## For instruction on writing tutorials
## http://www.ros.org/wiki/WritingTutorials
####################################
##FILL ME IN
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## for the canned note of "This tutorial assumes that you have completed the previous tutorials:" just add the links
## note.0= [[ROS/Tutorials/InstallingandConfiguringROSEnvironment| installing ROS]]
## descriptive title for the tutorial
## title = Writing a Simple Publisher and Subscriber (C++) (plain cmake)
## multi-line description to be displayed in search
## description = This tutorial covers how to write a publisher and subscriber node in C++ using plain cmake (i.e., not [[catkin]]).
## the next tutorial description (optional)
## next =
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## level= BeginnerCategory
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<<IncludeCSTemplate(TutorialCSHeaderTemplate)>>

<<TableOfContents(4)>>

{{{#!wiki blue/solid
'''Note:''' Be sure that you have already [[ROS/Installation|installed ROS]] and remember that you must [[ROS/Tutorials/InstallingandConfiguringROSEnvironment#Managing_Your_Environment|source the appropriate setup file]] in every shell you create.
}}}
== Making a directory in which to work ==
To help keep yourself organized, make a directory in which to work. You can use any name; we'll just call it `pubsub`:

{{{
mkdir -p pubsub
cd pubsub
}}}
== Writing the Publisher Node ==
<<Include(roscpp_tutorials/Tutorials/WritingPublisherSubscriber,,from="##startpubintro",to="##endpubintro")>>

=== The Code ===
Create a file named `talker.cpp` within the `pubsub` directory and paste the following inside it:

<<Include(roscpp_tutorials/Tutorials/WritingPublisherSubscriber,,from="##startpubcode",to="##endpubcode")>>

== Writing the Subscriber Node ==
=== The Code ===
Create a file named `listener.cpp` within the `pubsub` directory and paste the following inside it:

<<Include(roscpp_tutorials/Tutorials/WritingPublisherSubscriber,,from="##startsubcode",to="##endsubcode")>>

== Building your nodes ==
You need to tell `cmake` how to build (compile and link) your C++ code. Create a file named `CMakeLists.txt` in the `pubsub` directory and paste the following inside it:

<<GetCode(https://raw.githubusercontent.com/gerkey/ros1_external_use/master/ros1_comms/CMakeLists.txt,xml)>>

Build your nodes in a subdirectory of `pubsub` named `build` using the standard `cmake` sequence:

{{{
mkdir -p build
cd build
cmake ..
make
}}}
<<Include(roscpp_tutorials/Tutorials/WritingPublisherSubscriber,,from="##startroscore",to="##endroscore")>>

Now everything is set to run talker/listener. Open a new shell, go to your `pubsub` directory and type:

{{{
./build/talker
}}}
Now in the original shell type:

{{{
./build/listener
}}}
<<Include(roscpp_tutorials/Tutorials/WritingPublisherSubscriber,,from="##starttalkerlistener",to="##endtalkerlistener")>>

== Using roslaunch/rosrun ==
In order for roslaunch to find launch files associated with this node, you'll need to have a package.xml file located next to a `launch` folder which contains launch files, and you'll need to make sure that the path to that package.xml file can be found in the environment variable ROS_PACKAGE_PATH. The package.xml file just needs a valid name field, i.e. it can be as simple as

{{{
<?xml version="1.0"?>
<package>
  <name>my_pkg_name</name>
</package>
}}}
In order for rosrun to be able to detect this executable, you'll need to install your executable into a folder structure that look like this:

 * The root folder contains an empty .catkin file
 * The root folder appears in the CMAKE_PREFIX_PATH environment variable
 * The root folder contains either a `libexec` or `share` folder which contains a folder named after the package, which then contains your executable

That last one was a little wordy. Here's what the directory will look like:

{{{
/path/to/installation_folder
├── .catkin <- empty file
└── libexec <- could be 'share' instead of 'libexec', both are valid
    └── my_pkg_name
        └── my_executable
}}}
And /path/to/installation_folder needs to be appear in CMAKE_PREFIX_PATH. You may find it helpful to create your own setup.sh file to autopopulate the ROS_PACKAGE_PATH and CMAKE_PREFIX_PATH variables.

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## TutorialCategory
## FILL IN THE STACK TUTORIAL CATEGORY HERE