sys_resource (0p) - Linux Man Pages
sys_resource: definitions for XSI resource operations
PROLOGThis 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 --- definitions for XSI resource operations
DESCRIPTIONThe <sys/resource.h> header shall define the following symbolic constants as possible values of the which argument of getpriority() and setpriority():
- Identifies the who argument as a process ID.
- Identifies the who argument as a process group ID.
- Identifies the who argument as a user ID.
The <sys/resource.h> header shall define the following type through typedef:
- 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:
- A value of rlim_t indicating no limit.
- A value of type rlim_t indicating an unrepresentable saved hard limit.
- 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():
- Returns information about the current process.
- 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():
- Limit on size of core file.
- Limit on CPU time per process.
- Limit on data segment size.
- Limit on file size.
- Limit on number of open files.
- Limit on stack size.
- 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>.
COPYRIGHTPortions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) 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.unix.org/online.html .
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