ROS--7 Log信息

缺乏、安全感 2023-06-24 04:59 50阅读 0赞

rospy.loginfo('GoToPositionRequest Received - j1:%s, j2:%s', req.joint_1, req.joint_2)

By default all logging messages for a node are written to the node's log file which can be found in **`~/.ros/log`** or **`ROS_ROOT/log`** .

If **`roscore`**** i**s running, you can use **`roscd`** to find log file directory by opening a new terminal window and typing:

roscd log

In this directory, you should see directories from runs of your ROS code, along with a **`latest`** directory with log files from the most recent run.

# 7.1 Logging levels and outputs #

rospy.logdebug(...)
    rospy.loginfo(...)
    rospy.logwarn(...)
    rospy.logerr(...)
    rospy.logfatal(...)

All levels of logging messages are recorded in ROS log files, but some message levels may also be sent to Python **`stdout`**, Python** ****`stderr`**, or the ROS topic** ****`/rosout`**.

The **`loginfo`** messages are written to Python's **`stdout`**, while **`logwarn`**, **`logerr`**, and **`logfatal`** are written to Python's **`stderr`**** **by default. Additionally, **`loginfo`**, **`logwarn`**, **`logerr`**, and **`logfatal`** are written to `/rosout`.

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2x1dGVyZXNh_size_16_color_FFFFFF_t_70][]

More in [http://wiki.ros.org/rospy/Overview/Logging][http_wiki.ros.org_rospy_Overview_Logging]

# 7.2 Filtering and saving log messages from /rosout #

Note that for messages written to `/rosout`, you can see the messages in real time as your program is running by echoing:

rostopic echo /rosout

一般可以用grep来过滤有用信息

rostopic echo /rosout | grep insert_search_expression_here

rostopic echo /rosout | grep insert_search_expression_here > path_to_output/output.txt

# 7.3 Modifying message level sent to /rosout #

To do this you must set the **`log_level`** attribute within the **`rospy.init_node`**** **code.

For example, if you'd like to allow logdebug messages to be written to `/rosout`, that can be done as follows:

rospy.init_node('my_node', log_level=rospy.DEBUG)

# 7.4 Modifying display of messages sent to `stdout` and `stderr` #

It is also possible to change how messages to **`stdout`** and **`stderr`** are displayed or logged. Within a package's **`.launch`** file, the **`output`** attribute for a node tag can be set to `"screen"` or `"log"`. The following table summarizes how the different output options change the display of the node's `stdout `and **`stderr`** messages:

![20191220194905135.png][]

For example, setting **`output="screen"`** for the **`look_away`** node in **`robot_spawn.launch`** will display both **`stdout`** and **`stderr`** messages in the screen:

<node name="look_away" type="look_away" pkg="simple_arm" output="screen"/>

If the **`output`** attribute is left empty, the default is `"log"`.

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2x1dGVyZXNh_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20191220194441798.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2x1dGVyZXNh,size_16,color_FFFFFF,t_70
[http_wiki.ros.org_rospy_Overview_Logging]: http://wiki.ros.org/rospy/Overview/Logging
[20191220194905135.png]: https://img-blog.csdnimg.cn/20191220194905135.png