hdparm:tldr:79640

This command is using the hdparm tool to manage the power-saving feature known as standby or sleep mode for a specific device. Here's the breakdown of the command:

• sudo: It's a command that allows the user to execute another command (in this case, hdparm) with administrative privileges. It is often used when executing commands that require root or superuser access.

• hdparm: It is a command-line utility in Linux/Unix systems used to interact with ATA (Advanced Technology Attachment) devices, such as hard drives or solid-state drives (SSDs).

• -S ${standby_timeout}: -S is an option in hdparm used to set the standby or sleep timeout value for the specified device. ${standby_timeout} is a placeholder for a specific value you need to provide. The standby timeout value represents the idle time after which the device will automatically go into a low-power mode.

• ${device}: It is another placeholder referring to the device for which you want to set the standby timeout. You need to replace ${device} with the device name or path, like /dev/sda for a hard drive.

Combining all these elements, the command executes hdparm with administrative privileges to set the standby timeout value for a particular device by specifying the timeout value with -S option, and providing the device name or path with ${device} placeholder.