1.\" $OpenBSD: kvm_getprocs.3,v 1.13 2007/05/31 19:19:35 jmc Exp $ 2.\" $NetBSD: kvm_getprocs.3,v 1.13 2003/08/07 16:44:37 agc Exp $ 3.\" 4.\" Copyright (c) 1992, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" This code is derived from software developed by the Computer Systems 8.\" Engineering group at Lawrence Berkeley Laboratory under DARPA contract 9.\" BG 91-66 and contributed to Berkeley. 10.\" 11.\" Redistribution and use in source and binary forms, with or without 12.\" modification, are permitted provided that the following conditions 13.\" are met: 14.\" 1. Redistributions of source code must retain the above copyright 15.\" notice, this list of conditions and the following disclaimer. 16.\" 2. Redistributions in binary form must reproduce the above copyright 17.\" notice, this list of conditions and the following disclaimer in the 18.\" documentation and/or other materials provided with the distribution. 19.\" 3. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)kvm_getprocs.3 8.1 (Berkeley) 6/4/93 36.\" 37.Dd $Mdocdate: May 31 2007 $ 38.Dt KVM_GETPROCS 3 39.Os 40.Sh NAME 41.Nm kvm_getprocs , 42.Nm kvm_getargv , 43.Nm kvm_getenvv , 44.Nm kvm_getproc2 , 45.Nm kvm_getargv2 , 46.Nm kvm_getenvv2 47.Nd access user process state 48.Sh SYNOPSIS 49.Fd #include <sys/param.h> 50.Fd #include <sys/sysctl.h> 51.Fd #include <kvm.h> 52.Ft struct kinfo_proc * 53.Fn kvm_getprocs "kvm_t *kd" "int op" "int arg" "int *cnt" 54.Ft char ** 55.Fn kvm_getargv "kvm_t *kd" "const struct kinfo_proc *p" "int nchr" 56.Ft char ** 57.Fn kvm_getenvv "kvm_t *kd" "const struct kinfo_proc *p" "int nchr" 58.Ft struct kinfo_proc2 * 59.Fn kvm_getproc2 "kvm_t *kd" "int op" "int arg" "size_t elemsize" "int *cnt" 60.Ft char ** 61.Fn kvm_getargv2 "kvm_t *kd" "const struct kinfo_proc2 *p" "int nchr" 62.Ft char ** 63.Fn kvm_getenvv2 "kvm_t *kd" "const struct kinfo_proc2 *p" "int nchr" 64.Sh DESCRIPTION 65.Fn kvm_getprocs 66returns a (sub-)set of active processes in the kernel indicated by 67.Fa kd . 68The 69.Fa op 70and 71.Fa arg 72arguments constitute a predicate which limits the set of processes returned. 73The value of 74.Fa op 75describes the filtering predicate as follows: 76.Pp 77.Bl -tag -width 20n -offset indent -compact 78.It Dv KERN_PROC_KTHREAD 79all processes (user-level plus kernel threads) 80.It Dv KERN_PROC_ALL 81all user-level processes 82.It Dv KERN_PROC_PID 83processes with process ID 84.Fa arg 85.It Dv KERN_PROC_PGRP 86processes with process group 87.Fa arg 88.It Dv KERN_PROC_SESSION 89processes with session 90.Fa arg 91.It Dv KERN_PROC_TTY 92processes with 93.Xr tty 4 94.Fa arg 95.It Dv KERN_PROC_UID 96processes with effective user ID 97.Fa arg 98.It Dv KERN_PROC_RUID 99processes with real user ID 100.Fa arg 101.El 102.Pp 103The number of processes found is returned in the reference parameter 104.Fa cnt . 105The processes are returned as a contiguous array of 106.Vt kinfo_proc 107structures, the definition for which is available in 108.Aq Pa sys/sysctl.h . 109This memory is locally allocated, and subsequent calls to 110.Fn kvm_getprocs 111and 112.Fn kvm_close 113will overwrite this storage. 114.Pp 115.Fn kvm_getargv 116returns a null-terminated argument vector that corresponds to the 117command line arguments passed to process indicated by 118.Fa p . 119Most likely, these arguments correspond to the values passed to 120.Xr exec 3 121on process creation. 122This information is, however, 123deliberately under control of the process itself. 124Note that the original command name can be found, unaltered, 125in the 126.Va p_comm 127field of the process structure returned by 128.Fn kvm_getprocs . 129.Pp 130The 131.Fa nchr 132argument indicates the maximum number of characters, including null bytes, 133to use in building the strings. 134If this amount is exceeded, the string 135causing the overflow is truncated and the partial result is returned. 136This is handy for programs like 137.Xr ps 1 138and 139.Xr w 1 140that print only a one line summary of a command and should not copy 141out large amounts of text only to ignore it. 142If 143.Fa nchr 144is zero, no limit is imposed and all argument strings are returned in 145their entirety. 146.Pp 147The memory allocated to the 148.Li argv 149pointers and string storage is owned by the 150.Xr kvm 3 151library. 152Subsequent 153.Fn kvm_getprocs 154and 155.Xr kvm_close 3 156calls will clobber this storage. 157.Pp 158The 159.Fn kvm_getenvv 160function is similar to 161.Fn kvm_getargv 162but returns the vector of environment strings. 163This data is also alterable by the process. 164.Pp 165.Fn kvm_getproc2 166is similar to 167.Fn kvm_getprocs 168but returns an array of 169.Vt kinfo_proc2 170structures. 171Additionally, only the first 172.Fa elemsize 173bytes of each array entry are returned. 174If the size of the 175.Vt kinfo_proc2 176structure increases in size in a future release of 177.Ox , 178the kernel will only return the requested amount of data for 179each array entry and programs that use 180.Fn kvm_getproc2 181will continue to function without the need for recompilation. 182.Pp 183The 184.Fn kvm_getargv2 185and 186.Fn kvm_getenvv2 187functions are equivalents to the 188.Fn kvm_getargv 189and 190.Fn kvm_getenvv 191functions that use a 192.Vt kinfo_proc2 193structure to specify the process. 194.Sh RETURN VALUES 195.Fn kvm_getprocs , 196.Fn kvm_getargv , 197.Fn kvm_getenvv , 198.Fn kvm_getproc2 , 199.Fn kvm_getargv2 , 200and 201.Fn kvm_getenvv2 202all return 203.Dv NULL 204on failure. 205.Sh SEE ALSO 206.Xr kvm 3 , 207.Xr kvm_close 3 , 208.Xr kvm_geterr 3 , 209.Xr kvm_nlist 3 , 210.Xr kvm_open 3 , 211.Xr kvm_openfiles 3 , 212.Xr kvm_read 3 , 213.Xr kvm_write 3 214.Sh BUGS 215These routines do not belong in the 216.Xr kvm 3 217interface. 218