NAME¶
XPA - Public Access to Data and Algorithms
SYNOPSIS¶
This document is the Table of Contents for XPA.
DESCRIPTION¶
The XPA messaging system provides seamless communication between many kinds of
Unix programs, including X programs and Tcl/Tk programs. It also provides an
easy way for users to communicate with XPA-enabled programs by executing XPA
client commands in the shell or by utilizing such commands in scripts. Because
XPA works both at the programming level and the shell level, it is a powerful
tool for unifying any analysis environment: users and programmers have great
flexibility in choosing the best level or levels at which to access XPA
services, and client access can be extended or modified easily at any time.
A program becomes an XPA-enabled server by defining named points of public
access through which data and commands can be exchanged with other client
programs (and users). Using standard TCP sockets as a transport mechanism, XPA
supports both single-point and broadcast messaging to and from these servers.
It supports direct communication between clients and servers, or indirect
communication via an intermediate message bus emulation program. Host-based
access control is implemented, as is as the ability to communicate with XPA
servers across a network.
XPA implements a layered interface that is designed to be useful both to
software developers and to users. The interface consists of a library of XPA
client and server routines for use in C/C++ programs and a suite of high-level
user programs built on top of these libraries. Using the XPA library, access
points can be added to Tcl/Tk programs, Xt programs, or to Unix programs that
use the XPA event loop or any event loop based on
select(). Client
access subroutines can be added to any Tcl/Tk, Xt, or Unix program. Client
access also is supported at the command line via a suite of high-level
programs.
Choose from the following topics:
- •
- Introduction to XPA [xpaintro(7)]
- •
- Access Point Names and Templates [xpatemplate(7)]
- •
- Getting Common Information About Access Points
[xpacommon(7)]
- •
- Communication Methods [xpamethod(7)]
- •
- Communication Between Hosts [xpainet(7)]
- •
- Distinguishing Users [xpausers(7)]
- •
- XPA User Programs
- •
- XPA Server Routines
- •
- XPANew: define a new access point [ xpanew(3)]
- •
- XPACmdNew: define a new command access point [
xpacmdnew(3)]
- •
- XPACmdAdd: add a command [ xpacmdadd(3)]
- •
- XPACmdDel: delete a command [ xpacmddel(3)]
- •
- XPAInfoNew: define an info access point [
xpainfonew(3)]
- •
- XPAFree: free an access point [ xpafree(3)]
- •
- XPAMainLoop: event loop for select server [
xpamainloop(3)]
- •
- XPAPoll: poll for XPA events [ xpapoll(3)]
- •
- XPACleanup: release reserved XPA memory [
xpacleanup(3)]
- •
- XPA Server Macros: accessing structure internals [
xpamacros(3)]
- •
- XPA Race Conditions: how to avoid them [
xparace(3)]
- •
- XPA Out of Memory (OOM) errors [ xpaoom(3)]
- •
- XPA Client Routines
- •
- XPAOpen: open a persistent client connection [
xpaopen(3)]
- •
- XPAClose: close persistent client connection [
xpaclose(3)]
- •
- XPAGet: get data [ xpaget(3)]
- •
- XPASet: send data or commands [ xpaset(3)]
- •
- XPAInfo: send an info alert [ xpainfo(3)]
- •
- XPAGetFd: get data and write to an fd [
xpagetfd(3)]
- •
- XPASetFd: read data from and fd and send [
xpasetfd(3)]
- •
- XPANSLookup: look up an access point [
xpanslookup(3)]
- •
- XPAAccess: get access info [ xpaaccess(3)]
- •
- The XPA/Xt Interface: Xt interface to XPA [xpaxt(7)]
- •
- The XPA/Tcl Interface: Tcl interface to XPA
[xpa(3tcl)]
- •
- Tailoring the XPA Environment
- •
- Miscellaneous
- •
- Where to Find Example/Test Code
- •
- User Changes Between XPA 1.0 and 2.0
- •
- API Changes Between XPA 1.0 and 2.0
- •
- What Does XPA Stand For, Anyway?
