Display the RTC value without changing the system clock.
Which command is appropriate?
hwclock --show reads and displays the hardware real-time clock.
Detailed explanation
hwclock --showCorrect. --show reads the hardware clock.
Correct. --show reads the hardware clock.
hwclock --systohcIncorrect. --systohc writes the system clock to the RTC.
Incorrect. --systohc writes the system clock to the RTC.
hwclock --hctosysIncorrect. --hctosys writes the RTC to the system clock.
Incorrect. --hctosys writes the RTC to the system clock.
date -uIncorrect. date -u formats system-clock output.
Incorrect. date -u formats system-clock output.
Try it yourself
An example you can run in a temporary verification environment.
hwclock --help 2>&1 | grep -E -- '--show| -r' | head -n 1Expected result
--showまたはread hardware clockのhelp行Key points
- Read RTC
- No change
- Separate from system clock
Notes
- Environment: util-linux hwclock helpの読取のみ
- Command output formatting can vary slightly by distribution or tool version.
- Run the example in a temporary directory or process when possible.
Foundation review
Read the scope first
Check whether the command acts on the current shell, a new process, an existing process, or a file.
Verify the observable result
Use the supplied command and compare the output with the expected result.