sys_resource.h man page

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.

sys/resource.h ā€” definitions for XSI resource operations

Synopsis

#include <sys/resource.h>

Description

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 <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 constants, 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 constants 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 constants 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 symbols 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(), getrlimit(), getrusage()

Referenced By

getpriority(3p), getrlimit(3p), getrusage(3p).

2013 IEEE/The Open Group POSIX Programmer's Manual