| .. zephyr:code-sample:: logging |
| :name: Logging |
| :relevant-api: log_api log_ctrl |
| |
| Output log messages to the console using the logging subsystem. |
| |
| Overview |
| ******** |
| A simple application that demonstrates use of logging subsystem. It demonstrates |
| main features: severity levels, timestamping, module level filtering and |
| instance level filtering. It also showcases logging capabilities in terms of |
| performance. |
| |
| Building and Running |
| ******************** |
| |
| This project outputs multiple log message to the console. It can be built and |
| executed on QEMU as follows: |
| |
| .. zephyr-app-commands:: |
| :zephyr-app: samples/subsys/logging/logger |
| :host-os: unix |
| :board: qemu_x86 |
| :goals: run |
| :compact: |
| |
| |
| Sample Output |
| ============= |
| |
| .. code-block:: console |
| |
| Module logging showcase. |
| [00:00:00.106,051] <inf> sample_module: log in test_module 11 |
| [00:00:00.106,054] <inf> sample_module: Inline function. |
| Disabling logging in the sample_module module |
| Function called again but with logging disabled. |
| Instance level logging showcase. |
| [00:00:00.106,200] <inf> sample_instance.inst1: Inline call. |
| [00:00:00.106,204] <inf> sample_instance.inst1: counter_value: 0 |
| [00:00:00.106,209] <wrn> sample_instance.inst1: Example of hexdump: |
| 01 02 03 04 |.... |
| [00:00:00.106,214] <inf> sample_instance.inst2: Inline call. |
| [00:00:00.106,218] <inf> sample_instance.inst2: counter_value: 0 |
| [00:00:00.106,223] <wrn> sample_instance.inst2: Example of hexdump: |
| 01 02 03 04 |.... |
| Changing filter to warning on sample_instance.inst1 instance. |
| [00:00:00.106,297] <wrn> sample_instance.inst1: Example of hexdump: |
| 01 02 03 04 |.... |
| [00:00:00.106,302] <inf> sample_instance.inst2: Inline call. |
| [00:00:00.106,307] <inf> sample_instance.inst2: counter_value: 1 |
| [00:00:00.106,311] <wrn> sample_instance.inst2: Example of hexdump: |
| 01 02 03 04 |.... |
| Disabling logging on both instances. |
| Function call on both instances with logging disabled. |
| String logging showcase. |
| [00:00:01.122,316] <inf> main: Logging transient string:transient_string |
| Severity levels showcase. |
| [00:00:01.122,348] <err> main: Error message example. |
| [00:00:01.122,352] <wrn> main: Warning message example. |
| [00:00:01.122,355] <inf> main: Info message example. |
| Logging performance showcase. |
| [00:00:02.151,602] <inf> main: performance test - log message 0 |
| Estimated logging capabilities: 42000000 messages/second |
| Logs from external logging system showcase. |
| [00:00:03.165,977] <err> ext_log_system: critical level log |
| [00:00:03.165,991] <err> ext_log_system: error level log, 1 arguments: 1 |
| [00:00:03.166,006] <wrn> ext_log_system: warning level log, 2 arguments: 12 |
| [00:00:03.166,025] <inf> ext_log_system: notice level log, 3 arguments: 105 |
| [00:00:03.166,044] <inf> ext_log_system: info level log, 4 arguments : 1 24 |
| |
| Exit QEMU by pressing :kbd:`CTRL+A` :kbd:`x`. |
