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Revision 1.14, Tue Feb 10 12:48:48 2004 UTC (16 years, 7 months ago) by jmmv
List sys/param.h as a prerequisite of sys/sysctl.h. Bump date.
.\" $NetBSD: kvm_getprocs.3,v 1.14 2004/02/10 12:48:48 jmmv Exp $ .\" .\" Copyright (c) 1992, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" This code is derived from software developed by the Computer Systems .\" Engineering group at Lawrence Berkeley Laboratory under DARPA contract .\" BG 91-66 and contributed to Berkeley. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)kvm_getprocs.3 8.1 (Berkeley) 6/4/93 .\" .Dd February 10, 2004 .Dt KVM_GETPROCS 3 .Os .Sh NAME .Nm kvm_getprocs , .Nm kvm_getargv , .Nm kvm_getenvv .Nd access user process state .Sh LIBRARY .Lb libkvm .Sh SYNOPSIS .In kvm.h .In sys/param.h .In sys/sysctl.h .\" .Fa kvm_t *kd .br .Ft struct kinfo_proc * .Fn kvm_getprocs "kvm_t *kd" "int op" "int arg" "int *cnt" .Ft char ** .Fn kvm_getargv "kvm_t *kd" "const struct kinfo_proc *p" "int nchr" .Ft char ** .Fn kvm_getenvv "kvm_t *kd" "const struct kinfo_proc *p" "int nchr" .Ft struct kinfo_proc2 * .Fn kvm_getproc2 "kvm_t *kd" "int op" "int arg" "int elemsize" "int *cnt" .Ft char ** .Fn kvm_getargv2 "kvm_t *kd" "const struct kinfo_proc2 *p" "int nchr" .Ft char ** .Fn kvm_getenvv2 "kvm_t *kd" "const struct kinfo_proc2 *p" "int nchr" .Sh DESCRIPTION .Fn kvm_getprocs returns a (sub-)set of active processes in the kernel indicated by .Fa kd . The .Fa op and .Fa arg arguments constitute a predicate which limits the set of processes returned. The value of .Fa op describes the filtering predicate as follows: .Pp .Bl -tag -width 20n -offset indent -compact .It Sy KERN_PROC_ALL all processes .It Sy KERN_PROC_PID processes with process id .Fa arg .It Sy KERN_PROC_PGRP processes with process group .Fa arg .It Sy KERN_PROC_SESSION processes with session id .Fa arg .It Sy KERN_PROC_TTY processes with tty device .Fa arg .It Sy KERN_PROC_UID processes with effective user id .Fa arg .It Sy KERN_PROC_RUID processes with real user id .Fa arg .It Sy KERN_PROC_GID processes with effective group id .Fa arg .It Sy KERN_PROC_RGID processes with real group id .Fa arg .El .Pp The number of processes found is returned in the reference parameter .Fa cnt . The processes are returned as a contiguous array of .Sy kinfo_proc structures. This memory is locally allocated, and subsequent calls to .Fn kvm_getprocs and .Fn kvm_close will overwrite this storage. .Pp If the .Fa op argument for .Fn kvm_getprocs is .Sy KERN_PROC_TTY , .Fa arg can also be .Sy KERN_PROC_TTY_NODEV to select processes with no controlling tty and .Sy KERN_PROC_TTY_REVOKE to select processes which have had their controlling tty revoked. .Pp .Fn kvm_getargv returns a null-terminated argument vector that corresponds to the command line arguments passed to process indicated by .Fa p . Most likely, these arguments correspond to the values passed to .Xr exec 3 on process creation. This information is, however, deliberately under control 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 .Fn kvm_getprocs . .Pp The .Fa 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 .Xr ps 1 and .Xr 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 .Fa nchr is zero, no limit is imposed and all argument strings are returned in their entirety. .Pp The memory allocated to the argv pointers and string storage is owned by the kvm library. Subsequent .Fn kvm_getprocs and .Xr kvm_close 3 calls will clobber this storage. .Pp The .Fn kvm_getenvv function is similar to .Fn kvm_getargv but returns the vector of environment strings. This data is also alterable by the process. .Pp .Fn kvm_getproc2 is similar to .Fn kvm_getprocs but returns an array of .Sy kinfo_proc2 structures. Additionally, only the first .Fa elemsize bytes of each array entry are returned. If the size of the .Sy kinfo_proc2 structure increases in size in a future release of .Nx the kernel will only return the requested amount of data for each array entry and programs that use .Fn kvm_getproc2 will continue to function without the need for recompilation. .Pp The .Fn kvm_getargv2 and .Fn kvm_getenvv2 are equivalents to the .Fn kvm_getargv and .Fn kvm_getenvv functions but use a .Sy kinfo_proc2 structure to specify the process. .Pp If called against an active kernel, the .Fn kvm_getproc2 , .Fn kvm_getargv2 , and .Fn kvm_getenvv2 functions will use the .Xr sysctl 3 interface and do not require access to the kernel memory device file or swap device. .Sh RETURN VALUES .Fn kvm_getprocs , .Fn kvm_getargv , .Fn kvm_getenvv , .Fn kvm_getproc2 , .Fn kvm_getargv2 , and .Fn kvm_getenvv2 all return .Dv NULL on failure. .Sh SEE ALSO .Xr kvm 3 , .Xr kvm_close 3 , .Xr kvm_geterr 3 , .Xr kvm_nlist 3 , .Xr kvm_open 3 , .Xr kvm_openfiles 3 , .Xr kvm_read 3 , .Xr kvm_write 3 .Sh BUGS These routines do not belong in the kvm interface.