Execute a command (with its arguments) with lower priority (i.e., be “nice” to other users). With no arguments, nice prints the default scheduling priority (niceness). If nice is a child process, it prints the parent process’s scheduling priority. Niceness has a range of -20 (highest priority) to 19 (lowest priority).
Print a help message and then exit.
Run command with niceness incremented by adjustment (1-19); default is 10. A privileged user can raise priority by specifying a negative adjustment (e.g., -5).
Print version information and then exit.