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(5) for descriptions of the following attributes:


+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Stable |
+--------------------+-----------------+
|MT-Level | Unsafe |
+--------------------+-----------------+

SEE ALSO


kvm_getu(3KVM), kvm_open(3KVM), kvm_kread(3KVM), attributes(5)


May 2, 2002 KVM_NEXTPROC(3KVM)