doc/src/user/example1.im

.if false
==================================================================================
    Copyright (c) 2020 Nokia
    Copyright (c) 2020 AT&T Intellectual Property.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
==================================================================================
.fi


&h2(RMR Dump xAPP)
The RMR dump application is an example built on top of the C++ xApp framework to both
illustrate the use of the framework, and to provide a useful diagnostic tool when
testing and troubleshooting xApps.
&space

The RMR dump xApp isn't a traditional xApp inasmuch as its goal is to listen for message
types and to dump information about the messages received to the TTY much as &cw(tcpdump)
does for raw packet traffic.
The full source code, and Makefile, are in the &cw(examples) directory of the C++ framework repo.
&space

When invoked, the RMR dump program is given one or more message types to listen for.
A callback function is registered for each, and the framework &cw(Run()) function is invoked
to drive the process.
For each recognised message, and depending on the verbosity level supplied at program start,
information about the received message(s) is written to the TTY.
If the forwarding option, -f, is given on the command line, and an appropriate route table is
provided, each received message is forwarded without change.
This allows for the insertion of the RMR dump program into a flow, however if the ultimate
receiver of a message needs to reply to that message, the reply will not reach the original
sender, so RMR dump is not a complete "middle box" application.
&space

The following is the code for this xAPP. Several functions, which provide logic unrelated to
the framework, have been omitted. The full code is in the framework repository.
&half_space

&space
&indent
.** pull in the code from the example directory
&ex_start
.im  j=start-example ../../../examples/rmr_dump.cpp
&ex_end
&fig_cen( Simple callback application. )
&uindent