nice(3) 						     Library Functions Manual							   nice(3)

NAME

       nice - Changes the scheduling priority of a process

LIBRARY

       Standard C Library (libc) Berkeley Compatibility Library (libbsd)

SYNOPSIS

       #include <unistd.h>

       int nice(      int increment);

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       nice(): XSH4.2

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS

       Specifies a value that is added to the current process priority.  You can specify a negative value.

DESCRIPTION

       The nice() function adds the value specified in the increment parameter to the nice value of the calling process.  The nice value is a non-
       negative number;  a higher nice value gives the process a lower CPU priority.

       When you are using the Standard C Library version of the nice() function, the maximum nice value for a process is 39 (2 * {NZERO} -1)   and
       the minimum is 0 (zero). Requests for values outside these limits result in the nice value being set to the corresponding limit.

       [XPG4-UNIX]  If execution of the Standard C Library nice() function fails, the system does not alter the specified priority.

       Any  process  can  lower  its  priority (numerically raise its nice value).  A process must have superuser privileges to raise its priority
       (numerically lower its nice value).

       [Tru64 UNIX]  For backward compatibility, a version of the nice() function is supported that allows nice values in the range of -20 to  20.
       Requests for values above or below these limits result in the nice value being set to the corresponding limit.  To use the backward-compat-
       ible version of nice(), compile with the Berkeley Compatibility Library (libbsd.a).

RETURN VALUES

       Upon successful completion, the nice() function returns the new nice value minus 20 ({NZERO}).  Otherwise, the function returns -1 and sets
       errno to indicate the error.

ERRORS

       The Standard C Library version of nice() sets errno to the specified values for the following conditions: The calling process does not have
       appropriate privilege.

       [Tru64 UNIX]  The libbsd.a version of nice() sets errno to the same values as the setpriority() function. For  information  about  possible
       return values for the setpriority() function, see setpriority(2).

RELATED INFORMATION

       Functions: exec(2), getpriority(2), setpriority(2)

       Standards: standards(5) delim off

																	   nice(3)