XPROP(1)                        General Commands Manual                        XPROP(1)

NAME
       xprop - property displayer for X

SYNOPSIS
       xprop  [-help]  [-grammar]  [-id  id] [-root] [-name name] [-frame] [-font font]
       [-display display] [-len n] [-notype] [-fs file] [-remove  property-name]  [-set
       property-name  value]  [-spy]  [-version]  [-f  atom  format [dformat]]* [format
       [dformat] atom]*

SUMMARY
       The xprop utility is for displaying window and font properties in an  X  server.
       One  window  or font is selected using the command line arguments or possibly in
       the case of a window, by clicking on the desired window.  A list  of  properties
       is then given, possibly with formatting information.

OPTIONS
       -help   Print out a summary of command line options.

       -grammar
               Print out a detailed grammar for all command line options.

       -id id  This  argument  allows  the user to select window id on the command line
               rather than using the pointer to select the target window.  This is very
               useful in debugging X applications where the target window is not mapped
               to the screen or where the use of the pointer might be impossible or in‐
               terfere with the application.

       -name name
               This  argument  allows the user to specify that the window named name is
               the target window on the command line rather than using the  pointer  to
               select the target window.

       -font font
               This  argument  allows  the  user to specify that the properties of font
               font should be displayed.

       -root   This argument specifies that X's root window is the target window.  This
               is useful in situations where the root window is completely obscured.

       -display display
               This argument allows you to specify the server to connect to; see X(7).

       -len n  Specifies  that  at  most n bytes of any property should be read or dis‐
               played.

       -notype Specifies that the type of each property should not be displayed.

       -fs file
               Specifies that file file should be used as a source of more formats  for
               properties.

       -frame  Specifies  that  when selecting a window by hand (i.e. if none of -name,
               -root, or -id are given), look at the window manager frame (if any)  in‐
               stead of looking for the client window.

       -remove property-name
               Specifies  the  name of a property to be removed from the indicated win‐
               dow.

       -set property-name value
               Specifies the name of a property and a property value, to be set on  the
               indicated window.

       -spy    Examine window properties forever, looking for property change events.

       -verson Print program version information and exit.

       -f name format [dformat]
               Specifies that the format for name should be format and that the dformat
               for name should be dformat.  If dformat is missing, " =  $0+\n"  is  as‐
               sumed.

DESCRIPTION
       For  each  of  these  properties,  its  value  on the selected window or font is
       printed using the supplied formatting information if any.  If no formatting  in‐
       formation is supplied, internal defaults are used.  If a property is not defined
       on the selected window or font, "not defined" is printed as the value  for  that
       property.  If no property list is given, all the properties possessed by the se‐
       lected window or font are printed.

       A window may be selected in one of four ways.  First, if the desired  window  is
       the  root  window, the -root argument may be used.  If the desired window is not
       the root window, it may be selected in two ways on the command line,  either  by
       id number such as might be obtained from xwininfo, or by name if the window pos‐
       sesses a name.  The -id argument selects a window by id number in either decimal
       or hex (must start with 0x) while the -name argument selects a window by name.

       The  last  way  to select a window does not involve the command line at all.  If
       none of -font, -id, -name, and -root are specified, a crosshairs cursor is  dis‐
       played  and  the  user  is  allowed to choose any visible window by pressing any
       pointer button in the desired window.  If it is desired to display properties of
       a font as opposed to a window, the -font argument must be used.

       Other  than  the above four arguments and the -help argument for obtaining help,
       and the -grammar argument for listing the full grammar for the command line, all
       the  other  command line arguments are used in specifying both the format of the
       properties to be displayed and how to display them.  The -len n argument  speci‐
       fies  that  at  most  n  bytes of any given property will be read and displayed.
       This is useful for example when displaying the cut buffer  on  the  root  window
       which could run to several pages if displayed in full.

       Normally  each  property  name  is displayed by printing first the property name
       then its type (if it has one) in parentheses followed by its value.  The -notype
       argument  specifies  that property types should not be displayed.  The -fs argu‐
       ment is used to specify a file containing a list of formats for properties while
       the -f argument is used to specify the format for one property.

       The formatting information for a property actually consists of two parts, a for‐
       mat and a dformat.  The format specifies the actual formatting of  the  property
       (i.e.,  is it made up of words, bytes, or longs?, etc.) while the dformat speci‐
       fies how the property should be displayed.

