# catkin:

```
make source
catkin_make # -or- catkin_make --source src

git env vars:
source devel/setup.bash

rospack find [package]
roscd # ros cd
rosls # ros ls
```


# other ROS stuff

```sh
rosnode list
rosnode ping turtlesim

rosrun roscore
rosrun turtlesim turtlesim_node

rosrun rqt_graph rqt_graph # make a subscriber graph
rosrun rqt_plot rqt_plot


rostopic -h
  rostopic bw     display bandwidth used by topic
  rostopic echo   print messages to screen
  rostopic hz     display publishing rate of topic
  rostopic list   print information about active topics
  rostopic pub    publish data to topic
  rostopic type   print topic type

rostopic echo [topic]
rostopic type [topic]
rostopic type /turtle1/cmd_vel
# --> geometry_msgs/Twist
# wtf is "geometry_msgs/Twist"? let's see:
rosmsg show geometry_msgs/Twist
# -->
  geometry_msgs/Vector3 linear
    float64 x
    float64 y
    float64 z
  geometry_msgs/Vector3 angular
    float64 x
    float64 y
    float64 z

rostopic pub [topic] [msg_type] [args] # publishes data on currently advertised topic
rostopic pub -1 turtle1/cmd_vel geometry_msgs/Twist -- '[2.0, 0.0, 0.0]' '[0.0, 0.0, 1.8]'
# -1: only publish one message and exit
# -- what follows now are args

rosservice
rosservice call /spawn 2 2 0.2 "WOW"

rosparam # allows you to store and manipulate ros parameter server data
 --> integer, float, dictionary, list, boolean.  YAML format
rosparam [set|get|load|dump|delete|list]
rosparam list
rosparam [dump|load] <filename.yaml> [OPTIONAL: namespace]

roslaunch nolan_tutorial turtlemimic.launch

rosmsg show <message_name>
rosmsg show nolan_tutorial/num
rossrv show "


```