.B read(fildes, buffer, nbytes)
A file descriptor is a word
returned from a successful
bytes into which the input will be placed.
bytes will be read; for example
if the file refers to a typewriter at most one line
In any event the number of characters read is returned.
If the returned value is 0, then
end-of-file has been reached.
If very large data files are to be accessed randomly, see
open(2), creat(2), dup(2), pipe(2), vread(2)
0 is returned when the end of the file has been reached.
If the read was otherwise unsuccessful
physical I/O errors, bad buffer address,
file descriptor not that of
.B sys read; buffer; nbytes