@need 3200

@node A VU Name Handler for Standard Input and Output
@chapter A VU Name Handler for Standard Input and Output

These functions provide a VU namespace handler for file names matching
the regexp:

@example
@group
             ^-$
@end group
@group
@end group
@end example

When opened for @code{O_RDONLY} access, @code{"-"} refers to descriptor @code{0}.


When opened for @code{O_WRONLY} access, @code{"-"} refers to descriptor @code{1}.


The file @code{"-"} may not be opened for @code{O_RDWR} access.

@sp 1
@need 1750
@noindent
@b{* Function} @code{vu_push_dash_handler}@fuindex vu_push_dash_handler
@*
@example
@group
void vu_push_dash_handler (int is_optional);
@end group
@group
@end group
@end example

Establish a VU namespace handler for file-names matching the
regexp:

@example
@group
             ^-$
@end group
@group
@end group
@end example

When opened for @code{O_RDONLY} access, @code{"-"} refers to descriptor @code{0}.


When opened for @code{O_WRONLY} access, @code{"-"} refers to descriptor @code{1}.


The file @code{"-"} may not be opened for @code{O_RDWR} access.


If the flag @code{is_optional} is @code{0}, the namespace handler is simply
installed.  If it is not @code{0}, the handler is registered under the
name @code{"fd"}, but not installed.  


(See @strong{vu_enable_optional_name_handler} in @ref{Establishing VU Handlers}.)




