VMS Help TCPIP Services, Programming Interfaces, Sockets API, read(), Description  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    If the end of file is not reached, the read() function returns
    nbytes. If the end of file occurs during the read() function, it
    returns the number of bytes read.
    Upon successful completion, read() returns the number of bytes
    actually read and placed in the buffer.
    Related Functions
    See also socket().