1XPROP(1) General Commands Manual XPROP(1)
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6 xprop - property displayer for X
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9 xprop [-help] [-grammar] [-id id] [-root] [-name name] [-frame] [-font
10 font] [-display display] [-len n] [-notype] [-fs file] [-remove prop‐
11 erty-name] [-set property-name value] [-spy] [-version] [-f atom format
12 [dformat]]* [format [dformat] atom]*
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15 The xprop utility is for displaying window and font properties in an X
16 server. One window or font is selected using the command line argu‐
17 ments or possibly in the case of a window, by clicking on the desired
18 window. A list of properties is then given, possibly with formatting
19 information.
20
22 -help Print out a summary of command line options.
23 -grammar
25 Print out a detailed grammar for all command line options.
26 -id id This argument allows the user to select window id on the com‐
28 mand line rather than using the pointer to select the target
29 window. This is very useful in debugging X applications where
30 the target window is not mapped to the screen or where the use
31 of the pointer might be impossible or interfere with the appli‐
32 cation.
33 -name name
35 This argument allows the user to specify that the window named
36 name is the target window on the command line rather than using
37 the pointer to select the target window.
38 -font font
40 This argument allows the user to specify that the properties of
41 font font should be displayed.
42 -root This argument specifies that X's root window is the target win‐
44 dow. This is useful in situations where the root window is
45 completely obscured.
46 -display display
48 This argument allows you to specify the server to connect to;
49 see X(7).
50 -len n Specifies that at most n bytes of any property should be read
52 or displayed.
53 -notype Specifies that the type of each property should not be dis‐
55 played.
56 -fs file
58 Specifies that file file should be used as a source of more
59 formats for properties.
60 -frame Specifies that when selecting a window by hand (i.e. if none of
62 -name, -root, or -id are given), look at the window manager
63 frame (if any) instead of looking for the client window.
64 -remove property-name
66 Specifies the name of a property to be removed from the indi‐
67 cated window.
68 -set property-name value
70 Specifies the name of a property and a property value, to be
71 set on the indicated window.
72 -spy Examine window properties forever, looking for property change
74 events.
75 -version
77 Print program version information and exit.
78 -f name format [dformat]
80 Specifies that the format for name should be format and that
81 the dformat for name should be dformat. If dformat is missing,
82 " = $0+\n" is assumed.
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85 For each of these properties, its value on the selected window or font
86 is printed using the supplied formatting information if any. If no
87 formatting information is supplied, internal defaults are used. If a
88 property is not defined on the selected window or font, "not defined"
89 is printed as the value for that property. If no property list is
90 given, all the properties possessed by the selected window or font are
91 printed.
92 A window may be selected in one of four ways. First, if the desired
94 window is the root window, the -root argument may be used. If the de‐
95 sired window is not the root window, it may be selected in two ways on
96 the command line, either by id number such as might be obtained from
97 xwininfo, or by name if the window possesses a name. The -id argument
98 selects a window by id number in either decimal or hex (must start with
99 0x) while the -name argument selects a window by name.
100 The last way to select a window does not involve the command line at
102 all. If none of -font, -id, -name, and -root are specified, a
103 crosshairs cursor is displayed and the user is allowed to choose any
104 visible window by pressing any pointer button in the desired window.
105 If it is desired to display properties of a font as opposed to a win‐
106 dow, the -font argument must be used.
107 Other than the above four arguments and the -help argument for obtain‐
109 ing help, and the -grammar argument for listing the full grammar for
110 the command line, all the other command line arguments are used in
111 specifying both the format of the properties to be displayed and how to
112 display them. The -len n argument specifies that at most n bytes of
113 any given property will be read and displayed. This is useful for ex‐
114 ample when displaying the cut buffer on the root window which could run
115 to several pages if displayed in full.
116 Normally each property name is displayed by printing first the property
118 name then its type (if it has one) in parentheses followed by its
119 value. The -notype argument specifies that property types should not
120 be displayed. The -fs argument is used to specify a file containing a
121 list of formats for properties while the -f argument is used to specify
122 the format for one property.
