Sometimes a program may only require a directory name from the user. There
is another variation on asl.library's file requester that allows this.
The ASL_ExtFlags1 tag contains a flag bit to toggle this option. If the
FIL1F_NOFILES flag of ASL_ExtFlags1 is set, the requester will appear
without a string gadget for file names and will display only directory
names in the scrolling list gadget. When aslrequest() (or aslrequesttags()
) returns successfully, the rf_Dir field of the filerequester structure
contains the name of the directory the user selected.

Another flag defined for ASL_ExtFlags1 is FIL1F_MATCHDIRS. If file pattern
matching is on (see the filf_patgad flag for asl_funcflags, setting
FIL1F_MATCHDIRS tells the file requester to pattern match directory names
as well as file names.  Of course, if both of these ASL_ExtFlags1 flags
are set, the requester will only pattern match directory names.