xref: /illumos-gate/usr/src/man/man3kstat/kstat_lookup.3kstat (revision edd580643f2cf1434e252cd7779e83182ea84945)
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KSTAT_LOOKUP 3KSTAT "March 24, 2020"
NAME
kstat_lookup, kstat_data_lookup - find a kstat by name
SYNOPSIS
cc [ flag.\|.\|. ] file.\|.\|. -lkstat [ library.\|.\|.]
#include <kstat.h>

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

void *kstat_data_lookup(kstat_t *ksp, 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 .

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.

FILES
/dev/kstat

kernel statistics driver

ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability Stable
MT-Level Unsafe
SEE ALSO
kstat(3KSTAT), kstat_chain_update(3KSTAT), kstat_open(3KSTAT), kstat_read(3KSTAT), attributes(5)