KVM_NEXTPROC(3KVM) Kernel VM Library Functions KVM_NEXTPROC(3KVM)
NAME
kvm_nextproc, kvm_getproc, kvm_setproc - read system process
structures
SYNOPSIS
cc [
flag... ]
file...
-lkvm [
library...]
#include <kvm.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/proc.h>
struct proc *kvm_nextproc(
kvm_t *kd);
int kvm_setproc(
kvm_t *kd);
struct proc *kvm_getproc(
kvm_t *kd,
pid_t pid);
DESCRIPTION
The
kvm_nextproc() function reads sequentially all of the system
process structures from the kernel identified by
kd (see
kvm_open(3KVM)). Each call to
kvm_nextproc() returns a pointer to
the static memory area that contains a copy of the next valid process
table entry. There is no guarantee that the data will remain valid
across calls to
kvm_nextproc(),
kvm_setproc(), or
kvm_getproc(). If
the process structure must be saved, it should be copied to non-
volatile storage.
For performance reasons, many implementations will cache a set of
system process structures. Since the system state is liable to change
between calls to
kvm_nextproc(), and since the cache may contain
obsolete information, there is no guarantee that every process
structure returned refers to an active process, nor is it certain
that all processes will be reported.
The
kvm_setproc() function rewinds the process list, enabling
kvm_nextproc() to rescan from the beginning of the system process
table. This function will always flush the process structure cache,
allowing an application to re-scan the process table of a running
system.
The
kvm_getproc() function locates the
proc structure of the process
specified by
pid and returns a pointer to it. Although this function
does not interact with the process table pointer manipulated by
kvm_nextproc(), the restrictions regarding the validity of the data
still apply.
RETURN VALUES
On success,
kvm_nextproc() returns a pointer to a copy of the next
valid process table entry. On failure, it returns
NULL.
On success,
kvm_getproc() returns a pointer to the
proc structure of
the process specified by
pid. On failure, it returns
NULL.
The
kvm_setproc() function returns 0 on success and -1 on failure.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Stable |
+--------------------+-----------------+
|MT-Level | Unsafe |
+--------------------+-----------------+
SEE ALSO
kvm_getu(3KVM),
kvm_kread(3KVM),
kvm_open(3KVM),
attributes(7) May 2, 2002 KVM_NEXTPROC(3KVM)
