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(3) and setpriority(3) :
- 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.