1.\" $NetBSD: kvm_getprocs.3,v 1.6 2000/04/15 04:38:47 simonb Exp $ 2.\" 3.\" Copyright (c) 1992, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" This code is derived from software developed by the Computer Systems 7.\" Engineering group at Lawrence Berkeley Laboratory under DARPA contract 8.\" BG 91-66 and contributed to Berkeley. 9.\" 10.\" Redistribution and use in source and binary forms, with or without 11.\" modification, are permitted provided that the following conditions 12.\" are met: 13.\" 1. Redistributions of source code must retain the above copyright 14.\" notice, this list of conditions and the following disclaimer. 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in the 17.\" documentation and/or other materials provided with the distribution. 18.\" 3. All advertising materials mentioning features or use of this software 19.\" must display the following acknowledgement: 20.\" This product includes software developed by the University of 21.\" California, Berkeley and its contributors. 22.\" 4. Neither the name of the University nor the names of its contributors 23.\" may be used to endorse or promote products derived from this software 24.\" without specific prior written permission. 25.\" 26.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36.\" SUCH DAMAGE. 37.\" 38.\" @(#)kvm_getprocs.3 8.1 (Berkeley) 6/4/93 39.\" 40.Dd June 4, 1993 41.Dt KVM_GETPROCS 3 42.Os 43.Sh NAME 44.Nm kvm_getprocs , 45.Nm kvm_getargv , 46.Nm kvm_getenvv 47.Nd access user process state 48.Sh LIBRARY 49.Lb libkvm 50.Sh SYNOPSIS 51.Fd #include <kvm.h> 52.Fd #include <sys/sysctl.h> 53.\" .Fa kvm_t *kd 54.br 55.Ft struct kinfo_proc * 56.Fn kvm_getprocs "kvm_t *kd" "int op" "int arg" "int *cnt" 57.Ft char ** 58.Fn kvm_getargv "kvm_t *kd" "const struct kinfo_proc *p" "int nchr" 59.Ft char ** 60.Fn kvm_getenvv "kvm_t *kd" "const struct kinfo_proc *p" "int nchr" 61.Sh DESCRIPTION 62.Fn kvm_getprocs 63returns a (sub-)set of active processes in the kernel indicated by 64.Fa kd. 65The 66.Fa op 67and 68.Fa arg 69arguments constitute a predicate which limits the set of processes 70returned. The value of 71.Fa op 72describes the filtering predicate as follows: 73.Pp 74.Bl -tag -width 20n -offset indent -compact 75.It Sy KERN_PROC_ALL 76all processes 77.It Sy KERN_PROC_PID 78processes with process id 79.Fa arg 80.It Sy KERN_PROC_PGRP 81processes with process group 82.Fa arg 83.It Sy KERN_PROC_SESSION 84processes with session 85.Fa arg 86.It Sy KERN_PROC_TTY 87processes with tty 88.Fa arg 89.It Sy KERN_PROC_UID 90processes with effective user id 91.Fa arg 92.It Sy KERN_PROC_RUID 93processes with real user id 94.Fa arg 95.El 96.Pp 97The number of processes found is returned in the reference parameter 98.Fa cnt . 99The processes are returned as a contiguous array of kinfo_proc structures. 100This memory is locally allocated, and subsequent calls to 101.Fn kvm_getprocs 102and 103.Fn kvm_close 104will overwrite this storage. 105.Pp 106If the 107.Fa op 108argument for 109.Fn kvm_getprocs 110is 111.Sy KERN_PROC_TTY , 112.Fa arg 113can also be 114.Sy KERN_PROC_TTY_NODEV 115to select processes with no controlling tty and 116.Sy KERN_PROC_TTY_REVOKE 117to select processes which have had their controlling tty 118revoked. 119.Pp 120.Fn kvm_getargv 121returns a null-terminated argument vector that corresponds to the 122command line arguments passed to process indicated by 123.Fa p . 124Most likely, these arguments correspond to the values passed to 125.Xr exec 3 126on process creation. This information is, however, 127deliberately under control of the process itself. 128Note that the original command name can be found, unaltered, 129in the p_comm field of the process structure returned by 130.Fn kvm_getprocs . 131.Pp 132The 133.Fa nchr 134argument indicates the maximum number of characters, including null bytes, 135to use in building the strings. If this amount is exceeded, the string 136causing the overflow is truncated and the partial result is returned. 137This is handy for programs like 138.Xr ps 1 139and 140.Xr w 1 141that print only a one line summary of a command and should not copy 142out large amounts of text only to ignore it. 143If 144.Fa nchr 145is zero, no limit is imposed and all argument strings are returned in 146their entirety. 147.Pp 148The memory allocated to the argv pointers and string storage 149is owned by the kvm library. Subsequent 150.Fn kvm_getprocs 151and 152.Xr kvm_close 3 153calls will clobber this storage. 154.Pp 155The 156.Fn kvm_getenvv 157function is similar to 158.Fn kvm_getargv 159but returns the vector of environment strings. This data is 160also alterable by the process. 161.Sh RETURN VALUES 162.Fn kvm_getprocs , 163.Fn kvm_getargv , 164and 165.Fn kvm_getenvv , 166all return 167.Dv NULL 168on failure. 169.Pp 170.Sh BUGS 171These routines do not belong in the kvm interface. 172.Sh SEE ALSO 173.Xr kvm 3 , 174.Xr kvm_close 3 , 175.Xr kvm_geterr 3 , 176.Xr kvm_nlist 3 , 177.Xr kvm_open 3 , 178.Xr kvm_openfiles 3 , 179.Xr kvm_read 3 , 180.Xr kvm_write 3 181