NAME

sys/resource.h - definitions for XSI resource operations

 SYNOPSIS

#include <sys/resource.h>

 DESCRIPTION

The <sys/resource.h> header defines the following symbolic constants as possible values of the which argument of getpriority() and setpriority():

PRIO_PROCESS

Identifies who argument as a process ID.

PRIO_PGRP

Identifies who argument as a process group ID.

PRIO_USER

Identifies who argument as a user ID.

The following type is defined through typedef:

rlim_t

Unsigned integral type used for limit values.

The following symbolic constants are 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 are 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 defines 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 defines 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 is defined as described in <sys/time.h>.

The following symbolic constants are defined as possible values for the resource argument of getrlimit() and setrlimit():

RLIMIT_CORE

Limit on size of core dump 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 are declared as functions and may also be defined as macros. Function prototypes must be provided for use with an ISO C compiler.

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 is 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>.

 APPLICATION USAGE

None.

 FUTURE DIRECTIONS

None.

 SEE ALSO

getpriority(), getrusage(), getrlimit().