X(7)                                                                      X(7)

       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 rela-
       tively straightforward to build the X.Org Foundation software distribu-
       tion on most ANSI C and POSIX compliant systems.  Commercial  implemen-
       tations 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:

       center; c.  X 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 vari-
       ous  client programs through a variety of different interprocess commu-
       nication 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  dif-
       ferent 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 explana-
       tion  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  redi-
       rect 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,  mkfont-
       dir; a clipboard manager, xclipboard; keyboard description compiler and
       related utilities, xkbcomp, setxkbmap xkbprint, xkbbell,  xkbevd,  xkb-
       vleds,  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 distribu-
       tion,  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 ter-
               minal.  If you make a mistake, the display manager will display
               an error message and ask you to try again.  After you have suc-
               cessfully  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  sub-
               stantial  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 moni-
               tors.   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  dis-
       playname 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  communica-
       tions  channels  (network  byte  streams,  shared memory, etc.).  Since
       there can be more than one way of contacting a given server, The  host-
       name  part of the display name is used to determine the type of channel
       (also called a transport layer) to be used.  X servers  generally  sup-
       port 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,  abbre-
               viated  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 pro-
       vided in Release 7 are:

       l  l.   Host   Access           Simple   host-based   access   control.
       MIT-MAGIC-COOKIE-1  Shared    plain-text   "cookies".    XDM-AUTHORIZA-
       TION-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  autho-
       rization 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  con-
       nections 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 cor-
       rectly 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 ter-
       minals 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 win-
               dow'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 ori-
               gin 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 geom-
       etry specifications as given, others may choose to ignore them (requir-
       ing 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  Founda-
       tion  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, bold-
       ness, 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 signifi-
       cantly better results than scaling from bitmap fonts.

       An  X  server can obtain fonts from individual files stored in directo-
       ries 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  cre-
       ated  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 spe-
       cific 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  sepa-

       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 numer-
       ical  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/X11R7/lib/X11/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:

       center;      l      l.       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 sup-
       ported, but its continued use is not encouraged.  The syntax is an ini-
       tial  sharp  sign character followed by a numeric specification, in one
       of the following formats:

       center; l l.  #RGB      (4 bits each) #RRGGBB   (8 bits each)  #RRRGGG-
       BBB     (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 possi-
       bly containing a decimal point, and an optional exponent field contain-
       ing an E or e followed by a possibly signed integer string.

       The  standard device-independent string specifications have the follow-
       ing syntax:

       center;     l     l.      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 refer-
       ence manual.

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

       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  inter-
               preted  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 gener-
               ally 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 con-
       tains 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 mod-
       ifier  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 win-

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

       -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 bor-

       -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  win-
               dows 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 nor-
               mally 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 pro-
               vide 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  iden-
       tified  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 con-
       tents 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  direc-
       tory 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 con-
       tain 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 speci-
       fied names and classes, using pattern matching constructs.  An asterisk
       (*) is a loose binding and is used to represent any number of interven-
       ing 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  appro-

       application-specific files
               Directories  named by the environment variable XUSERFILESEARCH-
               PATH 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/X11R7/lib/X11/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/X11R7/lib/X11/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  vari-
               able  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 back-

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

       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-spe-
       cific  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 cur-
              rent 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/X11R7/lib/X11/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 defini-
              tions.  The default value is /usr/X11R7/lib/X11/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 con-
              nect. 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 mem-


       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/X11R7/lib/X11/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 usu-
       ally 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 pro-
       gram (frequently called .Xresources or .Xres in the user's home  direc-

           *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),  xls-
       fonts(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 (emer-
       itus), 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.

                                 X Version 11                             X(7)

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