Unix in a Nutshell, 4th Edition

Name

nice

Synopsis

    nice [±n]command

Change the execution priority for command or, if none is given, change priority for the current shell. (See also nice in Chapter 2.) The priority range is -20 to 19, with a default of 4. The range is backwards from what you might expect: -20 gives the highest priority (fastest execution); 19 gives the lowest. Only a privileged user may specify a negative number.

+ n

Add n to the priority value (lower job priority).

- n

Subtract n from the priority value (raise job priority). Privileged users only.