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Expressions régulières,
Syntaxe et mise en oeuvre :

ISBN : 978-2-7460-9712-4
EAN : 9782746097124
(Editions ENI)

GNU/Linux

CentOS 5.6

getrusage(2)


GETRUSAGE

GETRUSAGE

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
CONFORMING TO
NOTES
SEE ALSO

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 statistics will include the resources used by grandchildren, and further 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 portability. (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 automatically included in the value returned by RUSAGE_CHILDREN, although POSIX.1-2001 explicitly prohibits this. This non-conformance is rectified in Linux 2.6.9 and later.

The above struct was taken from 4.3BSD Reno. Not all fields are meaningful 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)



getrusage(2)