man/man3kstat/kstat_read.3kstat

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 KSTAT_READ 3KSTAT "Aug 3, 2004"
 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 writing.


EINVAL

An attempt was made to write data to a kstat, but the number 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 writing.


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 privilege 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 ALSO

kstat(3KSTAT), kstat_chain_update(3KSTAT),
kstat_lookup(3KSTAT), kstat_open(3KSTAT), attributes(5),
privileges(5)