hwclock

hwclock

The hwclock command in Linux is used to access and modify the hardware clock. The hardware clock is a battery-backed clock that keeps track of the system time even when the machine is powered off.

The hwclock command takes the following arguments:

• options: Optional arguments that control the behavior of hwclock.

The following are some of the most common options for the hwclock command:

• -r: Reads the hardware clock.

• -w: Writes the hardware clock.

• -s: Sets the hardware clock to the system time.

• -d: Displays the drift between the hardware clock and the system time.

• -f: Specifies the file to read or write the hardware clock from or to.

For example, the following command will read the hardware clock:

hwclock -r

The hwclock command is a useful tool for setting and adjusting the hardware clock. It is a valuable tool for anyone who needs to keep their system time accurate.

Here are some additional things to keep in mind about hwclock:

• The hwclock command must be run as root or by a user who has permission to modify the hardware clock.

• The hwclock command can be used to set the hardware clock to UTC or to local time.

• The hwclock command can be used to adjust the hardware clock for drift.

Here are some examples of how to use hwclock:

• To read the hardware clock:

hwclock -r

• To write the hardware clock:

hwclock -w

• To set the hardware clock to UTC:

hwclock -s -f /etc/adjtime

• To set the hardware clock to local time:

hwclock -s -f /etc/localtime

• To adjust the hardware clock for drift:

hwclock -s -f /etc/adjtime -d

The hwclock command is a powerful and versatile tool that can be used to access and modify the hardware clock. It is a valuable tool for anyone who needs to keep their system time accurate.

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