KVM_GETPROCS(3) BSD Programmer's Manual KVM_GETPROCS(3)
kvm_getprocs, kvm_getargv, kvm_getenvv, kvm_getproc2, kvm_getargv2,
kvm_getenvv2 - access user process state
#include <sys/param.h>
#include <sys/sysctl.h>
#include <kvm.h>
struct kinfo_proc *
kvm_getprocs(kvm_t *kd, int op, int arg, int *cnt);
char **
kvm_getargv(kvm_t *kd, const struct kinfo_proc *p, int nchr);
char **
kvm_getenvv(kvm_t *kd, const struct kinfo_proc *p, int nchr);
struct kinfo_proc2 *
kvm_getproc2(kvm_t *kd, int op, int arg, size_t elemsize, int *cnt);
char **
kvm_getargv2(kvm_t *kd, const struct kinfo_proc2 *p, int nchr);
char **
kvm_getenvv2(kvm_t *kd, const struct kinfo_proc2 *p, int nchr);
kvm_getprocs() returns a (sub-)set of active processes in the kernel in-
dicated by kd. The op and arg arguments constitute a predicate which lim-
its the set of processes returned. The value of op describes the filter-
ing predicate as follows:
KERN_PROC_KTHREAD
all processes (user-level plus kernel threads)
KERN_PROC_ALL
all user-level processes
KERN_PROC_PID
processes with process ID arg
KERN_PROC_PGRP
processes with process group arg
KERN_PROC_SESSION
processes with session arg
KERN_PROC_TTY
processes with tty(4) arg
KERN_PROC_UID
processes with effective user ID arg
KERN_PROC_RUID
processes with real user ID arg
The number of processes found is returned in the reference parameter cnt.
The processes are returned as a contiguous array of kinfo_proc struc-
tures, the definition for which is available in <sys/sysctl.h>. This
memory is locally allocated, and subsequent calls to kvm_getprocs() and
kvm_close() will overwrite this storage.
kvm_getargv() returns a null-terminated argument vector that corresponds
to the command line arguments passed to process indicated by p. Most
likely, these arguments correspond to the values passed to exec(3) on
process creation. This information is, however, deliberately under con-
trol of the process itself. Note that the original command name can be
found, unaltered, in the p_comm field of the process structure returned
by kvm_getprocs().
The nchr argument indicates the maximum number of characters, including
null bytes, to use in building the strings. If this amount is exceeded,
the string causing the overflow is truncated and the partial result is
returned. This is handy for programs like ps(1) and w(1) that print only
a one line summary of a command and should not copy out large amounts of
text only to ignore it. If nchr is zero, no limit is imposed and all ar-
gument strings are returned in their entirety.
The memory allocated to the argv pointers and string storage is owned by
the kvm(3) library. Subsequent kvm_getprocs() and kvm_close(3) calls will
clobber this storage.
The kvm_getenvv() function is similar to kvm_getargv() but returns the
vector of environment strings. This data is also alterable by the pro-
cess.
kvm_getproc2() is similar to kvm_getprocs() but returns an array of
kinfo_proc2 structures. Additionally, only the first elemsize bytes of
each array entry are returned. If the size of the kinfo_proc2 structure
increases in size in a future release of OpenBSD, the kernel will only
return the requested amount of data for each array entry and programs
that use kvm_getproc2() will continue to function without the need for
recompilation.
The kvm_getargv2() and kvm_getenvv2() functions are equivalents to the
kvm_getargv() and kvm_getenvv() functions that use a kinfo_proc2 struc-
ture to specify the process.
kvm_getprocs(), kvm_getargv(), kvm_getenvv(), kvm_getproc2(),
kvm_getargv2(), and kvm_getenvv2() all return NULL on failure.
kvm(3), kvm_close(3), kvm_geterr(3), kvm_nlist(3), kvm_open(3),
kvm_openfiles(3), kvm_read(3), kvm_write(3)
These routines do not belong in the kvm(3) interface.
MirBSD #10-current June 4, 1993 1