Talking to the ROS parameter server

YARP has no special support for the ROS parameter server, but can communicate with it via its network API.

Here is a command-line example:

yarp rpc /ros
>>setParam /demo foo 15
Response: 1 "parameter /foo set" 0
>>getParam /demo foo
Target disappeared, reconnecting...
Response: 1 "Parameter [/foo]" 15

From code, you could use a Bottle:

Network yarp;
Contact ros = Network::queryName("/ros");
printf("ROS available as %s\n", ros.toURI().c_str());
 
// set a parameter called "foo" to 15
Bottle cmd, reply;
cmd.addString("setParam");
cmd.addString("/demo");
cmd.addString("foo");
cmd.addInt32(15);
Network::write(ros,cmd,reply);
printf("reply to setParam is: %s\n", reply.toString().c_str());
 
// read "foo" back
cmd.clear();
cmd.addString("getParam");
cmd.addString("/demo");
cmd.addString("foo");
Network::write(ros,cmd,reply);
printf("reply to getParam is: %s\n", reply.toString().c_str());
printf("Stored value is hopefully %d\n", reply.get(2).asInt32());
return 0;

This should give:

ROS available as xmlrpc://127.0.0.1:11311
reply to setParam is: 1 "parameter /foo set" 0
reply to getParam is: 1 "Parameter [/foo]" 15
Stored value is hopefully 15