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 -verson Print program version information and exit.
77 -f name format [dformat]
79 Specifies that the format for name should be format and that
80 the dformat for name should be dformat. If dformat is missing,
81 " = $0+\n" is assumed.
82
84 For each of these properties, its value on the selected window or font
85 is printed using the supplied formatting information if any. If no
86 formatting information is supplied, internal defaults are used. If a
87 property is not defined on the selected window or font, "not defined"
88 is printed as the value for that property. If no property list is
89 given, all the properties possessed by the selected window or font are
90 printed.
91 A window may be selected in one of four ways. First, if the desired
93 window is the root window, the -root argument may be used. If the
94 desired window is not the root window, it may be selected in two ways
95 on the command line, either by id number such as might be obtained from
96 xwininfo, or by name if the window possesses a name. The -id argument
97 selects a window by id number in either decimal or hex (must start with
98 0x) while the -name argument selects a window by name.
99 The last way to select a window does not involve the command line at
101 all. If none of -font, -id, -name, and -root are specified, a
102 crosshairs cursor is displayed and the user is allowed to choose any
103 visible window by pressing any pointer button in the desired window.
104 If it is desired to display properties of a font as opposed to a win‐
105 dow, the -font argument must be used.
106 Other than the above four arguments and the -help argument for obtain‐
108 ing help, and the -grammar argument for listing the full grammar for
109 the command line, all the other command line arguments are used in
110 specifying both the format of the properties to be displayed and how to
111 display them. The -len n argument specifies that at most n bytes of
112 any given property will be read and displayed. This is useful for
113 example when displaying the cut buffer on the root window which could
114 run to several pages if displayed in full.
115 Normally each property name is displayed by printing first the property
117 name then its type (if it has one) in parentheses followed by its
118 value. The -notype argument specifies that property types should not
119 be displayed. The -fs argument is used to specify a file containing a
120 list of formats for properties while the -f argument is used to specify
121 the format for one property.
122 The formatting information for a property actually consists of two
124 parts, a format and a dformat. The format specifies the actual format‐
125 ting of the property (i.e., is it made up of words, bytes, or longs?,
126 etc.) while the dformat specifies how the property should be displayed.
127 The following paragraphs describe how to construct formats and dfor‐
129 mats. However, for the vast majority of users and uses, this should
130 not be necessary as the built in defaults contain the formats and dfor‐
131 mats necessary to display all the standard properties. It should only
132 be necessary to specify formats and dformats if a new property is being
133 dealt with or the user dislikes the standard display format. New users
134 especially are encouraged to skip this part.
135 A format consists of one of 0, 8, 16, or 32 followed by a sequence of
137 one or more format characters. The 0, 8, 16, or 32 specifies how many
138 bits per field there are in the property. Zero is a special case mean‐
139 ing use the field size information associated with the property itself.
140 (This is only needed for special cases like type INTEGER which is actu‐
141 ally three different types depending on the size of the fields of the
142 property.)
143 A value of 8 means that the property is a sequence of bytes while a
145 value of 16 would mean that the property is a sequence of words. The
146 difference between these two lies in the fact that the sequence of
147 words will be byte swapped while the sequence of bytes will not be when
148 read by a machine of the opposite byte order of the machine that origi‐
149 nally wrote the property. For more information on how properties are
150 formatted and stored, consult the Xlib manual.
151 Once the size of the fields has been specified, it is necessary to
153 specify the type of each field (i.e., is it an integer, a string, an
154 atom, or what?) This is done using one format character per field. If
155 there are more fields in the property than format characters supplied,
156 the last character will be repeated as many times as necessary for the
157 extra fields. The format characters and their meaning are as follows:
158 a The field holds an atom number. A field of this type should be
160 of size 32.
161 b The field is an boolean. A 0 means false while anything else
163 means true.
164 c The field is an unsigned number, a cardinal.
166 i The field is a signed integer.
168 m The field is a set of bit flags, 1 meaning on.
170 o The field is an array of icons, packed as a sequence of 32 bit
172 numbers consisting of the width, height and ARGB pixel values,
173 as defined for the _NET_WM_ICON property in the Extended Window
174 Manager Hints specification. A field of this type must be of
175 size 32.
176 s This field and the next ones until either a 0 or the end of the
178 property represent a sequence of bytes. This format character
179 is only usable with a field size of 8 and is most often used to
180 represent a string.
181 t This field and the next ones until either a 0 or the end of the
183 property represent an internationalized text string. This format
184 character is only usable with a field size of 8. The string is
185 assumed to be in an ICCCM compliant encoding and is converted to
186 the current locale encoding before being output.
187 u This field and the next ones until either a 0 or the end of the
189 property represent an UTF-8 encoded unicode string. This format
190 character is only usable with a field size of 8. If the string
191 is found to be an invalid character, the type of encoding viola‐
192 tion is printed instead, followed by the string formatted using
193 's'. When in an environment not capable of displaying UTF-8
194 encoded string, behaviour is identical to 's'.
