  variable)  are  searched  for  for
           application-specific   resources.    For  example,  application
           default  resources  are  usually  kept  in  /usr/share/X11/app-
           defaults/.  See the X Toolkit Intrinsics - C Language Interface
           manual for details.

           Any user- and machine-specific resources may  be  specified  by
           setting  the XENVIRONMENT environment variable to the name of a
           resource file to  be  loaded  by  all  applications.   If  this
           variable is not defined, a file named $HOME/.Xdefaults-hostname
           is looked for instead, where hostname is the name of  the  host
           where the application is executing.

   -xrm resourcestring
           Resources  can  also  be  specified from the command line.  The
           resourcestring is a single resource name  and  value  as  shown
           above.  Note that if the string contains characters interpreted
           by the shell (e.g., asterisk), they must be quoted.  Any number
           of -xrm arguments may be given on the command line.

   Program  resources  are  organized  into groups called classes, so that
   collections  of  individual  resources  (each  of  which   are   called
   instances) can be set all at once.  By convention, the instance name of
   a resource begins with a lowercase letter and class name with an  upper
   case  letter.   Multiple word resources are concatenated with the first
   letter of the succeeding words capitalized.  Applications written  with
   the X Toolkit Intrinsics will have at least the following resources:

   background (class Background)
           This  resource  specifies  the  color  to  use  for  the window

   borderWidth (class BorderWidth)
           This resource specifies the  width  in  pixels  of  the  window

   borderColor (class BorderColor)
           This resource specifies the color to use for the window border.

   Most applications using the X Toolkit Intrinsics also have the resource
   foreground (class Foreground), specifying the color to use for text and
   graphics within the window.

   By combining class and instance specifications, application preferences
   can be set quickly and easily.  Users of color displays will frequently
   want  to  set Background and Foreground classes to particular defaults.
   Specific color instances such as text cursors can  then  be  overridden
   without having to define all of the related resources.  For example,

       bitmap*Dashed:  off
       XTerm*cursorColor:  gold
       XTerm*multiScroll:  on
       XTerm*jumpScroll:  on
       XTerm*reverseWrap:  on
       XTerm*curses:  on
       XTerm*Font:  6x10
       XTerm*scrollBar: on
       XTerm*scrollbar*thickness: 5
       XTerm*multiClickTime: 500
       XTerm*charClass:  33:48,37:48,45-47:48,64:48
       XTerm*cutNewline: off
       XTerm*cutToBeginningOfLine: off
       XTerm*titeInhibit:  on
       XTerm*ttyModes:  intr ^c erase ^? kill ^u
       XLoad*Background: gold
       XLoad*Foreground: red
       XLoad*highlight: black
       XLoad*borderWidth: 0
       emacs*Geometry:  80x65-0-0
       emacs*Background:  rgb:5b/76/86
       emacs*Foreground:  white
       emacs*Cursor:  white
       emacs*BorderColor:  white
       emacs*Font:  6x10
       xmag*geometry: -0-0
       xmag*borderColor:  white

   If  these  resources  were  stored in a file called .Xresources in your
   home directory, they could be added to any existing  resources  in  the
   server with the following command:

       % xrdb -merge $HOME/.Xresources

   This  is  frequently  how  user-friendly  startup  scripts  merge user-
   specific  defaults  into  any  site-wide  defaults.   All   sites   are
   encouraged   to   set  up  convenient  ways  of  automatically  loading
   resources. See the Xlib manual section Resource Manager  Functions  for
   more information.


          This  is  the only mandatory environment variable. It must point
          to an X server. See section "Display Names" above.

          This must point to a file that contains authorization data.  The
          default   is   $HOME/.Xauthority.  See  Xsecurity(7),  xauth(1),
          xdm(1), Xau(3).

          This must point to a file that contains authorization data.  The
          default is $HOME/.ICEauthority.

          The  first  non-empty  value  among  these  three determines the
          current locale's facet for character handling, and in particular
          the   default   text   encoding.  See  locale(7),  setlocale(3),

          This variable can  be  set  to  contain  additional  information
          important  for  the  current  locale  setting.  Typically set to
          @im=<input-method> to enable  a  particular  input  method.  See

          This  must point to a directory containing the locale.alias file
          and Compose and XLC_LOCALE file hierarchies for all locales. The
          default value is /usr/share/X11/locale.

          This must point to a file containing X resources. The default is
          $HOME/.Xdefaults-<hostname>.  Unlike  $HOME/.Xresources,  it  is
          consulted each time an X application starts.

          This  must  contain  a  colon  separated list of path templates,
          where libXt will search for resource files.  The  default  value
          consists of


          A path template is transformed to a pathname by substituting:

              %D => the implementation-specific default path
              %N => name (basename) being searched for
              %T => type (dirname) being searched for
              %S => suffix being searched for
              %C => value of the resource "customization"
                    (class "Customization")
              %L => the locale name
              %l => the locale's language (part before '_')
              %t => the locale's territory (part after '_` but before '.')
              %c => the locale's encoding (part after '.')

          This  must  contain  a  colon  separated list of path templates,
          where libXt will search for user dependent resource  files.  The
          default value is:


          $XAPPLRESDIR defaults to $HOME, see below.

          A path template is transformed to a pathname by substituting:

              %D => the implementation-specific default path
              %N => name (basename) being searched for
              %T => type (dirname) being searched for
              %S => suffix being searched for
              %C => value of the resource "customization"
                    (class "Customization")
              %L => the locale name
              %l => the locale's language (part before '_')
              %t => the locale's territory (part after '_` but before '.')
              %c => the locale's encoding (part after '.')

          This  must  point  to a base directory where the user stores the
          application dependent  resource  files.  The  default  value  is
          $HOME. Only used if XUSERFILESEARCHPATH is not set.

