NAME

       sys/resource.h - definitions for XSI resource operations

SYNOPSIS

       #include <sys/resource.h>

DESCRIPTION

       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 following type shall be defined through typedef:

       rlim_t Unsigned integer type used for limit values.

       The following symbolic constants shall be 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 shall be 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 shall define 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 shall define 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 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():

       RLIMIT_CORE
              Limit on size of core 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  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
       <sys/time.h>.

       The following sections are informative.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       <sys/time.h>  ,  <sys/types.h>  ,  the  System  Interfaces volume of IEEE Std 1003.1-2001,
       getpriority(), getrusage(), getrlimit()

COPYRIGHT

       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
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .