This function uses the mc5p or mc4 and mc5 capabilities,
if they are present, to ship given data to a printer attached to the terminal.
Note that the mcprint code has no way to do flow control with the printer
or to know how much buffering it has. Your application is responsible for
keeping the rate of writes to the printer below its continuous throughput rate
(typically about half of its nominal cps rating). Dot-matrix printers and
6-page-per-minute lasers can typically handle 80cps, so a good conservative
rule of thumb is to sleep for a second after shipping each 80-character line.
RETURN VALUE
The mcprint function returns ERR if the write operation aborted
for some reason. In this case, errno will contain either an error associated
with write(2) or one of the following:
ENODEV
Capabilities for printer redirection do not exist.
ENOMEM
Couldn't allocate sufficient memory to buffer the printer write.
When mcprint succeeds, it returns the number of characters actually
sent to the printer.
PORTABILITY
The mcprint call was designed for ncurses(3X), and is not found
in SVr4 curses, 4.4BSD curses, or any other previous version of curses.
BUGS
Padding in the mc5p, mc4 and mc5 capabilities will not be
interpreted.
