NOTE: click here if you get an empty page.

GETRUSAGE(2)		   Linux Programmer's Manual		  GETRUSAGE(2)

NAME
       getrusage - get resource usage

SYNOPSIS
       #include <sys/time.h>
       #include <sys/resource.h>

       int getrusage(int who, struct rusage *usage);

DESCRIPTION
       getrusage()  returns  resource usage measures for who, which can be one
       of the following:

       RUSAGE_SELF
	      Return resource usage statistics for the calling process,	 which
	      is the sum of resources used by all threads in the process.

       RUSAGE_CHILDREN
	      Return resource usage statistics for all children of the calling
	      process that have terminated and been waited for.	 These statis-
	      tics  will include the resources used by grandchildren, and fur-
	      ther removed descendants, if all of the intervening  descendants
	      waited on their terminated children.

       RUSAGE_THREAD (since Linux 2.6.26)
	      Return resource usage statistics for the calling thread.

       The  resource usages are returned in the structure pointed to by usage,
       which has the following form:

	    struct rusage {
		struct timeval ru_utime; /* user time used */
		struct timeval ru_stime; /* system time used */
		long   ru_maxrss;	 /* maximum resident set size */
		long   ru_ixrss;	 /* integral shared memory size */
		long   ru_idrss;	 /* integral unshared data size */
		long   ru_isrss;	 /* integral unshared stack size */
		long   ru_minflt;	 /* page reclaims */
		long   ru_majflt;	 /* page faults */
		long   ru_nswap;	 /* swaps */
		long   ru_inblock;	 /* block input operations */
		long   ru_oublock;	 /* block output operations */
		long   ru_msgsnd;	 /* messages sent */
		long   ru_msgrcv;	 /* messages received */
		long   ru_nsignals;	 /* signals received */
		long   ru_nvcsw;	 /* voluntary context switches */
		long   ru_nivcsw;	 /* involuntary context switches */
	    };

RETURN VALUE
       On success, zero is returned.  On error, -1 is returned, and  errno  is
       set appropriately.

ERRORS
       EFAULT usage points outside the accessible address space.

       EINVAL who is invalid.

CONFORMING TO
       SVr4,  4.3BSD.	POSIX.1-2001 specifies getrusage(), but only specifies
       the fields ru_utime and ru_stime.

NOTES
       Including <sys/time.h> is not required these days, but increases porta-
       bility.	(Indeed, struct timeval is defined in <sys/time.h>.)

       In Linux kernel versions before 2.6.9, if the disposition of SIGCHLD is
       set to SIG_IGN then the resource usages of child processes are automat-
       ically  included	 in  the  value	 returned by RUSAGE_CHILDREN, although
       POSIX.1-2001 explicitly prohibits this.	This non-conformance is recti-
       fied in Linux 2.6.9 and later.

       The  above struct was taken from 4.3BSD Reno.  Not all fields are mean-
       ingful under Linux.  In linux 2.4 only the fields  ru_utime,  ru_stime,
       ru_minflt, and ru_majflt are maintained.	 Since Linux 2.6, ru_nvcsw and
       ru_nivcsw are also maintained.

SEE ALSO
       getrlimit(2), times(2), wait(2), wait4(2)

Linux 2.6.9			  2004-11-16			  GETRUSAGE(2)