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 relatively
       straightforward  to  build  the X.Org Foundation software distribution on
       most ANSI C and POSIX compliant systems.  Commercial implementations  are
       also available for a wide range of platforms.

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

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

       X Window System is a trademark of The Open Group.

       X Window System servers run  on  computers  with  bitmap  displays.   The
       server distributes user input to and accepts output requests from various
       client programs through a variety of different interprocess communication
       channels.  Although the most common case is for the client programs to be
       running on the same machine as the server, clients can be  run  transpar‐
       ently  from  other  machines (including machines with different architec‐
       tures 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 Tool‐
       kit Intrinsics - C Language Interface manual, and various  toolkit  docu‐

       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 pro‐
       grams, 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, xkb‐
       vleds, and xkbwatch; a utility to terminate clients,  xkill;  a  firewall
       security proxy, xfwp; a proxy manager to control them, proxymngr; a util‐
       ity to find proxies, xfindproxy;  web  browser  plug-ins,  libxrx.so  and
       libxrxnest.so;  an  RX  MIME-type  helper  program, xrx; and a utility to
       cause part or all of the screen to be redrawn, xrefresh.

       Many other utilities, window managers, games, toolkits, etc. are included
       as user-contributed software in the X.Org Foundation distribution, or are
       available on the Internet.  See your site administrator for details.
       There are two main ways of getting the X server and  an  initial  set  of
       client  applications started.  The particular method used depends on what
       operating system you are running and whether or not you use other  window
       systems in addition to X.

       Display Manager
               If  you  want to always have X running on your display, your site
               administrator can set your machine up to use  a  Display  Manager
               such  as  xdm, gdm, or kdm.  This program is typically started by
               the system at boot time and takes care of keeping the server run‐
               ning  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 termi‐
               nal.   If you make a mistake, the display manager will display an
               error message and ask you to try again.  After you have  success‐
               fully  logged  in, the display manager will start up your X envi‐
               ronment.  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 pro‐
               vided 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  flexibil‐
               ity  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  dis‐
       plays with multiple monitors):

               The  hostname specifies the name of the machine to which the dis‐
               play 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 graph‐
               ics  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

       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 net‐
       work, you may need to set DISPLAY by hand to point to your display.   For

           % 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 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  trans‐
               port will be chosen.

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

       An X server can use several types of access control.  Mechanisms provided
       in Release 7 are:
           Host Access                   Simple host-based access control.
           MIT-MAGIC-COOKIE-1            Shared plain-text "cookies".
           XDM-AUTHORIZATION-1           Secure DES based private-keys.
           SUN-DES-1                     Based on Sun's secure rpc system.
           Server Interpreted            Server-dependent methods of access control

       Xdm initializes access control for the server and also places  authoriza‐
       tion 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 care‐
       ful with this.

       The file from which Xlib extracts authorization  data  can  be  specified
       with  the environment variable XAUTHORITY, and defaults to the file .Xau‐
       thority in the home directory.  Xdm uses $HOME/.Xauthority and will  cre‐
       ate 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 informa‐
       tion  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 termi‐
       nals 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 dis‐
       play 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 mea‐
       sured  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 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 bot‐
               tom  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 geome‐
       try 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  over‐
       lapping windows, popup menus, point-and-click or click-to-type input mod‐
       els, 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 appear‐
       ance 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, mean‐
       ing 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

       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  direc‐
       tory,  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 direc‐
       tory, 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 con‐
       taining 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  spe‐
       cific 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 cata‐
       loguelist specifies a list of catalogue names, with '+' as a separator.

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

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


       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/sym‐

       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  speci‐
       fication can identify a color in either device-dependent (RGB) or device-
       independent terms.  Color strings are case-insensitive.

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

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


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


               <red>, <green>, <blue> := h | hh | hhh | hhhh
               h := single hexadecimal digits
       Note that h indicates the value scaled in 4 bits, hh the value scaled  in
       8  bits, hhh the value scaled in 12 bits, and hhhh the value scaled in 16
       bits, respectively.  These values are passed directly to  the  X  server,
       and are assumed to be gamma corrected.

       The eight primary colors can be represented as:

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

       For  backward compatibility, an older syntax for RGB Device is supported,
       but its continued use is not encouraged.  The syntax is an initial  sharp
       sign character followed by a numeric specification, in one of the follow‐
       ing 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  exam‐
       ple, #3a7 is the same as #3000a0007000.

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


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

           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  pos‐
       sibly containing a decimal point, and an optional exponent field consist‐
       ing of an 'E' or 'e' followed by an optional '+' or  '-'  followed  by  a
       string of digits.

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

       The X keyboard model is broken into two  layers:   server-specific  codes
       (called  keycodes) which represent the physical keys, and server-indepen‐
       dent 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 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 cur‐
               rently pressed.  Most servers set up this list to initially  con‐
               tain  the various shift, control, and shift lock keys on the key‐

       keymap table
               Applications translate event keycodes  and  modifier  masks  into
               keysyms using a keysym table which contains one row for each key‐
               code and one column for various modifier states.  This  table  is
               initialized by the server to correspond to normal typewriter con‐
               ventions.  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 alpha‐
       betic 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 sec‐
       ond 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  low‐
       ercase  alphabetic,  then  the  corresponding  uppercase  keysym  is used

       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 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  appli‐
               cation'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

       -rv, -reverse
               Either  option indicates that the program should simulate reverse
               video if possible, often by swapping  the  foreground  and  back‐
               ground  colors.  Not all programs honor this or implement it cor‐
               rectly.  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 provide some
               sort of header identifying the window.

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

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

       To make the tailoring of applications to personal preferences  easier,  X
       provides  a  mechanism  for  storing default values for program resources
       (e.g. background color, window title, etc.) that is used by programs that
       use  toolkits based on the X Toolkit Intrinsics library libXt.  (Programs
       using the common Gtk+ and Qt  toolkits  use  other  configuration  mecha‐
       nisms.)  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  rea‐

       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 Resource‐
       Spec 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 recog‐
       nized and replaced by a newline character.  To allow a Value to be broken
       across  multiple lines in a text file, the two-character sequence ``\new‐
       line'' (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 back‐

       When an application looks for the value of a  resource,  it  specifies  a
       complete path in the hierarchy, with both class and instance names.  How‐
       ever, 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 compo‐
       nents,  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 speci‐
       fied.   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 fol‐
       lowing  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  appropri‐

       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 set‐
               ting 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  col‐
       lections 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 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 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),

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

              The first non-empty value among these three determines the current
              locale's  facet  for  character  handling,  and  in particular the
              default text encoding. See locale(7), setlocale(3), locale(1).

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

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

              This  must  point to a file containing X resources. The default is
              $HOME/.Xdefaults-<hostname>. Unlike $HOME/.Xresources, it is  con‐
              sulted 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


              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 set.
              This  must  point  to a file containing nonstandard keysym defini‐
              tions.  The default value is /usr/share/X11/XKeysymDB.

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

              This serves as main identifier for resources belonging to the pro‐
              gram 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 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 com‐
       mand, 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 stan‐
       dard 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

       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 (fre‐
       quently called .Xresources or .Xres in the user's home directory):

           *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), xdpy‐
       info(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  Intrin‐
       sics - 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  real‐
       ity 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  Con‐
       sortium, 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.

X Version 11                      xorg-docs 1.6                             X(7)