       The following paragraphs describe how to construct formats and  dformats.   How‐
       ever,  for  the vast majority of users and uses, this should not be necessary as
       the built in defaults contain the formats and dformats necessary to display  all
       the  standard  properties.   It  should only be necessary to specify formats and
       dformats if a new property is being dealt with or the user dislikes the standard
       display format.  New users especially are encouraged to skip this part.

       A  format  consists  of  one of 0, 8, 16, or 32 followed by a sequence of one or
       more format characters.  The 0, 8, 16, or 32 specifies how many bits  per  field
       there  are  in  the property.  Zero is a special case meaning use the field size
       information associated with the property itself.  (This is only needed for  spe‐
       cial  cases  like type INTEGER which is actually three different types depending
       on the size of the fields of the property.)

       A value of 8 means that the property is a sequence of bytes while a value of  16
       would  mean  that  the  property is a sequence of words.  The difference between
       these two lies in the fact that the sequence of words will be byte swapped while
       the  sequence  of  bytes will not be when read by a machine of the opposite byte
       order of the machine that originally wrote the property.  For  more  information
       on how properties are formatted and stored, consult the Xlib manual.

       Once  the  size of the fields has been specified, it is necessary to specify the
       type of each field (i.e., is it an integer, a string, an atom, or  what?)   This
       is  done  using one format character per field.  If there are more fields in the
       property than format characters supplied, the last character will be repeated as
       many  times  as necessary for the extra fields.  The format characters and their
       meaning are as follows:

       a      The field holds an atom number.  A field of this type should be  of  size
              32.

       b      The field is an boolean.  A 0 means false while anything else means true.

       c      The field is an unsigned number, a cardinal.

       i      The field is a signed integer.

       m      The field is a set of bit flags, 1 meaning on.

       o      The  field  is  an array of icons, packed as a sequence of 32 bit numbers
              consisting of the width, height and ARGB pixel values, as defined for the
              _NET_WM_ICON property in the Extended Window Manager Hints specification.
              A field of this type must be of size 32.

       s      This field and the next ones until either a 0 or the end of the  property
              represent a sequence of bytes.  This format character is only usable with
              a field size of 8 and is most often used to represent a string.

       t      This field and the next ones until either a 0 or the end of the  property
              represent an internationalized text string. This format character is only
              usable with a field size of 8. The string is assumed to be  in  an  ICCCM
              compliant encoding and is converted to the current locale encoding before
              being output.

       u      This field and the next ones until either a 0 or the end of the  property
              represent  an UTF-8 encoded unicode string. This format character is only
              usable with a field size of 8. If the string is found to  be  an  invalid
              character, the type of encoding violation is printed instead, followed by
              the string formatted using 's'. When in an  environment  not  capable  of
              displaying UTF-8 encoded string, behaviour is identical to 's'.

       x      The  field  is  a hex number (like 'c' but displayed in hex - most useful
              for displaying window ids and the like)

       An example format is 32ica which is the format for a property of three fields of
       32  bits  each, the first holding a signed integer, the second an unsigned inte‐
       ger, and the third an atom.

       The format of a dformat unlike that of a format is not so rigid.  The only limi‐
       tations on a dformat is that one may not start with a letter or a dash.  This is
       so that it can be distinguished from a property name or an argument.  A  dformat
       is  a  text string containing special characters instructing that various fields
       be printed at various points in a manner similar to the formatting  string  used
       by  printf.  For example, the dformat " is ( $0, $1 \)\n" would render the POINT
       3, -4 which has a format of 32ii as " is ( 3, -4 )\n".

       Any character other than a $, ?, \, or a ( in a dformat prints  as  itself.   To
       print  out  one of $, ?, \, or ( precede it by a \.  For example, to print out a
       $, use \$.  Several special backslash sequences are provided as  shortcuts.   \n
       will  cause a newline to be displayed while \t will cause a tab to be displayed.
       \o where o is an octal number will display character number o.

       A $ followed by a number n causes field number n to be displayed.  The format of
       the  displayed  field depends on the formatting character used to describe it in
       the corresponding format.  I.e., if a cardinal is described by 'c' it will print
       in decimal while if it is described by a 'x' it is displayed in hex.