123 The formatting information for a property actually consists of two
125 parts, a format and a dformat. The format specifies the actual format‐
126 ting of the property (i.e., is it made up of words, bytes, or longs?,
127 etc.) while the dformat specifies how the property should be displayed.
128 The following paragraphs describe how to construct formats and dfor‐
130 mats. However, for the vast majority of users and uses, this should
131 not be necessary as the built in defaults contain the formats and dfor‐
132 mats necessary to display all the standard properties. It should only
133 be necessary to specify formats and dformats if a new property is being
134 dealt with or the user dislikes the standard display format. New users
135 especially are encouraged to skip this part.
136 A format consists of one of 0, 8, 16, or 32 followed by a sequence of
138 one or more format characters. The 0, 8, 16, or 32 specifies how many
139 bits per field there are in the property. Zero is a special case mean‐
140 ing use the field size information associated with the property itself.
141 (This is only needed for special cases like type INTEGER which is actu‐
142 ally three different types depending on the size of the fields of the
143 property.)
144 A value of 8 means that the property is a sequence of bytes while a
146 value of 16 would mean that the property is a sequence of words. The
147 difference between these two lies in the fact that the sequence of
148 words will be byte swapped while the sequence of bytes will not be when
149 read by a machine of the opposite byte order of the machine that origi‐
150 nally wrote the property. For more information on how properties are
151 formatted and stored, consult the Xlib manual.
152 Once the size of the fields has been specified, it is necessary to
154 specify the type of each field (i.e., is it an integer, a string, an
155 atom, or what?) This is done using one format character per field. If
156 there are more fields in the property than format characters supplied,
157 the last character will be repeated as many times as necessary for the
158 extra fields. The format characters and their meaning are as follows:
159 a The field holds an atom number. A field of this type should be
161 of size 32.
162 b The field is an boolean. A 0 means false while anything else
164 means true.
165 c The field is an unsigned number, a cardinal.
167 i The field is a signed integer.
169 m The field is a set of bit flags, 1 meaning on.
171 o The field is an array of icons, packed as a sequence of 32 bit
173 numbers consisting of the width, height and ARGB pixel values,
174 as defined for the _NET_WM_ICON property in the Extended Window
175 Manager Hints specification. A field of this type must be of
176 size 32.
177 s This field and the next ones until either a 0 or the end of the
179 property represent a sequence of bytes. This format character
180 is only usable with a field size of 8 and is most often used to
181 represent a string.
182 t This field and the next ones until either a 0 or the end of the
184 property represent an internationalized text string. This format
185 character is only usable with a field size of 8. The string is
186 assumed to be in an ICCCM compliant encoding and is converted to
187 the current locale encoding before being output.
188 u This field and the next ones until either a 0 or the end of the
190 property represent an UTF-8 encoded unicode string. This format
191 character is only usable with a field size of 8. If the string
192 is found to be an invalid character, the type of encoding viola‐
193 tion is printed instead, followed by the string formatted using
194 's'. When in an environment not capable of displaying UTF-8 en‐
195 coded string, behaviour is identical to 's'.
196 x The field is a hex number (like 'c' but displayed in hex - most
198 useful for displaying window ids and the like)
199 An example format is 32ica which is the format for a property of three
201 fields of 32 bits each, the first holding a signed integer, the second
202 an unsigned integer, and the third an atom.
203 The format of a dformat unlike that of a format is not so rigid. The
205 only limitations on a dformat is that one may not start with a letter
206 or a dash. This is so that it can be distinguished from a property
207 name or an argument. A dformat is a text string containing special
208 characters instructing that various fields be printed at various points
209 in a manner similar to the formatting string used by printf. For exam‐
210 ple, the dformat " is ( $0, $1 \)\n" would render the POINT 3, -4 which
211 has a format of 32ii as " is ( 3, -4 )\n".
