nice(2) [linux man page]
NICE(2) Linux Programmer's Manual NICE(2) NAME
nice - change process priority SYNOPSIS
#include <unistd.h> int nice(int inc); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): nice(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE DESCRIPTION
nice() adds inc to the nice value for the calling process. (A higher nice value means a low priority.) Only the superuser may specify a negative increment, or priority increase. The range for nice values is described in getpriority(2). RETURN VALUE
On success, the new nice value is returned (but see NOTES below). On error, -1 is returned, and errno is set appropriately. ERRORS
EPERM The calling process attempted to increase its priority by supplying a negative inc but has insufficient privileges. Under Linux the CAP_SYS_NICE capability is required. (But see the discussion of the RLIMIT_NICE resource limit in setrlimit(2).) CONFORMING TO
SVr4, 4.3BSD, POSIX.1-2001. However, the Linux and (g)libc (earlier than glibc 2.2.4) return value is nonstandard, see below. SVr4 docu- ments an additional EINVAL error code. NOTES
SUSv2 and POSIX.1-2001 specify that nice() should return the new nice value. However, the Linux syscall and the nice() library function provided in older versions of (g)libc (earlier than glibc 2.2.4) return 0 on success. The new nice value can be found using getprior- ity(2). Since glibc 2.2.4, nice() is implemented as a library function that calls getpriority(2) to obtain the new nice value to be returned to the caller. With this implementation, a successful call can legitimately return -1. To reliably detect an error, set errno to 0 before the call, and check its value when nice() returns -1. SEE ALSO
nice(1), fork(2), getpriority(2), setpriority(2), capabilities(7), renice(1) COLOPHON
This page is part of release 3.27 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2007-07-26 NICE(2)
Check Out this Related Man Page
NICE(2) Linux Programmer's Manual NICE(2) NAME
nice - change process priority SYNOPSIS
#include <unistd.h> int nice(int inc); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): nice(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE DESCRIPTION
nice() adds inc to the nice value for the calling process. (A higher nice value means a low priority.) Only the superuser may specify a negative increment, or priority increase. The range for nice values is described in getpriority(2). RETURN VALUE
On success, the new nice value is returned (but see NOTES below). On error, -1 is returned, and errno is set appropriately. ERRORS
EPERM The calling process attempted to increase its priority by supplying a negative inc but has insufficient privileges. Under Linux the CAP_SYS_NICE capability is required. (But see the discussion of the RLIMIT_NICE resource limit in setrlimit(2).) CONFORMING TO
SVr4, 4.3BSD, POSIX.1-2001. However, the Linux and (g)libc (earlier than glibc 2.2.4) return value is nonstandard, see below. SVr4 docu- ments an additional EINVAL error code. NOTES
SUSv2 and POSIX.1-2001 specify that nice() should return the new nice value. However, the Linux syscall and the nice() library function provided in older versions of (g)libc (earlier than glibc 2.2.4) return 0 on success. The new nice value can be found using getprior- ity(2). Since glibc 2.2.4, nice() is implemented as a library function that calls getpriority(2) to obtain the new nice value to be returned to the caller. With this implementation, a successful call can legitimately return -1. To reliably detect an error, set errno to 0 before the call, and check its value when nice() returns -1. SEE ALSO
nice(1), renice(1), fork(2), getpriority(2), setpriority(2), capabilities(7) COLOPHON
This page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. Linux 2007-07-26 NICE(2)