1e41f4b71Sopenharmony_ci# param 2e41f4b71Sopenharmony_ci 3e41f4b71Sopenharmony_ciThe param tool enables you to operate system parameters. It is valid only for standard-system devices. 4e41f4b71Sopenharmony_ci 5e41f4b71Sopenharmony_ci## Prerequisites 6e41f4b71Sopenharmony_ci 7e41f4b71Sopenharmony_ci* You have obtained the <!--Del-->[<!--DelEnd-->hdc tool<!--Del-->](../../device-dev/subsystems/subsys-toolchain-hdc-guide.md)<!--DelEnd--> to run hdc shell commands. 8e41f4b71Sopenharmony_ci* The device is properly connected. 9e41f4b71Sopenharmony_ci 10e41f4b71Sopenharmony_ci## Command Description 11e41f4b71Sopenharmony_ci 12e41f4b71Sopenharmony_ci | Command| Description| 13e41f4b71Sopenharmony_ci | ----------------- | ------------------------------------------ | 14e41f4b71Sopenharmony_ci | ls [-r] [name] | Displays the information about the system parameter that matches the given name. If **-r** is carried, the information is obtained based on the parameter permission. If **-r** is not carried, the information is directly obtained.| 15e41f4b71Sopenharmony_ci | get [name] | Obtains the value of the system parameter with the given name. If no name is specified, the values of all system parameters are returned.| 16e41f4b71Sopenharmony_ci | set name value | Sets the value for the system parameter with the given name.| 17e41f4b71Sopenharmony_ci | wait name [value] [timeout] | Waits for the system parameter with the given name to match the specified value. Fuzzy match is supported. For example, ***** indicates any value, and **val*** indicates matching of only the first three val characters. **timeout** indicates the waiting time, in seconds. If it is not set, the default value 30s is used.| 18e41f4b71Sopenharmony_ci | save | Persistently saves the parameters to the workspace.| 19e41f4b71Sopenharmony_ci 20e41f4b71Sopenharmony_ci## Example 21e41f4b71Sopenharmony_ci 22e41f4b71Sopenharmony_ci* To display information about the system parameter that matches a given name, run the following command: 23e41f4b71Sopenharmony_ci 24e41f4b71Sopenharmony_ci ```bash 25e41f4b71Sopenharmony_ci param ls [-r] [name] 26e41f4b71Sopenharmony_ci ``` 27e41f4b71Sopenharmony_ci **Usage Example** 28e41f4b71Sopenharmony_ci  29e41f4b71Sopenharmony_ci  30e41f4b71Sopenharmony_ci  31e41f4b71Sopenharmony_ci 32e41f4b71Sopenharmony_ci* To obtain the value of the system parameter with the given name, run the following command: 33e41f4b71Sopenharmony_ci 34e41f4b71Sopenharmony_ci ```bash 35e41f4b71Sopenharmony_ci param get [name] 36e41f4b71Sopenharmony_ci ``` 37e41f4b71Sopenharmony_ci **Usage Example** 38e41f4b71Sopenharmony_ci  39e41f4b71Sopenharmony_ci 40e41f4b71Sopenharmony_ci* To set the value for the system parameter with the given name, run the following command: 41e41f4b71Sopenharmony_ci 42e41f4b71Sopenharmony_ci ```bash 43e41f4b71Sopenharmony_ci param set name value 44e41f4b71Sopenharmony_ci ``` 45e41f4b71Sopenharmony_ci **Usage Example** 46e41f4b71Sopenharmony_ci  47e41f4b71Sopenharmony_ci 48e41f4b71Sopenharmony_ci* To wait for the system parameter with the given name to match the specified value, run the following command: 49e41f4b71Sopenharmony_ci 50e41f4b71Sopenharmony_ci ```bash 51e41f4b71Sopenharmony_ci param wait name [value] [timeout] 52e41f4b71Sopenharmony_ci ``` 53e41f4b71Sopenharmony_ci **Usage Example** 54e41f4b71Sopenharmony_ci  55e41f4b71Sopenharmony_ci 56e41f4b71Sopenharmony_ci* To persistently save the parameters to the workspace, run the following command: 57e41f4b71Sopenharmony_ci 58e41f4b71Sopenharmony_ci ```bash 59e41f4b71Sopenharmony_ci param save 60e41f4b71Sopenharmony_ci ``` 61e41f4b71Sopenharmony_ci **Usage Example** 62e41f4b71Sopenharmony_ci  63
