1.\" Copyright (c) 1983, 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 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.\" @(#)environ.7 8.3 (Berkeley) 4/19/94 33.\" $FreeBSD: src/share/man/man7/environ.7,v 1.13.2.4 2001/08/17 13:08:49 ru Exp $ 34.\" $DragonFly: src/share/man/man7/environ.7,v 1.4 2007/09/02 19:30:47 swildner Exp $ 35.\" 36.Dd April 19, 1994 37.Dt ENVIRON 7 38.Os 39.Sh NAME 40.Nm environ 41.Nd user environment 42.Sh SYNOPSIS 43.Ar extern char **environ ; 44.Sh DESCRIPTION 45An array of strings called the 46.Ar environment 47is made available by 48.Xr execve 2 49when a process begins. By convention these strings have the form 50.Dq Ar name=value . 51The following names are used by various commands: 52.Bl -tag -width BLOCKSIZE 53.It Ev BLOCKSIZE 54The size of the block units used by several commands, most notably 55.Xr df 1 , 56.Xr du 1 57and 58.Xr ls 1 . 59.Ev BLOCKSIZE 60may be specified in units of a byte by specifying a number, 61in units of a kilobyte by specifying a number followed by ``K'' or 62``k'', in units of a megabyte by specifying a number followed by ``M'' 63or ``m'' and in units of a gigabyte by specifying a number followed 64by ``G'' or ``g''. 65Sizes less than 512 bytes or greater than a gigabyte are ignored. 66.It Ev EDITOR 67Default editor name. 68.It Ev EXINIT 69A startup list of commands read by 70.Xr ex 1 71and 72.Xr vi 1 . 73.It Ev HOME 74A user's login directory, set by 75.Xr login 1 76from the password file 77.Xr passwd 5 . 78.It Ev LANG 79This variable configures all programs which use 80.Xr setlocale 3 81to use the specified locale. 82.It Ev MAIL 83The location of the user's 84mailbox instead of the default in /var/mail, 85used by 86.Xr mail 1 , 87.Xr sh 1 , 88and many other mailclients. 89.It Ev PAGER 90Default paginator program. The program specified by this variable is used by 91.Xr mail 1 , 92.Xr man 1 , 93.Xr ftp 1 , 94etc, to display information which is longer than the current display. 95.It Ev PATH 96The sequence of directories, separated by colons, searched by 97.Xr csh 1 , 98.Xr sh 1 , 99.Xr system 3 , 100.Xr execvp 3 , 101etc, when looking for an executable file. 102.Ev PATH 103is set to ``/usr/bin:/bin'' initially by 104.Xr login 1 . 105.It Ev PRINTER 106The name of the default printer to be used by 107.Xr lpr 1 , 108.Xr lpq 1 , 109and 110.Xr lprm 1 . 111.It Ev PWD 112The current directory pathname. 113.It Ev SHELL 114The full pathname of the user's login shell. 115.It Ev TERM 116The kind of terminal for which output is to be prepared. 117This information is used by commands, such as 118.Xr nroff 1 119which may exploit special terminal capabilities. See 120.Pa /usr/share/misc/termcap 121.Pq Xr termcap 5 122for a list of terminal types. 123.It Ev TERMCAP 124The string describing the terminal in 125.Ev TERM , 126or, if 127it begins with a '/', the name of the termcap file. 128See 129.Ev TERMPATH 130below, and 131.Xr termcap 5 . 132.It Ev TERMPATH 133A sequence of pathnames of termcap files, separated by colons or spaces, 134which are searched for terminal descriptions in the order listed. Having 135no 136.Ev TERMPATH 137is equivalent to a 138.Ev TERMPATH 139of 140.Dq Pa $HOME/.termcap:/etc/termcap . 141.Ev TERMPATH 142is ignored if 143.Ev TERMCAP 144contains a full pathname. 145.It Ev TMPDIR 146The directory in which to store temporary files. 147Most applications use either 148.Pa /tmp 149or 150.Pa /var/tmp . 151Setting this variable will make them use another directory. 152.It Ev TZ 153The timezone to use when displaying dates. 154The normal format is a pathname relative to 155.Dq Pa /usr/share/zoneinfo . 156For example, the command 157.Dq env TZ=America/Los_Angeles date 158displays the current time in California. 159See 160.Xr tzset 3 161for more information. 162.It Ev USER 163The login name of the user. 164.El 165.Pp 166Further names may be placed in the environment by the 167.Xr export 1 168command and 169.Ar name=value 170arguments in 171.Xr sh 1 , 172or by the 173.Xr setenv 1 174command if you use 175.Xr csh 1 . 176It is unwise to change certain 177.Xr sh 1 178variables that are frequently exported by 179.Pa .profile 180files, such as 181.Ev MAIL , 182.Ev PS1 , 183.Ev PS2 , 184and 185.Ev IFS , 186unless you know what you are doing. 187.Sh SEE ALSO 188.Xr cd 1 , 189.Xr csh 1 , 190.Xr ex 1 , 191.Xr login 1 , 192.Xr sh 1 , 193.Xr execve 2 , 194.Xr execle 3 , 195.Xr getenv 3 , 196.Xr setenv 3 , 197.Xr setlocale 3 , 198.Xr system 3 , 199.Xr termcap 3 , 200.Xr termcap 5 201.Sh HISTORY 202The 203.Nm 204manual page appeared in 205.Bx 4.2 . 206