1.\" $NetBSD: environ.7,v 1.10 2001/01/03 13:35:11 lukem Exp $ 2.\" 3.\" Copyright (c) 1983, 1990, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)environ.7 8.3 (Berkeley) 4/19/94 35.\" 36.Dd January 4, 2001 37.Dt ENVIRON 7 38.Os 39.Sh NAME 40.Nm environ 41.Nd user process environment 42.Sh SYNOPSIS 43.Ar extern char **environ ; 44.Sh DESCRIPTION 45An array of strings called the 46.Em environment 47is made available by 48.Xr execve 2 49when a process begins. 50By convention these strings have the form 51.Dq Ar name=value . 52The following names are used by various commands: 53.Bl -tag -width LIBC_DIAGASSERT 54.It Ev AUDIOCTLDEVICE 55The name of the audio control device to be used by 56.Xr audioctl 1 , 57.Xr audioplay 1 58and 59.Xr audiorecord 1 . 60.It Ev AUDIODEVICE 61The name of the audio device to be used by 62.Xr audioplay 1 63and 64.Xr audiorecord 1 . 65.It Ev BLOCKSIZE 66The size of the block units used by several commands, most notably 67.Xr df 1 , 68.Xr du 1 69and 70.Xr ls 1 . 71.Ev BLOCKSIZE 72may be specified in units of a byte by specifying a number, 73in units of a kilobyte by specifying a number followed by 74.Dq K 75or 76.Dq k , 77in units of a megabyte by specifying a number followed by 78.Dq M 79or 80.Dq m 81and in units of a gigabyte by specifying a number followed 82by 83.Dq G 84or 85.Dq g . 86Sizes less than 512 bytes or greater than a gigabyte are ignored. 87.It Ev EXINIT 88A startup list of commands read by 89.Xr ex 1 90and 91.Xr vi 1 . 92.It Ev HOME 93A user's login directory, set by 94.Xr login 1 95from the password file 96.Xr passwd 5 . 97.It Ev LIBC_DIAGASSERT 98Control how the 99.Fn _DIAGASSERT 100macro (from 101.Pa <assert.h> ) 102behaves once the assertion is raised. 103Refer to 104.Xr _DIAGASSERT 3 105for more information. 106.It Ev MALLOC_OPTIONS 107Control the behaviour of the 108.Fn malloc 109function. 110Refer to 111.Xr malloc 3 112for more information. 113.It Ev MIXERDEVICE 114The name of the audio mixer device to be used by 115.Xr mixerctl 1 . 116.It Ev PATH 117The sequence of directories, separated by colons, searched by 118.Xr csh 1 , 119.Xr sh 1 , 120.Xr system 3 , 121.Xr execvp 3 , 122etc, when looking for an executable file. 123PATH is set to 124.Dq /usr/bin:/bin:/usr/pkg/bin:/usr/local/bin 125initially by 126.Xr login 1 . 127.It Ev PRINTER 128The name of the default printer to be used by 129.Xr lpr 1 , 130.Xr lpq 1 , 131and 132.Xr lprm 1 . 133.It Ev SHELL 134The full pathname of the user's login shell. 135.It Ev TERM 136The kind of terminal for which output is to be prepared. 137This information is used by commands, such as 138.Xr nroff 1 139or 140.Xr plot 1 141which may exploit special terminal capabilities. 142See 143.Pa /usr/share/misc/termcap 144.Pq Xr termcap 5 145for a list of terminal types. 146.It Ev TERMCAP 147The string describing the terminal in TERM, or, if 148it begins with a '/', the name of the termcap file. 149See 150.Ev TERMPATH 151below, 152.Xr termcap 5 , 153and 154.Xr termcap 3 . 155.It Ev TERMPATH 156A sequence of pathnames of termcap files, separated by colons or spaces, 157which are searched for terminal descriptions in the order listed. 158Having no 159.Ev TERMPATH 160is equivalent to a 161.Ev TERMPATH 162of 163.Dq Pa $HOME/.termcap:/usr/share/misc/termcap . 164.Ev TERMPATH 165is ignored if 166.Ev TERMCAP 167contains a full pathname. 168.It Ev TMPDIR 169The directory in which to store temporary files. 170Most applications use either 171.Pa /tmp 172or 173.Pa /var/tmp . 174Setting this variable will make them use another directory. 175.It Ev TZ 176The timezone to use when displaying dates. 177The normal format is a pathname relative to 178.Pa /usr/share/zoneinfo . 179For example, the command 180.Ic env TZ=US/Pacific date 181displays the current time in California. 182See 183.Xr tzset 3 184for more information. 185.It Ev USER 186The login name of the user. 187.El 188.Pp 189Further names may be placed in the environment by the 190.Ic export 191command and 192.Ar name=value 193arguments in 194.Xr sh 1 , 195or by the 196.Ic setenv 197command if you use 198.Xr csh 1 . 199It is unwise to change certain 200.Xr sh 1 201variables that are frequently exported by 202.Pa .profile 203files, such as 204.Ev MAIL , 205.Ev PS1 , 206.Ev PS2 , 207and 208.Ev IFS , 209unless you know what you are doing. 210.Sh SEE ALSO 211.Xr audioctl 1 , 212.Xr audioplay 1 , 213.Xr audiorecord 1 , 214.Xr csh 1 , 215.Xr ex 1 , 216.Xr login 1 , 217.Xr sh 1 , 218.Xr execve 2 , 219.Xr _DIAGASSERT 3 , 220.Xr execle 3 , 221.Xr malloc 3 , 222.Xr system 3 , 223.Xr termcap 3 , 224.Xr audio 4 , 225.Xr termcap 5 226.Sh HISTORY 227The 228.Nm 229manual page appeared in 230.Bx 4.2 . 231