NAME

nice − change priority of a process

SYNOPSIS

int nice (incr)
int incr;

DESCRIPTION

Nice adds the value of incr to the nice value of the calling process.  A process’s nice value is a positive number for which a more positive value results in lower CPU priority. 

A maximum nice value of 39 and a minimum nice value of 0 are imposed by the system.  Requests for values above or below these limits result in the nice value being set to the corresponding limit. 

RETURN VALUE

Upon successful completion, nice returns the new nice value minus 20.  Otherwise, a value of −1 is returned and errno is set to indicate the error. 

Note that nice assumes a user process priority value of 20.  If the super-user of your system has changed the user process priority value to something less than 20, certain increments can cause nice to return −1, which is indistinguishable from an error return. 

ERRORS

­[EPERM] Nice will fail and not change the nice value if incr is negative or greater than 40 and the effective user ID of the calling process is not super-user. 

HARDWARE DEPENDENCIES

Integral PC
Normal users have all super-user capabilities.

SEE ALSO

nice(1), exec(2). 

Hewlett-Packard Company  —  Version B.1,  May 11, 2021