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       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

                                            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

       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, and; an  RX  MIME-
       type  helper program, xrx; and a utility to cause part or all of the screen to be redrawn,

       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 form:


       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:,   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
           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

       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 page.


       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

           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 families.

       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

           % 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 separator.

       Examples: tcp/, tcp/

       One of the following forms can  be  used  to  name  a  font  server  that  accepts  DECnet


       The  nodename  specifies the name (or decimal numeric address) of the machine on which the
       font server is running.  The objname is a normal,  case-insensitive  DECnet  object  name.
       The cataloguelist specifies a list of catalogue names, with '+' as a separator.

       Examples: DECnet/SRVNOD::FONT$DEFAULT, decnet/44.70::font$special/symbols.


       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

       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


               <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


       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

       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

       -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 window.

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

       -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 border.

       -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

       -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


       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 sources):

       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 appropriate.

       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 background.

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

       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


              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

              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), locale(1).

              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 XSetLocaleModifiers(3).

              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

              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 his application dependent
              resource files. The default value is $HOME. Only used if XUSERFILESEARCHPATH is not

              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 is

              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),

              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 memory.


       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/
           %  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 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.