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XPROP(1)		    General Commands Manual		      XPROP(1)

       xprop - property	displayer for X

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

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

       -help   Print out a summary of command line options.

	       Print out a detailed grammar for	all command line options.

       -id id  This argument allows the	user to	select window id on  the  com-
	       mand  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 interfere with the	appli-

       -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 win-
	       dow.   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 displayed.

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

       -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) instead of looking for the client	window.

       -remove property-name
	       Specifies the name of a property	to be removed from  the	 indi-
	       cated window.

       -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

	       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 assumed.

       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  information	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 selected window or font  are

       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  de-
       sired  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 possesses 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  displayed 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 win-
       dow, the	-font argument must be used.

       Other than the above four arguments and the -help argument for  obtain-
       ing  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 specifies that at most  n  bytes  of
       any  given property will	be read	and displayed.	This is	useful for ex-
       ample 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 argument 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	format and a dformat.  The format specifies the	actual format-
       ting of the property (i.e., is it made up of words, bytes,  or  longs?,
       etc.) while the dformat specifies how the property should be displayed.

       The  following  paragraphs  describe how	to construct formats and dfor-
       mats.  However, for the vast majority of	users and  uses,  this	should
       not be necessary	as the built in	defaults contain the formats and dfor-
       mats 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 mean-
       ing use the field size information associated with the property itself.
       (This is	only needed for	special	cases like type	INTEGER	which is actu-
       ally three different types depending on the size	of the fields  of  the

       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	origi-
       nally 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	viola-
	      tion  is printed instead,	followed by the	string formatted using
	      's'. When	in an environment not capable of displaying UTF-8  en-
	      coded 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 integer, and	the third an atom.

       The format of a dformat unlike that of a	format is not so  rigid.   The
       only  limitations  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 exam-
       ple, 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 it-
       self.  To print out one of $, ?,	\, or (	precede	it by a	\.  For	 exam-
       ple, 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 de-
       scribed	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
       properties), <field not available> is displayed instead.	 $n+ will dis-
       play field number n then	a comma	then field  number  n+1	 then  another
       comma  then  ...	 until	the last field defined.	 If field n is not de-
       fined, 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	state-
       ment.  ?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 displayed 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 ex-
       pressions are evaluated as 32 bit numbers so -1 is not equal to	65535.
       = returns 1 if the two values are equal and 0 if	not.  n	represents the
       constant	value n	while $n represents 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

       In  order  to display a property, xprop needs both a format and a dfor-
       mat.  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  for-
       mats  while allowing property WM_NAME which is of type STRING to	be de-
       fined 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 property 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 finally xprop's built in file of for-

       The format of the files referred	to by the -fs argument and the	XPROP-
       FORMATS 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, for-
       mat 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.

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

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

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

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

       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"

       DISPLAY To get default display.

	       Specifies  the name of a	file from which	additional formats are
	       to be obtained.

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

       Mark Lillibridge, MIT Project Athena

X Version 11			  xprop	1.2.4			      XPROP(1)


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