Openvms UDP programming using sys$qio

[Max Bruno Jarvis]

I'm new to network programming on OpenVMS. I need to write a simple application to allow two adjacent OpenVMS computers to exchange datagrams via Ethernet. Datagrams can go both ways and I need to use ASTs for read completions, so can't use the sockets API. I'm finding the HP manual very confusing, for example I'm not really clear whether I need a 'socket' or not. Does anybody have any sample source code (in C, using sys$qio) for sending UDP datagrams between two OpenVMS systems? Sounds easy but I'm not finding it so.

[Walter Miller_1 · Accepted solution]

If you are using HP's tcpip stack you can usually find example programs in sys$common:syshelp.examples.ucx] or sys$common:syshelp.examples.tcpip] depending version of tcpip you are using and if whoever installed the product chose to include the example files.

[Max Bruno Jarvis]

I can't find a directory named syshelp on the disk at all. These are Integrity servers which came with OpenVMS and TCPIP already installed.

[Duncan Morris]

Minor correction to Walter's posting:

Directory SYS$COMMON:[SYSHLP.EXAMPLES.TCPIP]

so SYSHLP not SYSHELP.


Duncan

[Max Bruno Jarvis]

Aha, now I've found SYSHLP files, my thanks to both responders. Will study the files forthwith.

[Richard J Maher]

Hi Max,

The examples are easiest found using the old UCX$EXAMPLES or new TCPIP$EXAMPLES logical names.

In case it is of any interest to what you are doing with UDP, there is a Java Applet on the following page that receives messages from a VMS server asynchronously and outputs to a web page: -
http://deathrow.vistech.net/~tier3/tier3pager.html

Once youve got it up you need to logon the the deathrow.vistech.net and: -
$run DISK$USERS:[USERS.TIER3.WEB]demo_udp_msg

Then enter the IP address of your client.

Regards Richard Maher

[Ananth S]

dir tcpip$examples:*udp*qio*.*
These are the example programs.