illumos: manual page: kstat

KSTAT_LOOKUP(3KSTAT) Kernel Statistics Library Functions KSTAT_LOOKUP(3KSTAT)

NAME

kstat_lookup, kstat_data_lookup - find a kstat by name

LIBRARY

Kernel Statistics Library (libkstat, -lkstat)

SYNOPSIS

#include <kstat.h>

kstat_t *
kstat_lookup(kstat_ctl_t *kc, const char *ks_module, int ks_instance,
const char *ks_name);

void *
kstat_data_lookup(kstat_t *ksp, const char *name);

DESCRIPTION

The kstat_lookup() function traverses the kstat chain, `kc->kc_chain',
searching for a kstat with the same ks_module, ks_instance, and ks_name
fields; this triplet uniquely identifies a kstat. If ks_module, is NULL,
ks_instance is -1, or ks_name is NULL, those fields will be ignored in the
search. For example, kstat_lookup(kc, NULL, -1, foo) will find the first
kstat with name "foo".

The kstat_data_lookup() function searches the kstat's data section for the
record with the specified name. This operation is valid only for those
kstat types that have named data records: KSTAT_TYPE_NAMED and
KSTAT_TYPE_TIMER.

Lifetime

The kstat_t structures and any associated data are owned by the library and
the corresponding handle, kc. That is, two callers with same library
handle will generally have the same memory returned to them, though this is
not a guaranteed part of the interface. Callers should not modify or
attempt to free the data associated with either. Calling the
kstat_chain_update(3KSTAT) or kstat_close(3KSTAT) functions on the handle
kc will cause the pointers returned from these functions with the same
handle to be invalid.

RETURN VALUES

The kstat_lookup() function returns a pointer to the requested kstat if it
is found. Otherwise it returns NULL and sets errno to indicate the error.

The kstat_data_lookup() function returns a pointer to the requested data
record if it is found. Otherwise it returns NULL and sets errno to
indicate the error.

FILES

/dev/kstat kernel statistics driver character device

ERRORS

The kstat_lookup() and kstat_data_lookup() functions will fail if:

EINVAL An attempt was made to look up data for a kstat that was
not of type KSTAT_TYPE_NAMED or KSTAT_TYPE_TIMER.

ENOENT The requested kstat could not be found.

INTERFACE STABILITY

Committed

MT-LEVEL
Unsafe