dmesg 命令

常用示例

说明

dmesg prints and controls the kernel ring buffer, which contains messages from the kernel including hardware detection, driver loading, and system events. It is essential for debugging hardware and driver issues.

参数

-l, --level level

Restrict output to specified log levels (emerg, alert, crit, err, warn, notice, info, debug)

-f, --facility facility

Restrict output to specified facilities (kern, user, mail, daemon, etc.)

-T, --ctime

Print human-readable timestamps

-H, --human

Enable human-readable output with colors and timestamps

-w, --follow

Wait for new messages (like tail -f)

-L, --color

Colorize output

-c, --read-clear

Clear the ring buffer after printing

-C, --clear

Clear the ring buffer without printing

-n, --console-level level

Set level of messages printed to console

-k, --kernel

Print kernel messages only

-u, --userspace

Print userspace messages only

--time-format _format_

Timestamp format: ctime, reltime, delta, iso, raw

--since _time_

Display records since the specified time

--until _time_

Display records until the specified time

-J, --json

Output in JSON format

-t, --notime

Do not print kernel timestamps

-r, --raw

Print raw message buffer with log-level prefixes

-x, --decode

Decode facility and level to human-readable prefixes