    READ(II)                      8/5/73                     READ(II)

    NAME
         read - read from file

    SYNOPSIS
         (read = 3.)
         (file descriptor in r0)
         sys read; buffer; nbytes

         read(fildes, buffer, nbytes)
         char *buffer;

    DESCRIPTION
         A file descriptor is a word returned from a successful open,
         creat, dup, or pipe call.  Buffer is the location of  nbytes
         contiguous bytes into which the input will be placed.  It is
         not guaranteed that all nbytes bytes will be read; for exam-
         ple if the file refers to a typewriter at most one line will
         be returned.  In any event the number of characters read  is
         returned (in r0).

         If  the  returned  value  is  0,  then  end-of-file has been
         reached.

    SEE ALSO
         open(II), creat(II), dup(II), pipe(II)

    DIAGNOSTICS
         As mentioned, 0 is returned when the end  of  the  file  has
         been  reached.   If  the read was otherwise unsuccessful the
         error bit (c-bit) is set.  Many conditions can  generate  an
         error: physical I/O errors, bad buffer address, preposterous
         nbytes, file descriptor not that of an input file.  From  C,
         a -1 return indicates the error.

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