1e41f4b71Sopenharmony_ci# Common Event Manager 2e41f4b71Sopenharmony_ci 3e41f4b71Sopenharmony_ciThe Common Event Manager enables you to print common event information and publish common events. It provides the common event debugging and testing capabilities, for example, printing all public event subscribers, sent public events, and recipients, and simulating public event release. 4e41f4b71Sopenharmony_ci 5e41f4b71Sopenharmony_ci> **NOTE** 6e41f4b71Sopenharmony_ci> 7e41f4b71Sopenharmony_ci> Before using this tool, you must obtain the <!--Del-->[<!--DelEnd-->hdc tool<!--Del-->](../../device-dev/subsystems/subsys-toolchain-hdc-guide.md)<!--DelEnd--> and run the hdc shell command. 8e41f4b71Sopenharmony_ci 9e41f4b71Sopenharmony_ci## Commands 10e41f4b71Sopenharmony_ci 11e41f4b71Sopenharmony_ci### help 12e41f4b71Sopenharmony_ci 13e41f4b71Sopenharmony_ci* Function 14e41f4b71Sopenharmony_ci 15e41f4b71Sopenharmony_ci Prints help information. 16e41f4b71Sopenharmony_ci 17e41f4b71Sopenharmony_ci* Method 18e41f4b71Sopenharmony_ci 19e41f4b71Sopenharmony_ci ``` 20e41f4b71Sopenharmony_ci cem help 21e41f4b71Sopenharmony_ci ``` 22e41f4b71Sopenharmony_ci 23e41f4b71Sopenharmony_ci### publish 24e41f4b71Sopenharmony_ci 25e41f4b71Sopenharmony_ci* Function 26e41f4b71Sopenharmony_ci 27e41f4b71Sopenharmony_ci Publishes a common event. 28e41f4b71Sopenharmony_ci 29e41f4b71Sopenharmony_ci* Method 30e41f4b71Sopenharmony_ci 31e41f4b71Sopenharmony_ci ``` 32e41f4b71Sopenharmony_ci cem publish [<options>] 33e41f4b71Sopenharmony_ci ``` 34e41f4b71Sopenharmony_ci 35e41f4b71Sopenharmony_ci The table below describes the available options. 36e41f4b71Sopenharmony_ci 37e41f4b71Sopenharmony_ci | Name | Description | 38e41f4b71Sopenharmony_ci | ------------ | ------------------------------------------ | 39e41f4b71Sopenharmony_ci | -e/--event | Name of the common event to publish. Mandatory. | 40e41f4b71Sopenharmony_ci | -o/--ordered | Indicates that the common event to publish is ordered. Optional. By default, non-ordered events are published. | 41e41f4b71Sopenharmony_ci | -c/--code | Result code of the common event. Optional. | 42e41f4b71Sopenharmony_ci | -d/--data | Data carried in the common event. Optional. | 43e41f4b71Sopenharmony_ci | -h/--help | Help information. | 44e41f4b71Sopenharmony_ci 45e41f4b71Sopenharmony_ci* Example 46e41f4b71Sopenharmony_ci 47e41f4b71Sopenharmony_ci ```bash 48e41f4b71Sopenharmony_ci # Publish a common event named testevent. 49e41f4b71Sopenharmony_ci cem publish --event "testevent" 50e41f4b71Sopenharmony_ci ``` 51e41f4b71Sopenharmony_ci 52e41f4b71Sopenharmony_ci  53e41f4b71Sopenharmony_ci 54e41f4b71Sopenharmony_ci ```bash 55e41f4b71Sopenharmony_ci # Publish an ordered common event named testevent. The result code of the event is 100 and the data carried is "this is data". 56e41f4b71Sopenharmony_ci cem publish -e "testevent" -o -c 100 -d "this is data" 57e41f4b71Sopenharmony_ci ``` 58e41f4b71Sopenharmony_ci 59e41f4b71Sopenharmony_ci  60e41f4b71Sopenharmony_ci 61e41f4b71Sopenharmony_ci### dump 62e41f4b71Sopenharmony_ci 63e41f4b71Sopenharmony_ci> **NOTE** 64e41f4b71Sopenharmony_ci> 65e41f4b71Sopenharmony_ci> The Common Event Manager has two editions: **eng** and **user**. The **dump** command can be used only in the **eng** edition. If it is used in the **user** edition, the message **error: user version cannot use dump** is reported. 66e41f4b71Sopenharmony_ci 67e41f4b71Sopenharmony_ci* Function 68e41f4b71Sopenharmony_ci 69e41f4b71Sopenharmony_ci Displays information about common events. 70e41f4b71Sopenharmony_ci 71e41f4b71Sopenharmony_ci* Method 72e41f4b71Sopenharmony_ci 73e41f4b71Sopenharmony_ci ``` 74e41f4b71Sopenharmony_ci cem dump [<options>] 75e41f4b71Sopenharmony_ci ``` 76e41f4b71Sopenharmony_ci 77e41f4b71Sopenharmony_ci The table below describes the available options. 78e41f4b71Sopenharmony_ci 79e41f4b71Sopenharmony_ci | Name | Description | 80e41f4b71Sopenharmony_ci | ---------- | -------------------------------------------- | 81e41f4b71Sopenharmony_ci | -a/--all | Information about all common events that have been sent since system startup.| 82e41f4b71Sopenharmony_ci | -e/--event | Information about a specific event. | 83e41f4b71Sopenharmony_ci | -h/--help | Help information. | 84e41f4b71Sopenharmony_ci 85e41f4b71Sopenharmony_ci* Example 86e41f4b71Sopenharmony_ci 87e41f4b71Sopenharmony_ci ```bash 88e41f4b71Sopenharmony_ci # Display details of a common event named testevent. 89e41f4b71Sopenharmony_ci cem dump -e "testevent" 90e41f4b71Sopenharmony_ci ``` 91e41f4b71Sopenharmony_ci 92e41f4b71Sopenharmony_ci  93
