1.\" Copyright (c) 1992, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" This code is derived from software developed by the Computer Systems 5.\" Engineering group at Lawrence Berkeley Laboratory under DARPA contract 6.\" BG 91-66 and contributed to Berkeley. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)kvm_getprocs.3 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD$ 34.\" 35.Dd November 22, 2011 36.Dt KVM_GETPROCS 3 37.Os 38.Sh NAME 39.Nm kvm_getprocs , 40.Nm kvm_getargv , 41.Nm kvm_getenvv 42.Nd access user process state 43.Sh LIBRARY 44.Lb libkvm 45.Sh SYNOPSIS 46.In kvm.h 47.In sys/param.h 48.In sys/sysctl.h 49.In sys/user.h 50.\" .Fa kvm_t *kd 51.Ft struct kinfo_proc * 52.Fn kvm_getprocs "kvm_t *kd" "int op" "int arg" "int *cnt" 53.Ft char ** 54.Fn kvm_getargv "kvm_t *kd" "const struct kinfo_proc *p" "int nchr" 55.Ft char ** 56.Fn kvm_getenvv "kvm_t *kd" "const struct kinfo_proc *p" "int nchr" 57.Sh DESCRIPTION 58The 59.Fn kvm_getprocs 60function returns a (sub-)set of active processes in the kernel indicated by 61.Fa kd . 62The 63.Fa op 64and 65.Fa arg 66arguments constitute a predicate which limits the set of processes 67returned. 68The value of 69.Fa op 70describes the filtering predicate as follows: 71.Pp 72.Bl -tag -width 20n -offset indent -compact 73.It Dv KERN_PROC_ALL 74all processes and kernel visible threads 75.It Dv KERN_PROC_PROC 76all processes, without threads 77.It Dv KERN_PROC_PID 78processes with process ID 79.Fa arg 80.It Dv KERN_PROC_PGRP 81processes with process group 82.Fa arg 83.It Dv KERN_PROC_SESSION 84processes with session 85.Fa arg 86.It Dv KERN_PROC_TTY 87processes with TTY 88.Fa arg 89.It Dv KERN_PROC_UID 90processes with effective user ID 91.Fa arg 92.It Dv KERN_PROC_RUID 93processes with real user ID 94.Fa arg 95.It Dv KERN_PROC_INC_THREAD 96modifier to return all kernel visible threads when filtering 97by process ID, process group, TTY, user ID, and real user ID 98.El 99.Pp 100The number of processes found is returned in the reference parameter 101.Fa cnt . 102The processes are returned as a contiguous array of kinfo_proc structures. 103This memory is locally allocated, and subsequent calls to 104.Fn kvm_getprocs 105and 106.Fn kvm_close 107will overwrite this storage. 108.Pp 109The 110.Fn kvm_getargv 111function returns a null-terminated argument vector that corresponds to the 112command line arguments passed to process indicated by 113.Fa p . 114Most likely, these arguments correspond to the values passed to 115.Xr exec 3 116on process creation. 117This information is, however, 118deliberately under control of the process itself. 119Note that the original command name can be found, unaltered, 120in the p_comm field of the process structure returned by 121.Fn kvm_getprocs . 122.Pp 123The 124.Fa nchr 125argument indicates the maximum number of characters, including null bytes, 126to use in building the strings. 127If this amount is exceeded, the string 128causing the overflow is truncated and the partial result is returned. 129This is handy for programs like 130.Xr ps 1 131and 132.Xr w 1 133that print only a one line summary of a command and should not copy 134out large amounts of text only to ignore it. 135If 136.Fa nchr 137is zero, no limit is imposed and all argument strings are returned in 138their entirety. 139.Pp 140The memory allocated to the argv pointers and string storage 141is owned by the kvm library. 142Subsequent 143.Fn kvm_getprocs 144and 145.Xr kvm_close 3 146calls will clobber this storage. 147.Pp 148The 149.Fn kvm_getenvv 150function is similar to 151.Fn kvm_getargv 152but returns the vector of environment strings. 153This data is 154also alterable by the process. 155.Sh RETURN VALUES 156The 157.Fn kvm_getprocs , 158.Fn kvm_getargv , 159and 160.Fn kvm_getenvv 161functions return 162.Dv NULL 163on failure. 164.Sh SEE ALSO 165.Xr kvm 3 , 166.Xr kvm_close 3 , 167.Xr kvm_geterr 3 , 168.Xr kvm_nlist 3 , 169.Xr kvm_open 3 , 170.Xr kvm_openfiles 3 , 171.Xr kvm_read 3 , 172.Xr kvm_write 3 173.Sh BUGS 174These routines do not belong in the kvm interface. 175