ROS实践（4）-消息服务

一 编辑msg文件，并编译

root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# cd ~/dev/ root@yangkai04-Inspiron-3650:~/dev# ls rosbook root@yangkai04-Inspiron-3650:~/dev# cd rosbook/ root@yangkai04-Inspiron-3650:~/dev/rosbook# ls chapter2_tutorials root@yangkai04-Inspiron-3650:~/dev/rosbook# cd chapter2_tutorials/ root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# ls bin  build  CMakeLists.txt  include  mainpage.dox  Makefile  manifest.xml  src root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# ls bin  build  CMakeLists.txt  include  mainpage.dox  Makefile  manifest.xml  src root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# mkdir msg root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# ls bin    CMakeLists.txt  mainpage.dox  manifest.xml  src build  include         Makefile      msg root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# cd msg/ root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials/msg# vim chapter2_msg1.msg int32 A int32 B int32 C root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials/msg# rosmake chapter2_tutorials [ rosmake ] Results:                                                             [ rosmake ] Built 25 packages with 0 failures.                                   [ rosmake ] Summary output to directory                                          [ rosmake ] /root/.ros/rosmake/rosmake_output-20161109-190250   root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials/msg# rosmsg show chapter2_tutorials/chapter2_msg1 int32 A int32 B int32 C root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials/msg# rosed chapter2_tutorials CMakeLists.txt osbuild_genmsg()解注释

二 编辑svr文件

root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials/msg# cd .. root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# mkdir srv root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# vim srv/chapter2_srv1.srv int32 A int32 B int32 C --- int32 sum root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# rosed chapter2_tutorials CMakeLists.txt rosbuild_gensrv()解注释 root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# rosmake chapter2_tutorials [ rosmake ] Results:                                                             [ rosmake ] Built 25 packages with 0 failures.                                   [ rosmake ] Summary output to directory                                          [ rosmake ] /root/.ros/rosmake/rosmake_output-20161109-190846   root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# rossrv show chapter2_tutorials/chapter2_srv1 int32 A int32 B int32 C --- int32 sum root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials#

三 添加代码并编译

root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials/src# pwd /root/dev/rosbook/chapter2_tutorials/src root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials/src# cp /home/yangkai04/Documents/Learning\ ROS\ for\ Robotics\ Programming\ 1448OS_Code/1448OS_02_Code/chapter2_tutorials/src/example2_* . root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# rosmake chapter2_tutorials [ rosmake ] Results:                                                             [ rosmake ] Built 25 packages with 0 failures.                                   [ rosmake ] Summary output to directory                                          [ rosmake ] /root/.ros/rosmake/rosmake_output-20161109-191544 修改CMakefile root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# rosed chapter2_tutorials CMakeLists.txt rosbuild_add_executable(example2_a src/example2_a.cpp) rosbuild_add_executable(example2_b src/example2_b.cpp) root@yangkai04-Inspiron-3650:~/dev/rosbook/chapter2_tutorials# rosmake chapter2_tutorials

四 启动

terminal1

root@yangkai04-Inspiron-3650:/home/yangkai04# roscore

terminal2

root@yangkai04-Inspiron-3650:/home/yangkai04# rosrun chapter2_tutorials example2_a [ INFO] [1478690632.264029358]: Ready to add 3 ints.

terminal3

root@yangkai04-Inspiron-3650:/home/yangkai04# rosrun chapter2_tutorials example2_b [ INFO] [1478690678.339046946]: usage: add_3_ints_client A B C root@yangkai04-Inspiron-3650:/home/yangkai04# rosrun chapter2_tutorials example2_b 1 3 4 [ INFO] [1478690687.261165534]: Sum: 8

terminal2

root@yangkai04-Inspiron-3650:/home/yangkai04# rosrun chapter2_tutorials example2_a [ INFO] [1478690632.264029358]: Ready to add 3 ints. [ INFO] [1478690687.260884068]: request: A=140733193388033, B=140733193388035 C=4 [ INFO] [1478690687.260910991]: sending back response: [140733193388040]

五 代码

example2_a.cpp

include "ros/ros.h"
#include "chapter2_tutorials/chapter2_srv1.h"

bool add(chapter2_tutorials::chapter2_srv1::Request  &req,
         chapter2_tutorials::chapter2_srv1::Response &res)
{
  res.sum = req.A + req.B + req.C;
  ROS_INFO("request: A=%ld, B=%ld C=%ld", (int)req.A, (int)req.B, (int)req.C);
  ROS_INFO("sending back response: [%ld]", (int)res.sum);
  return true;
}

int main(int argc, char **argv)
{
  ros::init(argc, argv, "add_3_ints_server");
  ros::NodeHandle n;

  ros::ServiceServer service = n.advertiseService("add_3_ints", add);
  ROS_INFO("Ready to add 3 ints.");
  ros::spin();

  return 0;
}

example2_b.cpp

#include "ros/ros.h"
#include "chapter2_tutorials/chapter2_srv1.h"
#include <cstdlib>

int main(int argc, char **argv)
{
  ros::init(argc, argv, "add_3_ints_client");
  if (argc != 4)
  {
    ROS_INFO("usage: add_3_ints_client A B C ");
    return 1;
  }

  ros::NodeHandle n;
  ros::ServiceClient client = n.serviceClient<chapter2_tutorials::chapter2_srv1>("add_3_ints");
  chapter2_tutorials::chapter2_srv1 srv;
  srv.request.A = atoll(argv[1]);
  srv.request.B = atoll(argv[2]);
  srv.request.C = atoll(argv[3]);
  if (client.call(srv))
  {
    ROS_INFO("Sum: %ld", (long int)srv.response.sum);
  }
  else
  {
    ROS_ERROR("Failed to call service add_two_ints");
    return 1;
  }

  return 0;
}