sys_resource.h(0P) POSIX Programmer's Manual sys_resource.h(0P)PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the corresponding
Linux manual page for details of Linux behavior), or the interface may
not be implemented on Linux.
NAME
sys/resource.h — definitions for XSI resource operations
SYNOPSIS
#include <sys/resource.h>
DESCRIPTION
The <sys/resource.h> header shall define the following symbolic con‐
stants as possible values of the which argument of getpriority() and
setpriority():
PRIO_PROCESS Identifies the who argument as a process ID.
PRIO_PGRP Identifies the who argument as a process group ID.
PRIO_USER Identifies the who argument as a user ID.
The <sys/resource.h> header shall define the following type through
typedef:
rlim_t Unsigned integer type used for limit values.
The <sys/resource.h> header shall define the following symbolic con‐
stants, which shall have values suitable for use in #if preprocessing
directives:
RLIM_INFINITY A value of rlim_t indicating no limit.
RLIM_SAVED_MAX A value of type rlim_t indicating an unrepresentable
saved hard limit.
RLIM_SAVED_CUR A value of type rlim_t indicating an unrepresentable
saved soft limit.
On implementations where all resource limits are representable in an
object of type rlim_t, RLIM_SAVED_MAX and RLIM_SAVED_CUR need not be
distinct from RLIM_INFINITY.
The <sys/resource.h> header shall define the following symbolic con‐
stants as possible values of the who parameter of getrusage():
RUSAGE_SELF Returns information about the current process.
RUSAGE_CHILDREN Returns information about children of the current
process.
The <sys/resource.h> header shall define the rlimit structure, which
shall include at least the following members:
rlim_t rlim_cur The current (soft) limit.
rlim_t rlim_max The hard limit.
The <sys/resource.h> header shall define the rusage structure, which
shall include at least the following members:
struct timeval ru_utime User time used.
struct timeval ru_stime System time used.
The <sys/resource.h> header shall define the timeval structure as
described in <sys/time.h>.
The <sys/resource.h> header shall define the following symbolic con‐
stants as possible values for the resource argument of getrlimit() and
setrlimit():
RLIMIT_CORE Limit on size of core file.
RLIMIT_CPU Limit on CPU time per process.
RLIMIT_DATA Limit on data segment size.
RLIMIT_FSIZE Limit on file size.
RLIMIT_NOFILE Limit on number of open files.
RLIMIT_STACK Limit on stack size.
RLIMIT_AS Limit on address space size.
The following shall be declared as functions and may also be defined as
macros. Function prototypes shall be provided.
int getpriority(int, id_t);
int getrlimit(int, struct rlimit *);
int getrusage(int, struct rusage *);
int setpriority(int, id_t, int);
int setrlimit(int, const struct rlimit *);
The <sys/resource.h> header shall define the id_t type through typedef,
as described in <sys/types.h>.
Inclusion of the <sys/resource.h> header may also make visible all sym‐
bols from <sys/time.h>.
The following sections are informative.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
<sys_time.h>, <sys_types.h>
The System Interfaces volume of POSIX.1‐2008, getpriority(), getr‐
limit(), getrusage()COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
cal and Electronics Engineers, Inc and The Open Group. (This is
POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the source
files to man page format. To report such errors, see https://www.ker‐
nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 sys_resource.h(0P)
