# xprop(1) - man - phpMan [XPROP(1)](https://www.chedong.com/phpMan.php/man/XPROP/1/markdown) General Commands Manual [XPROP(1)](https://www.chedong.com/phpMan.php/man/XPROP/1/markdown) ## NAME xprop - property displayer for X ## SYNOPSIS **xprop** [-help] [-grammar] [-id _id_] [-root] [-name _name_] [-frame] [-font _font_] [-display _dis__‐ _play_] [-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 ### -grammar Print out a detailed grammar for all command line options. ### -id ing the pointer to select the target window. This is very useful in debugging X ap‐ plications where the target window is not mapped to the screen or where the use of the pointer might be impossible or interfere with the application. ### -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 This argument allows the user to specify that the properties of font _font_ should be displayed. ### -root situations where the root window is completely obscured. ### -display This argument allows you to specify the server to connect to; see [_X(7)](https://www.chedong.com/phpMan.php/man/X/7/markdown)_. ### -len ### -notype ### -fs Specifies that file _file_ should be used as a source of more formats for properties. ### -frame -name -root -id are given), look at the window manager frame (if any) instead of looking for the client window. ### -remove Specifies the name of a property to be removed from the indicated window. ### -set Specifies the name of a property and a property value, to be set on the indicated window. ### -spy ### -version Print program version information and exit. ### -f 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. ## 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 information is supplied, internal defaults are used. If a property is not defined on the selected window or font, "not de‐ fined" 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 printed. A window may be selected in one of four ways. First, if the desired window is the root win‐ dow, 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 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 win‐ dow 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 window, the -font argument must be used. Other than the above four arguments and the -help argument for obtaining help, and the -gram‐ mar 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 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 argument is used to specify a file contain‐ ing 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 formatting of the property (i.e., is it made up of words, bytes, or longs?, etc.) while the _dformat_ specifies how the property should be dis‐ played. The following paragraphs describe how to construct _format_s and _dformat_s. However, for the vast majority of users and uses, this should not be necessary as the built in defaults con‐ tain the _format_s and _dformat_s necessary to display all the standard properties. It should only be necessary to specify _format_s and _dformat_s 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 special 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 prop‐ erty. For more information on how properties are formatted and stored, consult the Xlib man‐ ual. 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 sup‐ plied, 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 envi‐ ronment 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 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 distin‐ guished 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 dis‐ played 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 de‐ scribed by a 'x' it is displayed in hex. If the field is not present in the property (this is possible with some properties), is displayed instead. $_n_+ will display 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 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 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_ | m_n_ 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 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_ repre‐ sents the constant value _n_ while $_n_ represents the value of field number _n_. m_n_ 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 al‐ lows 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 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 environ‐ mental variable XPROPFORMATS if any, and finally _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 obtained. ## SEE ALSO [X(7)](https://www.chedong.com/phpMan.php/man/X/7/markdown), [xdpyinfo(1)](https://www.chedong.com/phpMan.php/man/xdpyinfo/1/markdown), [xwininfo(1)](https://www.chedong.com/phpMan.php/man/xwininfo/1/markdown), [xdriinfo(1)](https://www.chedong.com/phpMan.php/man/xdriinfo/1/markdown), [glxinfo(1)](https://www.chedong.com/phpMan.php/man/glxinfo/1/markdown), [xvinfo(1)](https://www.chedong.com/phpMan.php/man/xvinfo/1/markdown) ## AUTHOR Mark Lillibridge, MIT Project Athena X Version 11 xprop 1.2.4 [XPROP(1)](https://www.chedong.com/phpMan.php/man/XPROP/1/markdown)