publish a char [closed]

edit

hey community, im a ROS beginner, and my question is how can i publish a char manualy in a rostopic? i have published a string with

rostopic pub -1 my_topic std_msgs/String x

but the comand

rostopic pub -1 my_topic std_msgs/Char x

fails

edit:

when i try:

fhduser@fhduser:~/catkin_ws/src/sekuria$ rostopic pub -1 my_topic std_msgs/Char a

i get: [WARN] [WallTime: 1391591690.683859] Inbound TCP/IP connection failed: global name '_x' is not defined

when i try:

fhduser@fhduser:~/catkin_ws/src/sekuria$ rostopic pub -1 my_topic std_msgs/Char data: a

i get:

ERROR: Too many arguments:

• Given: [{'data': None}, 'a']

• Expected: ['data']

Args are: [data]