atp(3N)                                                   atp(3N)



NAME
     atp_open, atp_close - provide a AppleTalk Transaction
     Protocol (ATP) interface

SYNOPSIS
     #include <at/appletalk.h>
     #include <at/atp.h>

     int atp_open(socket)
     at_socket *socket;

     int atp_close(fd)
     int fd;

DESCRIPTION
     The ATP interface provides applications with access to the
     services of the AppleTalk Transaction Protocol, a transport
     layer protocol.

     These routines use the following structures, defined in
     <at/appletalk.h>.

     The atp_open routine opens an ATP AppleTalk socket and
     returns a file descriptor for use with the remaining ATP
     calls.

     socket
          A pointer to the DDP socket number to open.  If the
          AppleTalk socket number is 0, or if socket is NULL, a
          DDP socket is dynamically assigned.  If  non-NULL, the
          socket number is returned in socket.

     The atp_close routine closes the ATP AppleTalk socket
     identified by the file descriptor fd.

STATUS MESSAGES AND VALUES
     All routines return -1 on error with a detailed error code
     in errno.  For additional errors returned by the underlying
     DDP module, see ddp(3N).

     The error messages are:

     [EAGAIN]
          The request failed due to a temporary resource
          limitation; try again.  When this error occurs, no XO
          (``exactly-once'') transaction is initiated.

     [ENOENT]
          The request was an attempt to send a response to a
          nonexistent transaction.

     [ETIMEDOUT]



March 1993                                                      1

atp(3N)                                                   atp(3N)



          The request exceeded the maximum retry count.

FILES
     /usr/lib/libat.a
          Archive of object files for these and related routines
SEE ALSO
     ddp(3N), nbp(3N), pap(3N), rtmp(3N)

     Inside AppleTalk

     ``AppleTalk Programming Guide,'' in Network Applications
     Programming











































2                                                      March 1993