<sys/resource.h>(P) POSIX Programmer's Manual <sys/resource.h>(P)
sys/resource.h - definitions for XSI resource operations
The <sys/resource.h> header shall define the following symbolic constants as possible val-
ues 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 following type shall be defined through typedef:
rlim_t Unsigned integer type used for limit values.
The following symbolic constants shall be defined:
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 following symbolic constants shall be defined as possible values of the who parameter
Returns information about the current process.
Returns information about children of the current process.
The <sys/resource.h> header shall define the rlimit structure that includes at least the
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 that includes at least the
struct timeval ru_utime User time used.
struct timeval ru_stime System time used.
The timeval structure shall be defined as described in <sys/time.h> .
The following symbolic constants shall be defined 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 id_t type shall be defined through typedef as described in <sys/types.h> .
Inclusion of the <sys/resource.h> header may also make visible all symbols from
The following sections are informative.
<sys/time.h> , <sys/types.h> , the System Interfaces volume of IEEE Std 1003.1-2001, get-
priority(), getrusage(), getrlimit()
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by
the Institute of Electrical and Electronics Engineers, Inc and The Open Group. 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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 <sys/resource.h>(P)