6.18-gdb,ros and roslaunch with gdb

6.18-gdb is a version of the GNU Debugger that is commonly used for debugging software programs. ROS (Robot Operating System) is a popular framework for building robotic systems, and roslaunch is a tool for launching multiple ROS nodes and coordinating their communication.

To use gdb with ROS and roslaunch, you can follow these steps:

1. Compile your ROS package with debug symbols by adding the "-g" flag to your catkin_make or catkin build command.

2. Launch your ROS nodes using roslaunch with the "--debug" flag. This will start your nodes in debug mode and allow gdb to attach to them.

3. In a separate terminal, start gdb and attach it to the running ROS nodes using the "attach" command. For example, if your node is called "my_node" and is running on port 11311, you can attach gdb to it with the following command:

   gdb -ex "target remote :11311" -ex "set follow-fork-mode child" -ex "set detach-on-fork off" -ex "break main" -ex "continue" my_node

4. Once gdb is attached to the node, you can set breakpoints, step through your code, and inspect variables just like you would with any other program.

Note that debugging ROS nodes with gdb can be complicated, especially if your nodes are distributed across multiple machines. In these cases, it may be easier to use ROS debugging tools like rqt_debug or the ROS Debugging Tool (RDT).