       If  the field is not present in the property (this is possible with some proper‐
       ties), <field not available> is displayed instead.  $n+ will display field  num‐
       ber  n  then a comma then field number n+1 then another comma then ... until the
       last field defined.  If field n is not defined, nothing is displayed.   This  is
       useful for a property that is a list of values.

       A  ?  is  used  to  start a conditional expression, a kind of if-then statement.
       ?exp(text) will display text if and only if exp evaluates to non-zero.  This  is
       useful for two things.  First, it allows fields to be displayed if and only if a
       flag is set.  And second, it allows a value such as a state number  to  be  dis‐
       played as a name rather than as just a number.  The syntax of exp is as follows:

       exp    ::= term | term=exp | !exp

       term   ::= n | $n | mn

       The  !  operator is a logical ``not'', changing 0 to 1 and any non-zero value to
       0.  = is an equality operator.  Note that internally all expressions are  evalu‐
       ated as 32 bit numbers so -1 is not equal to 65535.  = returns 1 if the two val‐
       ues are equal and 0 if not.  n represents the constant value n while  $n  repre‐
       sents  the value of field number n.  mn is 1 if flag number n in the first field
       having format character 'm' in the corresponding format is 1, 0 otherwise.

       Examples: ?m3(count: $3\n) displays field 3 with a label of count if and only if
       flag number 3 (count starts at 0!) is on.  ?$2=0(True)?!$2=0(False) displays the
       inverted value of field 2 as a boolean.

       In order to display a property, xprop needs both a format and a dformat.  Before
       xprop  uses  its  default  values  of a format of 32x and a dformat of " = { $0+
       }\n", it searches several places in an attempt to find  more  specific  formats.
       First, a search is made using the name of the property.  If this fails, a search
       is made using the type of the property.  This allows type STRING to  be  defined
       with  one set of formats while allowing property WM_NAME which is of type STRING
       to be defined with a different format.  In this way, the display formats  for  a
       given type can be overridden for specific properties.

       The  locations searched are in order: the format if any specified with the prop‐
       erty name (as in 8x WM_NAME), the formats defined by -f options in last to first
       order, the contents of the file specified by the -fs option if any, the contents
       of the file specified by the environmental variable XPROPFORMATS if any, and fi‐
       nally xprop's built in file of formats.

       The  format  of  the  files referred to by the -fs argument and the XPROPFORMATS
       variable is one or more lines of the following form:

       name format [dformat]

       Where name is either the name of a property or the name of a type, format is the
       format to be used with name and dformat is the dformat to be used with name.  If
       dformat is not present, " = $0+\n" is assumed.

EXAMPLES
       To display the name of the root window: xprop -root WM_NAME

       To display the window manager hints for the clock: xprop -name xclock WM_HINTS

       To display the start of the cut buffer: xprop -root -len 100 CUT_BUFFER0

       To display the point size of the fixed font: xprop -font fixed POINT_SIZE

       To display all the properties of window # 0x200007: xprop -id 0x200007

       To set a simple string  property:  xprop  -root  -format  MY_ATOM_NAME  8s  -set
       MY_ATOM_NAME  "my_value"

ENVIRONMENT
       DISPLAY To get default display.

       XPROPFORMATS
               Specifies the name of a file from which additional formats are to be ob‐
               tained.

SEE ALSO
       X(7), xdpyinfo(1), xwininfo(1), xdriinfo(1), glxinfo(1), xvinfo(1)

AUTHOR
       Mark Lillibridge, MIT Project Athena

X Version 11                          xprop 1.2.3                              XPROP(1)

usage:  xprop [-options ...] [[format [dformat]] atom] ...

where options include:
    -grammar                       print out full grammar for command line
    -display host:dpy              the X server to contact
    -id id                         resource id of window to examine
    -name name                     name of window to examine
    -font name                     name of font to examine
    -remove propname               remove a property
    -set propname value            set a property to a given value
    -root                          examine the root window
    -len n                         display at most n bytes of any property
    -notype                        do not display the type field
    -fs filename                   where to look for formats for properties
    -frame                         don't ignore window manager frames
    -f propname format [dformat]   formats to use for property of given name
    -spy                           examine window properties forever
    -version                       print program version