          This   must  point  to  a  file  containing  nonstandard  keysym
          definitions.  The default value is /usr/share/X11/XKeysymDB.

   XCMSDB This must point to a color name database file. The default value

          This  serves  as  main identifier for resources belonging to the
          program being executed. It defaults to the basename of  pathname
          of the program.

          Denotes  the  session  manager  to  which the application should
          connect. See xsm(1), rstart(1).

          Setting  this  variable  to  a  non-empty  value  disables   the
          XFree86-Bigfont  extension.  This  extension  is  a mechanism to
          reduce the memory consumption of big  fonts  by  use  of  shared


   These variables influence the X Keyboard Extension.


   The  following  is a collection of sample command lines for some of the
   more frequently used commands.  For more information  on  a  particular
   command, please refer to that command's manual page.

       %  xrdb $HOME/.Xresources
       %  xmodmap -e "keysym BackSpace = Delete"
       %  mkfontdir /usr/local/lib/X11/otherfonts
       %  xset fp+ /usr/local/lib/X11/otherfonts
       %  xmodmap $HOME/.keymap.km
       %  xsetroot -solid 'rgbi:.8/.8/.8'
       %  xset b 100 400 c 50 s 1800 r on
       %  xset q
       %  twm
       %  xmag
       %  xclock -geometry 48x48-0+0 -bg blue -fg white
       %  xeyes -geometry 48x48-48+0
       %  xbiff -update 20
       %  xlsfonts '*helvetica*'
       %  xwininfo -root
       %  xdpyinfo -display joesworkstation:0
       %  xhost -joesworkstation
       %  xrefresh
       %  xwd | xwud
       %  bitmap companylogo.bm 32x32
       %  xcalc -bg blue -fg magenta
       %  xterm -geometry 80x66-0-0 -name myxterm $*


   A  wide  variety of error messages are generated from various programs.
   The default error handler in Xlib (also used  by  many  toolkits)  uses
   standard  resources to construct diagnostic messages when errors occur.
   The   defaults   for   these   messages   are   usually    stored    in
   usr/share/X11/XErrorDB.   If  this  file is not present, error messages
   will be rather terse and cryptic.

   When the X Toolkit  Intrinsics  encounter  errors  converting  resource
   strings  to  the  appropriate  internal  format,  no error messages are
   usually printed.  This is convenient when it is desirable to  have  one
   set  of  resources  across  a  variety  of  displays  (e.g.  color  vs.
   monochrome, lots of fonts vs. very few, etc.),  although  it  can  pose
   problems  for  trying to determine why an application might be failing.
   This   behavior   can   be    overridden    by    the    setting    the
   StringConversionWarnings resource.

   To  force  the  X  Toolkit Intrinsics to always print string conversion
   error messages, the following resource should be  placed  in  the  file
   that  gets  loaded  onto  the  RESOURCE_MANAGER property using the xrdb
   program (frequently called .Xresources or  .Xres  in  the  user's  home

       *StringConversionWarnings: on

   To  have conversion messages printed for just a particular application,
   the appropriate instance name can be placed before the asterisk:

       xterm*StringConversionWarnings: on


   XOrgFoundation(7), XStandards(7), Xsecurity(7), appres(1), bdftopcf(1),
   bitmap(1), editres(1), fsinfo(1), fslsfonts(1), fstobdf(1), iceauth(1),
   imake(1), makedepend(1), mkfontdir(1), oclock(1), proxymngr(1), rgb(1),
   resize(1),  rstart(1),  smproxy(1), twm(1), x11perf(1), x11perfcomp(1),
   xauth(1), xclipboard(1),  xclock(1),  xcmsdb(1),  xconsole(1),  xdm(1),
   xdpyinfo(1),   xfd(1),   xfindproxy(1),   xfs(1),   xfwp(1),  xhost(1),
   xinit(1), xkbbell(1), xkbcomp(1), xkbevd(1), xkbprint(1),  xkbvleds(1),
   xkbwatch(1),    xkill(1),    xlogo(1),    xlsatoms(1),   xlsclients(1),
   xlsfonts(1),   xmag(1),   xmh(1),   xmodmap(1),   xprop(1),    xrdb(1),
   xrefresh(1),   xrx(1),   xset(1),   xsetroot(1),  xsm(1),  xstdcmap(1),
   xterm(1), xwd(1), xwininfo(1), xwud(1).  Xserver(1), Xorg(1),  Xdmx(1),
   Xephyr(1),  Xnest(1),  Xquartz(1), Xvfb(1), Xvnc(1), XWin(1).  Xlib - C
   Language X Interface, and X Toolkit Intrinsics - C Language Interface


   X Window System is a trademark of The Open Group.


   A cast of thousands, literally.  Releases 6.7 and later are brought  to
   you  by  the  X.Org  Foundation.  The names of all people who made it a
   reality will be found in the individual documents and source files.

   Releases 6.6 and 6.5 were done by The X.Org  Group.   Release  6.4  was
   done  by The X Project Team.  The Release 6.3 distribution was from The
   X Consortium, Inc.  The staff members at the X  Consortium  responsible
   for  that  release  were:  Donna  Converse  (emeritus),  Stephen Gildea
   (emeritus),  Kaleb  Keithley,  Matt  Landau   (emeritus),   Ralph   Mor
   (emeritus),  Janet O'Halloran, Bob Scheifler, Ralph Swick, Dave Wiggins
   (emeritus), and Reed Augliere.

   The X Window System standard was originally developed at the Laboratory
   for  Computer Science at the Massachusetts Institute of Technology, and
   all rights thereto were assigned to the  X  Consortium  on  January  1,
   1994.   X  Consortium, Inc. closed its doors on December 31, 1996.  All
   rights to the X Window System have been assigned to The Open Group.


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