KSTAT_READ(3KSTAT)KSTAT_READ(3KSTAT)NAME
kstat_read, kstat_write - read or write kstat data
SYNOPSIS
cc [ flag... ] file... -lkstat [ library... ]
#include <kstat.h>
kid_t kstat_read(kstat_ctl_t *kc, kstat_t *ksp, void *buf);
kid_t kstat_write(kstat_ctl_t *kc, kstat_t *ksp, void *buf);
DESCRIPTION
The kstat_read() function gets data from the kernel for the kstat
pointed to by ksp. The ksp->ks_data field is automatically allocated
(or reallocated) to be large enough to hold all of the data. The
ksp->ks_ndata field is set to the number of data fields,
ksp->ks_data_size is set to the total size of the data, and
ksp->ks_snaptime is set to the high-resolution time at which the data
snapshot was taken. If buf is non-null, the data is copied from
ksp->ks_data to buf.
The kstat_write() function writes data from buf, or from ksp->ks_data
if buf is NULL, to the corresponding kstat in the kernel. Only the
superuser can use kstat_write().
RETURN VALUES
Upon successful completion, kstat_read() and kstat_write() return the
current kstat chain ID (KCID). Otherwise, they return −1 and set errno
to indicate the error.
ERRORS
The kstat_read() and kstat_write() functions will fail if:
EACCES
An attempt was made to write to a non-writable kstat.
EAGAIN
The kstat was temporarily unavailable for reading or writ‐
ing.
EINVAL
An attempt was made to write data to a kstat, but the num‐
ber of elements or the data size does not match.
ENOMEM
Insufficient storage space is available.
ENXIO
The given kstat could not be located for reading or writ‐
ing.
EOVERFLOW
The data for the given kstat was too large to be stored in
the structure.
EPERM
An attempt was made to write to a kstat, but
{PRIV_SYS_CONFIG} was not asserted in the effective privi‐
lege set.
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 ALSOkstat(3KSTAT), kstat_chain_update(3KSTAT), kstat_lookup(3KSTAT),
kstat_open(3KSTAT), attributes(5), privileges(5)
Aug 3, 2004 KSTAT_READ(3KSTAT)
