sys/resource.h - definitions for XSI resource operations

#include <sys/resource.h>

The <sys/resource.h> header shall define the following symbolic constants 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 following type shall be defined through typedef:

rlim_t

Unsigned integer type used for limit values.

The following symbolic constants shall be defined:

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 following symbolic constants shall be defined 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 that includes 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 that includes at least the following members:

struct timeval ru_utime User time used. struct timeval ru_stime System time used.

The timeval structure shall be defined as described in <sys/time.h> .

The following symbolic constants shall be defined 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 id_t type shall be defined through typedef as described in <sys/types.h> .

Inclusion of the <sys/resource.h> header may also make visible all symbols from <sys/time.h>.

The following sections are informative.

None.

None.

None.

<sys/time.h> , <sys/types.h> , the System Interfaces volume of IEEE Std 1003.1-2001, getpriority(), getrusage(), getrlimit()

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. 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.opengroup.org/unix/online.html .