212 Any character other than a $, ?, \, or a ( in a dformat prints as it‐
214 self. To print out one of $, ?, \, or ( precede it by a \. For exam‐
215 ple, to print out a $, use \$. Several special backslash sequences are
216 provided as shortcuts. \n will cause a newline to be displayed while
217 \t will cause a tab to be displayed. \o where o is an octal number
218 will display character number o.
219 A $ followed by a number n causes field number n to be displayed. The
221 format of the displayed field depends on the formatting character used
222 to describe it in the corresponding format. I.e., if a cardinal is de‐
223 scribed by 'c' it will print in decimal while if it is described by a
224 'x' it is displayed in hex.
225 If the field is not present in the property (this is possible with some
227 properties), <field not available> is displayed instead. $n+ will dis‐
228 play field number n then a comma then field number n+1 then another
229 comma then ... until the last field defined. If field n is not de‐
230 fined, nothing is displayed. This is useful for a property that is a
231 list of values.
232 A ? is used to start a conditional expression, a kind of if-then state‐
234 ment. ?exp(text) will display text if and only if exp evaluates to
235 non-zero. This is useful for two things. First, it allows fields to
236 be displayed if and only if a flag is set. And second, it allows a
237 value such as a state number to be displayed as a name rather than as
238 just a number. The syntax of exp is as follows:
239 exp ::= term | term=exp | !exp
241 term ::= n | $n | mn
243 The ! operator is a logical ``not'', changing 0 to 1 and any non-zero
245 value to 0. = is an equality operator. Note that internally all ex‐
246 pressions are evaluated as 32 bit numbers so -1 is not equal to 65535.
247 = returns 1 if the two values are equal and 0 if not. n represents the
248 constant value n while $n represents the value of field number n. mn
249 is 1 if flag number n in the first field having format character 'm' in
250 the corresponding format is 1, 0 otherwise.
251 Examples: ?m3(count: $3\n) displays field 3 with a label of count if
253 and only if flag number 3 (count starts at 0!) is on.
254 ?$2=0(True)?!$2=0(False) displays the inverted value of field 2 as a
255 boolean.
256 In order to display a property, xprop needs both a format and a dfor‐
258 mat. Before xprop uses its default values of a format of 32x and a
259 dformat of " = { $0+ }\n", it searches several places in an attempt to
260 find more specific formats. First, a search is made using the name of
261 the property. If this fails, a search is made using the type of the
262 property. This allows type STRING to be defined with one set of for‐
263 mats while allowing property WM_NAME which is of type STRING to be de‐
264 fined with a different format. In this way, the display formats for a
265 given type can be overridden for specific properties.
266 The locations searched are in order: the format if any specified with
268 the property name (as in 8x WM_NAME), the formats defined by -f options
269 in last to first order, the contents of the file specified by the -fs
270 option if any, the contents of the file specified by the environmental
271 variable XPROPFORMATS if any, and finally xprop's built in file of for‐
272 mats.
273 The format of the files referred to by the -fs argument and the XPROP‐
275 FORMATS variable is one or more lines of the following form:
276 name format [dformat]
278 Where name is either the name of a property or the name of a type, for‐
280 mat is the format to be used with name and dformat is the dformat to be
281 used with name. If dformat is not present, " = $0+\n" is assumed.
282
284 To display the name of the root window: xprop -root WM_NAME
285 To display the window manager hints for the clock: xprop -name xclock
287 WM_HINTS
288 To display the start of the cut buffer: xprop -root -len 100 CUT_BUF‐
290 FER0
291 To display the point size of the fixed font: xprop -font fixed
293 POINT_SIZE
294 To display all the properties of window # 0x200007: xprop -id 0x200007
296 To set a simple string property: xprop -root -format MY_ATOM_NAME 8s
298 -set MY_ATOM_NAME "my_value"
299
301 DISPLAY To get default display.
302 XPROPFORMATS
304 Specifies the name of a file from which additional formats are
305 to be obtained.
306
308 X(7), xdpyinfo(1), xwininfo(1), xdriinfo(1), glxinfo(1), xvinfo(1)
309
311 Mark Lillibridge, MIT Project Athena
312X Version 11 xprop 1.2.5 XPROP(1)