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 com-
       mand 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  data-
       base  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 (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)