If newoffset is negative, the system nice value is set to 20 minus the absolute value of newoffset . If the UNIX95 environment variable is set and the newoffset is negative, the system nice value is set to current nice value minus the absolute value of newoffset . Only users with appropriate privileges can reduce the system nice value or set it to less than 20. If this option is omitted, newoffset defaults to 10. This is the default.
All processes owned by each specified user have their system nice values altered.
Only users with appropriate privileges can use this option for user names and IDs other than their own. Otherwise, an error message is displayed to indicate the reason for failure. However, if the UNIX95 envionment variable is set, no reporting is done unless the command fails.