# dmesg ## Command Function This command is used to display system boot and running information. ## Syntax dmesg dmesg \[_-c/-C/-D/-E/-L/-U_\] dmesg -s \[_size_\] dmesg -l \[_level_\] dmesg \> \[_fileA_\] ## Parameters **Table 1** Parameter description

Parameter	Description	Value Range
-c	Prints content in the buffer and clears the buffer.	N/A
-C	Clears the buffer.	N/A
-D/-E	Disables or enables printing to the console.	N/A
-L/-U	Disables or enables printing via the serial port.	N/A
-s size	Sets the size of the buffer.	N/A
-l level	Sets the buffering level.	0 - 5
> fileA	Writes the content in the buffer to the specified file.	N/A

## Usage - This command depends on **LOSCFG\_SHELL\_DMESG**. Before using this command, select **Enable Shell dmesg** on **menuconfig**. Debug ---\> Enable a Debug Version ---\> Enable Shell ---\> Enable Shell dmesg - If no parameter is specified, all content in the buffer is printed. - The parameters followed by hyphens \(-\) are mutually exclusive. 1. Before writing content to a file, ensure that the file system has been mounted. 2. Disabling the serial port printing will adversely affect shell. You are advised to set up a connection using Telnet before disabling the serial port. ## Example Run **dmesg\> dmesg.log**. ## Output Writing the content in the buffer to the **dmesg.log** file: ``` OHOS # dmesg > dmesg.log Dmesg write log to dmesg.log success ```