Get or set the priority of a process — ps_windows_nice

ps_get_nice() returns the current priority, ps_set_nice() sets a new priority, ps_windows_nice_values() list the possible priority values on Windows.

Usage

ps_windows_nice_values()

ps_get_nice(p = ps_handle())

ps_set_nice(p = ps_handle(), value)

Arguments

p: Process handle.
value: On Windows it must be a string, one of the values of ps_windows_nice_values(). On Unix it is a priority value that is smaller than or equal to 20.

Value

ps_windows_nice_values() return a character vector of possible priority values on Windows.

ps_get_nice() returns a string from ps_windows_nice_values() on Windows. On Unix it returns an integer smaller than or equal to 20.

ps_set_nice() return NULL invisibly.

Details

Priority values are different on Windows and Unix.

On Unix, priority is an integer, which is maximum 20. 20 is the lowest priority.

Rules:

On Windows you can only set the priority of the processes the current user has PROCESS_SET_INFORMATION access rights to. This typically means your own processes.
On Unix you can only set the priority of the your own processes. The superuser can set the priority of any process.
On Unix you cannot set a higher priority, unless you are the superuser. (I.e. you cannot set a lower number.)
On Unix the default priority of a process is zero.