chrt:tldr:9ed09

The "chrt" command in Linux is used to modify the scheduling policy and priority of a specified process or thread. Here is an explanation of the command you provided:

• "chrt" is the command itself.
• "--pid" is an option that specifies the process ID (PID) of the target process/task/thread.
• "${PID}" is a placeholder that needs to be replaced with the actual process ID you want to target.
• "--${select}" is another option that specifies the scheduling policy to be set for the process.
• "${select}" is another placeholder that needs to be replaced with the desired scheduling policy. For example, it could be "fifo" for First-In-First-Out scheduling, "rr" for Round-Robin scheduling, or "other" for a different scheduling policy.

By combining these elements, the command instructs the operating system to modify the scheduling policy and priority of the specified process or thread identified by the provided process ID. The specific scheduling policy is determined by the value assigned to the "${select}" placeholder.