HP 9000 Series 300 Tutorials Manual page 269

• All attributes forming the attrs argument are combined using the
logical OR operator to create a single 32-bit word containing all
attributes in the argument. For example, the three attribute words
00000100000000000000000000000000,
00010000000000000000000000000000,
and
00000010000000000000000000000000
are combined to form
00010110000000000000000000000000 which identifies the new
attributes.
• Three things can be done with the new attributes word. It can be
used as the new current attributes attrset or wattrset); or the new
attributes can be added to any currently active attributes (attron or
wattron), or deleted from the currently active attributes (attroff or
wattroff).
• If attrset (or wattrset) was called, the routine stores the new
attributes in the current attributes variable and returns. The previous
set of current attributes is destroyed.
• If attron (or wattron) was called, the routine performs a logical OR
of the current attributes with the new attributes, then places the result
in the current attributes variable and returns. The revised current
attributes variable contains all previously active attributes plus the new
attributes.
• If attroff (or wattroff) was called, the routine inverts the new
attributes, performs a logical AND on the inverted new attributes and
the current attributes, then places the result in the current attributes
variable and returns. The altered current attributes variable contains
all previously active attributes except those specified in the call, which
are now disabled.
• standout and wstandout obtain their highlighting attributes from the
terminfo data base, then perform the same operation as attron prior
to returning.
• standend and wstandend disable all attributes then return. They are
equivalent to attrset(O) and attrset
(A_NORMAL).
Program Operation 3-5