File filter - %ft[name][filter]
%ft is used to change the default filter for subsequent use of the FILE_OPENR
and FILE_OPENW call-back functions (see
FILE_OPENR). The information is used in the standard Windows dialog
displayed by these call-back functions. Two standard character strings are
required after %ft. The first is the name of the filter (e.g. 'Executable
files'). The second is the specification (e.g. '*.EXE').
If the grave accent modifier is used with %ft, the filter information replaces
the existing information, otherwise it is added at the front of any existing
filter information. The default filter selects all files.
You cannot change the name and filters dynamically by using %fs and %ft with
variable character strings. See get_filtered_file@.