option(n)                    Tk Built-In Commands                    option(n)



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NAME
       option - Add/retrieve window options to/from the option database

SYNOPSIS
       option add pattern value ?priority?
       option clear
       option get window name class
       option readfile fileName ?priority?
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DESCRIPTION
       The option 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).  Value 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 option get
       command.  If priority is specified, it indicates the priority level for
       this option (see below for legal values);  it defaults to interactive.
       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 file) will 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
       window under name and class.  If several entries in the option database
       match window, name, and class, then the command returns whichever was
       created with highest priority level.  If 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.

       The readfile form of the command reads fileName, which should have the
       standard format for an X resource database such as .Xdefaults, and adds
       all the options specified in that file to the option database.  If
       priority is specified, it indicates the priority level at which to
       enter the options;  priority defaults to interactive.

       The priority arguments to the option command are normally specified
       symbolically using one of the following values:

       widgetDefault
              Level 20.  Used for default values hard-coded into widgets.

       startupFile
              Level 40.  Used for options specified in application-specific
              startup files.

       userDefault
              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.

       interactive
              Level 80.  Used for options specified interactively after the
              application starts running.  If priority is not specified, it
              defaults to this level.

       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 given above.

PATTERN FORMAT
       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 "."  toplevel, which are usually set by options to wish.

EXAMPLES
       Instruct every button in the application to have red text on it unless
       explicitly overridden, by setting the foreground for the Button class
       (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:
              entry .e
              bind .e <Return> [option get .e returnCommand Command]
              option add *.e.returnCommand bell widgetDefault

SEE ALSO
       options(n), wish(1)

KEYWORDS
       database, option, priority, retrieve



Tk                                                                   option(n)
