.B write(fildes, buffer, nbytes)
A file descriptor is a word returned from a
bytes which are written on the output file.
The number of characters actually written is returned.
It should be regarded as an error
if this is not the same as requested.
Writes which are multiples
of 1024 characters long and begin on a 1024-byte boundary
are more efficient than any others.
creat(2), open(2), pipe(2)
\-1 on error: bad descriptor, buffer address, or
count; physical I/O errors.
.B sys write; buffer; nbytes