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=head1 NAME



B<XPAServer: The XPA Server-side Programming Interface>



=head1 SYNOPSIS




A description of the XPA server-side programming interface.



=head1 DESCRIPTION



B<Introduction to XPA Server Programming>

Creating an XPA server is easy: you generally only need to call the
XPANew() subroutine to define a named XPA access point and set up the
send and receive callback routines.  You then enter an event loop such
as XPAMainLoop() to field XPA requests.

  #include <xpa.h>

  XPA XPANew(char *class, char *name, char *help,
      int (*send_callback)(), void *send_data, char *send_mode,
      int (*rec_callback)(),  void *rec_data,  char *rec_mode);

  XPA XPACmdNew(char *class, char *name);

  XPACmd XPACmdAdd(XPA xpa,
         char *name, char *help,
         int (*send_callback)(), void *send_data, char *send_mode,
         int (*rec_callback)(),  void *rec_data,  char *rec_mode);

  void XPACmdDel(XPA xpa, XPACmd cmd);

  XPA XPAInfoNew(char *class, char *name,
      int (*info_callback)(), void *info_data, char *info_mode);

  int XPAFree(XPA xpa);

  void XPAMainLoop(void);

  int XPAPoll(int msec, int maxreq);

  void XPAAtExit(void);

  void XPACleanup(void);



B<Introduction>

To use the XPA application programming interface, a software developer
generally will include the xpa.h definitions file:

  #include <xpa.h>

in the software module that defines or accesses an XPA access point, and
then will link against the libxpa.a library:

  gcc -o foo foo.c libxpa.a

XPA has been compiled using both C and C++ compilers.


A server program generally defines an XPA access point by calling the
XPANew() routine and specifies "send" and/or "receive" callback
procedures to be executed by the program when an external process
either sends data or commands to this access point or requests data or
information from this access point. A program also can define several
sub-commands for a single access point by calling XPACmdNew() and
XPACmdAdd() instead.  Having defined one or more public access points
in this way, an XPA server program enters its usual event loop (or
uses the standard XPA event loop).




=head1 SEE ALSO



See xpa(n) for a list of XPA help pages


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