

          scancontext [option]
               This command manages file scan contexts.  A scan
               context is a collection of regular expressions and
               commands to execute when that regular expression
               matches a line of the file.  A context may also have a
               single default match, to be applied against lines that
               do not match any of the regular expressions.  Multiple
               scan contexts may be defined and they may be reused on
               multiple files.  A scan context is identified by a
               context handle.  The scancontext command takes the
               following forms:

          scancontext create
               Create a new scan context.  The scanmatch command is
               used to define patterns in the context.  A
               contexthandle is returned, which the Tcl programmer
               uses to refer to the newly created scan context in
               calls to the Tcl file scanning commands.

          scancontext delete contexthandle
               Delete the scan context identified by contexthandle,
               and free all of the match statements and compiled
               regular expressions associated with the specified
               context.
