sys/resource.h — definitions for resource operations
#include <sys/resource.h>
[XSI] 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.
[XSI] 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.[XSI] 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 image.
- RLIMIT_CPU
- [XSI] 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.
[XSI] int getpriority(int, id_t); int getrlimit(int, struct rlimit *); [XSI] int getrusage(int, struct rusage *); int setpriority(int, id_t, int); int setrlimit(int, const struct rlimit *);[XSI] 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>.
None.
None.
None.
XSH getpriority , getrlimit , getrusage
First released in Issue 4, Version 2.
Large File System extensions are added.
This reference page is clarified with respect to macros and symbolic constants.
Austin Group Defects 51 and 1669 are applied, moving the getrlimit() and setrlimit() functions, excluding the RLIMIT_CPU limit, from the XSI option to the Base.
Austin Group Defect 1141 is applied, changing the description of RLIMIT_CORE.
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