195 x The field is a hex number (like 'c' but displayed in hex - most
197 useful for displaying window ids and the like)
198 An example format is 32ica which is the format for a property of three
200 fields of 32 bits each, the first holding a signed integer, the second
201 an unsigned integer, and the third an atom.
202 The format of a dformat unlike that of a format is not so rigid. The
204 only limitations on a dformat is that one may not start with a letter
205 or a dash. This is so that it can be distinguished from a property
206 name or an argument. A dformat is a text string containing special
207 characters instructing that various fields be printed at various points
208 in a manner similar to the formatting string used by printf. For exam‐
209 ple, the dformat " is ( $0, $1 \)\n" would render the POINT 3, -4 which
210 has a format of 32ii as " is ( 3, -4 )\n".
211 Any character other than a $, ?, \, or a ( in a dformat prints as
213 itself. To print out one of $, ?, \, or ( precede it by a \. For
214 example, to print out a $, use \$. Several special backslash sequences
215 are provided as shortcuts. \n will cause a newline to be displayed
216 while \t will cause a tab to be displayed. \o where o is an octal num‐
217 ber will display character number o.
218 A $ followed by a number n causes field number n to be displayed. The
220 format of the displayed field depends on the formatting character used
221 to describe it in the corresponding format. I.e., if a cardinal is
222 described by 'c' it will print in decimal while if it is described by a
223 'x' it is displayed in hex.
224 If the field is not present in the property (this is possible with some
226 properties), <field not available> is displayed instead. $n+ will dis‐
227 play field number n then a comma then field number n+1 then another
228 comma then ... until the last field defined. If field n is not
229 defined, nothing is displayed. This is useful for a property that is a
230 list of values.
231 A ? is used to start a conditional expression, a kind of if-then state‐
233 ment. ?exp(text) will display text if and only if exp evaluates to
234 non-zero. This is useful for two things. First, it allows fields to
235 be displayed if and only if a flag is set. And second, it allows a
236 value such as a state number to be displayed as a name rather than as
237 just a number. The syntax of exp is as follows:
238 exp ::= term | term=exp | !exp
240 term ::= n | $n | mn
242 The ! operator is a logical ``not'', changing 0 to 1 and any non-zero
244 value to 0. = is an equality operator. Note that internally all
245 expressions are evaluated as 32 bit numbers so -1 is not equal to
246 65535. = returns 1 if the two values are equal and 0 if not. n repre‐
247 sents the constant value n while $n represents the value of field num‐
248 ber n. mn is 1 if flag number n in the first field having format char‐
249 acter 'm' in the corresponding format is 1, 0 otherwise.
250 Examples: ?m3(count: $3\n) displays field 3 with a label of count if
252 and only if flag number 3 (count starts at 0!) is on.
253 ?$2=0(True)?!$2=0(False) displays the inverted value of field 2 as a
254 boolean.
255 In order to display a property, xprop needs both a format and a dfor‐
257 mat. Before xprop uses its default values of a format of 32x and a
258 dformat of " = { $0+ }\n", it searches several places in an attempt to
259 find more specific formats. First, a search is made using the name of
260 the property. If this fails, a search is made using the type of the
261 property. This allows type STRING to be defined with one set of for‐
262 mats while allowing property WM_NAME which is of type STRING to be
263 defined with a different format. In this way, the display formats for
264 a given type can be overridden for specific properties.
265 The locations searched are in order: the format if any specified with
267 the property name (as in 8x WM_NAME), the formats defined by -f options
268 in last to first order, the contents of the file specified by the -fs
269 option if any, the contents of the file specified by the environmental
270 variable XPROPFORMATS if any, and finally xprop's built in file of for‐
271 mats.
272 The format of the files referred to by the -fs argument and the XPROP‐
274 FORMATS variable is one or more lines of the following form:
275 name format [dformat]
277 Where name is either the name of a property or the name of a type, for‐
279 mat is the format to be used with name and dformat is the dformat to be
280 used with name. If dformat is not present, " = $0+\n" is assumed.
281
283 To display the name of the root window: xprop -root WM_NAME
284 To display the window manager hints for the clock: xprop -name xclock
286 WM_HINTS
287 To display the start of the cut buffer: xprop -root -len 100 CUT_BUF‐
289 FER0
290 To display the point size of the fixed font: xprop -font fixed
292 POINT_SIZE
293 To display all the properties of window # 0x200007: xprop -id 0x200007
295 To set a simple string property: xprop -root -format MY_ATOM_NAME 8s
297 -set MY_ATOM_NAME "my_value"
298
300 DISPLAY To get default display.
301 XPROPFORMATS
303 Specifies the name of a file from which additional formats are
304 to be obtained.
305
307 X(7), xdpyinfo(1), xwininfo(1), xdriinfo(1), glxinfo(1), xvinfo(1)
308
310 Mark Lillibridge, MIT Project Athena
311X Version 11 xprop 1.2.3 XPROP(1)