nice[option]command[arguments]
Execute a command and arguments with lower priority
(i.e., be "nice" to other users).
nRun command with a niceness of n (1-19); default
is 10. Higher n
means lower priority. A privileged user can raise
priority by specifying a negative n (e.g., -5).
nice works differently in the C shell (see Section 5).
+n raises priority, -n lowers it, and 4 is the default.