1.\" $OpenBSD: environ.7,v 1.22 2020/02/09 00:11:23 jsg Exp $ 2.\" $NetBSD: environ.7,v 1.4 1995/07/03 19:45:07 jtc Exp $ 3.\" 4.\" Copyright (c) 1983, 1990, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)environ.7 8.3 (Berkeley) 4/19/94 32.\" 33.Dd $Mdocdate: February 9 2020 $ 34.Dt ENVIRON 7 35.Os 36.Sh NAME 37.Nm environ 38.Nd user environment 39.Sh SYNOPSIS 40.Vt extern char **environ ; 41.Sh DESCRIPTION 42An array of strings called the 43.Dq environment 44is made available by 45.Xr execve 2 46when a process begins. 47By convention these strings have the form 48.Ar name Ns = Ns Ar value . 49The following variables are recognized by various commands: 50.Bl -tag -width BLOCKSIZE 51.It Ev BLOCKSIZE 52The size of the block units used by several commands, most notably 53.Xr df 1 , 54.Xr du 1 , 55and 56.Xr ls 1 . 57May be specified in units of a byte by specifying a number, 58in units of a kilobyte by specifying a number followed by 59.Sq K 60or 61.Sq k , 62in units of a megabyte by specifying a number followed by 63.Sq M 64or 65.Sq m , 66or in units of a gigabyte by specifying a number followed 67by 68.Sq G 69or 70.Sq g . 71Sizes less than 512 bytes or greater than a gigabyte are ignored. 72.It Ev EXINIT 73A list of startup commands read by 74.Xr ex 1 75and 76.Xr vi 1 . 77.It Ev HOME 78The user's login directory, set by 79.Xr login 1 80from the password file 81.Xr passwd 5 . 82.It Ev LOGNAME 83The login name of the user. 84.It Ev PATH 85The sequence of directories, separated by colons, searched by 86.Xr csh 1 , 87.Xr sh 1 , 88.Xr ksh 1 , 89.Xr system 3 , 90.Xr execvp 3 , 91etc. when looking for an executable file. 92Initially set to the value of 93.Dv _PATH_DEFPATH 94by 95.Xr login 1 , 96traditionally 97.Pa /usr/bin:/bin , 98but expanded to include 99.Pa /usr/sbin , 100.Pa /sbin , 101.Pa /usr/X11R6/bin , 102.Pa /usr/local/bin , 103and 104.Pa /usr/local/sbin 105in 106.Ox . 107.It Ev PRINTER 108The name of the default printer to be used by 109.Xr lpq 1 , 110.Xr lpr 1 , 111and 112.Xr lprm 1 . 113.It Ev PWD 114The current working directory. 115.It Ev SHELL 116The full pathname of the user's login shell. 117.It Ev TERM 118The kind of terminal for which output is to be prepared. 119This information is used by commands such as 120.Xr mandoc 1 121which may exploit special terminal capabilities. 122See 123.Pa /usr/share/misc/termcap 124.Pq Xr termcap 5 125for a list of terminal types. 126.It Ev TERMCAP 127The string describing the terminal in 128.Ev TERM , 129or, if it begins with a 130.Ql / , 131the name of the termcap file. 132See 133.Ev TERMPATH 134below, 135.Xr termcap 5 , 136and 137.Xr termcap 3 . 138.It Ev TERMPATH 139A sequence of pathnames of termcap files, separated by colons or spaces, 140which are searched for terminal descriptions in the order listed. 141Having no 142.Ev TERMPATH 143is equivalent to a 144.Ev TERMPATH 145of 146.Pa $HOME/.termcap:/etc/termcap . 147.Ev TERMPATH 148is ignored if 149.Ev TERMCAP 150contains a full pathname. 151.It Ev TMPDIR 152The directory in which to store temporary files. 153Most applications use either 154.Pa /tmp 155or 156.Pa /var/tmp . 157Setting this variable will make them use another directory. 158.It Ev TZ 159The time zone to use when displaying dates. 160The normal format is a pathname relative to 161.Pa /usr/share/zoneinfo . 162For example, the command 163.Ic env TZ=America/Los_Angeles date 164displays the current time in California. 165See 166.Xr tzset 3 167for more information. 168.It Ev USER 169Deprecated synonym of 170.Ev LOGNAME 171(for backwards compatibility). 172.El 173.Pp 174Further names may be placed in the environment by the 175.Ic export 176command and 177.Ar name Ns = Ns Ar value 178arguments in 179.Xr sh 1 , 180or by the 181.Ic setenv 182command if you use 183.Xr csh 1 . 184It is unwise to change certain 185.Xr sh 1 186variables that are frequently exported by 187.Pa .profile 188files, such as 189.Ev MAIL , 190.Ev PS1 , 191.Ev PS2 , 192and 193.Ev IFS , 194unless you know what you are doing. 195.Pp 196The current environment variables can be printed with 197.Xr env 1 198or 199.Xr printenv 1 . 200.Sh SEE ALSO 201.Xr csh 1 , 202.Xr env 1 , 203.Xr ex 1 , 204.Xr login 1 , 205.Xr printenv 1 , 206.Xr sh 1 , 207.Xr execve 2 , 208.Xr execle 3 , 209.Xr getenv 3 , 210.Xr system 3 , 211.Xr termcap 3 , 212.Xr tzset 3 , 213.Xr termcap 5 214.Sh HISTORY 215An 216.Nm 217manual page appeared in 218.At v7 . 219