option - Add/retrieve window options to/from the option database
option add pattern value ?priority?
option get window name class
option readfile fileName ?priority?
command allows you to add entries to the Tk option database or
to retrieve options from the database. The add
form of the command adds
a new option to the database. Pattern
contains the option being
specified, and consists of names and/or classes separated by asterisks or
dots, in the usual X format (see PATTERN FORMAT
contains a text string to associate with pattern
; this is the value
that will be returned in calls to Tk_GetOption
or by invocations of the
command. If priority
is specified, it indicates the
priority level for this option (see below for legal values); it defaults to
. This command always returns an empty string.
The option clear
command clears the option database. Default options
(from the RESOURCE_MANAGER
property or the .Xdefaults
be reloaded automatically the next time an option is added to the database or
removed from it. This command always returns an empty string.
The option get
command returns the value of the option specified for
. If several entries in the
option database match window
, and class
, then the
command returns whichever was created with highest priority
there are several matching entries at the same priority level, then it returns
whichever entry was most recently entered into the option database. If there
are no matching entries, then the empty string is returned.
form of the command reads fileName
, which should have
the standard format for an X resource database such as .Xdefaults
adds all the options specified in that file to the option database. If
is specified, it indicates the priority level at which to
enter the options; priority
defaults to interactive
arguments to the option
command are normally
specified symbolically using one of the following values:
- Level 20. Used for default values hard-coded into widgets.
- Level 40. Used for options specified in application-specific startup
- Level 60. Used for options specified in user-specific defaults files, such
as .Xdefaults, resource databases loaded into the X server, or
user-specific startup files.
- Level 80. Used for options specified interactively after the application
starts running. If priority is not specified, it defaults to this
Any of the above keywords may be abbreviated. In addition, priorities may be
specified numerically using integers between 0 and 100, inclusive. The numeric
form is probably a bad idea except for new priority levels other than the ones
Patterns consist of a sequence of words separated by either periods,
“.”, or asterisks “*”. The overall pattern may
also be optionally preceded by an asterisk.
Each word in the pattern conventionally starts with either an upper-case letter
(in which case it denotes the class of either a widget or an option) or any
other character, when it denotes the name of a widget or option. The last word
in the pattern always indicates the option; the preceding ones constrain which
widgets that option will be looked for in.
When two words are separated by a period, the latter widget must be a direct
child of the former (or the option must apply to only the indicated widgets).
When two words are separated by an asterisk, any depth of widgets may lie
between the former and latter widgets (and the option applies to all widgets
that are children of the former widget).
If the overall pattern is preceded by an asterisk, then the overall pattern
applies anywhere it can throughout the whole widget hierarchy. Otherwise the
first word of the pattern is matched against the name and class of the
, which are usually set by options to
Instruct every button in the application to have red text on it unless
explicitly overridden (note that on some platforms the option is ignored):
option add *Button.foreground red startupFile
Allow users to control what happens in an entry widget when the Return key is
pressed by specifying a script in the option database and add a default option
for that which rings the bell:
bind .e <Return> [ option get .e returnCommand Command]
option add *.e.returnCommand bell widgetDefault
database, option, priority, retrieve