recvfrom(2)                DG/UX 4.30                 recvfrom(2)



     NAME
          recvfrom - Receive a message from a socket.

     SYNOPSIS
          #include <sys/socket.h>

          int   recvfrom  (s, buf, len, user_flags, from, fromlen)
          int             s;
          char *          buf;
          int             len;
          int             user_flags;
          struct sockaddr *from;
          int *           fromlen;

     PARAMETERS
          s              File descriptor of socket to receive a
                         message from.


          buf            Buffer for message.


          len            Length of buffer.


          user_flags     Flags for transfer.


          from           Structure to hold sender's name.


          fromlen        On input contains the number of bytes
                         available for the sender's name; updated to
                         indicate the number of bytes returned.

     DESCRIPTION
          This call is identical to the recv call with the addition of
          returning the name of the socket from which the message was
          sent.  When using recvfrom on connected sockets the <from>
          and <fromlen> arguments will be undefined.  When reading
          from datagram sockets, messages that are longer than the
          buffer are truncated. See recv(2) for additional information
          about the socket receive mechanism.

     ACCESS CONTROL
          None.

     RETURN VALUE
          These calls return the number of bytes received.


          1..<len>       Number of bytes transferred.



     Licensed material--property of copyright holder(s)         Page 1

     recvfrom(2)                DG/UX 4.30                 recvfrom(2)



          -1             An error occurred.  Errno is set to indicate
                         the error.

     EXCEPTIONS
          Errno may be set to one of the following error codes:


          EBADF          The argument <s> is not an active valid
                         descriptor.


          ENOTSOCK       The argument <s> is not a socket.


          EAGAIN         The socket is marked non-blocking and the
                         receive operation would block.


          EINTR          The receive was interrupted by delivery of a
                         signal before any data was available for the
                         receive.


          EFAULT         The data was specified to be received into a
                         non-existent or protected part of the process
                         address space.


          EINVAL         Bad argument.

     SEE ALSO
          The related manual sections:  read(2), recv(2), send(2),
          socket(2).






















     Licensed material--property of copyright holder(s)         Page 2