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. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)environ.7 8.3 (Berkeley) 4/19/94 29.\" $FreeBSD: src/share/man/man7/environ.7,v 1.13.2.4 2001/08/17 13:08:49 ru Exp $ 30.\" $DragonFly: src/share/man/man7/environ.7,v 1.4 2007/09/02 19:30:47 swildner Exp $ 31.\" 32.Dd April 19, 1994 33.Dt ENVIRON 7 34.Os 35.Sh NAME 36.Nm environ 37.Nd user environment 38.Sh SYNOPSIS 39.Ar extern char **environ ; 40.Sh DESCRIPTION 41An array of strings called the 42.Ar environment 43is made available by 44.Xr execve 2 45when a process begins. By convention these strings have the form 46.Dq Ar name=value . 47The following names are used by various commands: 48.Bl -tag -width BLOCKSIZE 49.It Ev BLOCKSIZE 50The size of the block units used by several commands, most notably 51.Xr df 1 , 52.Xr du 1 53and 54.Xr ls 1 . 55.Ev BLOCKSIZE 56may be specified in units of a byte by specifying a number, 57in units of a kilobyte by specifying a number followed by ``K'' or 58``k'', in units of a megabyte by specifying a number followed by ``M'' 59or ``m'' and in units of a gigabyte by specifying a number followed 60by ``G'' or ``g''. 61Sizes less than 512 bytes or greater than a gigabyte are ignored. 62.It Ev EDITOR 63Default editor name. 64.It Ev EXINIT 65A startup list of commands read by 66.Xr ex 1 67and 68.Xr vi 1 . 69.It Ev HOME 70A user's login directory, set by 71.Xr login 1 72from the password file 73.Xr passwd 5 . 74.It Ev LANG 75This variable configures all programs which use 76.Xr setlocale 3 77to use the specified locale. 78.It Ev MAIL 79The location of the user's 80mailbox instead of the default in /var/mail, 81used by 82.Xr mail 1 , 83.Xr sh 1 , 84and many other mailclients. 85.It Ev PAGER 86Default paginator program. The program specified by this variable is used by 87.Xr mail 1 , 88.Xr man 1 , 89.Xr ftp 1 , 90etc, to display information which is longer than the current display. 91.It Ev PATH 92The sequence of directories, separated by colons, searched by 93.Xr csh 1 , 94.Xr sh 1 , 95.Xr system 3 , 96.Xr execvp 3 , 97etc, when looking for an executable file. 98.Ev PATH 99is set to ``/usr/bin:/bin'' initially by 100.Xr login 1 . 101.It Ev PRINTER 102The name of the default printer to be used by 103.Xr lpr 1 , 104.Xr lpq 1 , 105and 106.Xr lprm 1 . 107.It Ev PWD 108The current directory pathname. 109.It Ev SHELL 110The full pathname of the user's login shell. 111.It Ev TERM 112The kind of terminal for which output is to be prepared. 113This information is used by commands, such as 114.Xr nroff 1 115which may exploit special terminal capabilities. See 116.Pa /usr/share/misc/termcap 117.Pq Xr termcap 5 118for a list of terminal types. 119.It Ev TERMCAP 120The string describing the terminal in 121.Ev TERM , 122or, if 123it begins with a '/', the name of the termcap file. 124See 125.Ev TERMPATH 126below, and 127.Xr termcap 5 . 128.It Ev TERMPATH 129A sequence of pathnames of termcap files, separated by colons or spaces, 130which are searched for terminal descriptions in the order listed. Having 131no 132.Ev TERMPATH 133is equivalent to a 134.Ev TERMPATH 135of 136.Dq Pa $HOME/.termcap:/etc/termcap . 137.Ev TERMPATH 138is ignored if 139.Ev TERMCAP 140contains a full pathname. 141.It Ev TMPDIR 142The directory in which to store temporary files. 143Most applications use either 144.Pa /tmp 145or 146.Pa /var/tmp . 147Setting this variable will make them use another directory. 148.It Ev TZ 149The timezone to use when displaying dates. 150The normal format is a pathname relative to 151.Dq Pa /usr/share/zoneinfo . 152For example, the command 153.Dq env TZ=America/Los_Angeles date 154displays the current time in California. 155See 156.Xr tzset 3 157for more information. 158.It Ev USER 159The login name of the user. 160.El 161.Pp 162Further names may be placed in the environment by the 163.Xr export 1 164command and 165.Ar name=value 166arguments in 167.Xr sh 1 , 168or by the 169.Xr setenv 1 170command if you use 171.Xr csh 1 . 172It is unwise to change certain 173.Xr sh 1 174variables that are frequently exported by 175.Pa .profile 176files, such as 177.Ev MAIL , 178.Ev PS1 , 179.Ev PS2 , 180and 181.Ev IFS , 182unless you know what you are doing. 183.Sh SEE ALSO 184.Xr cd 1 , 185.Xr csh 1 , 186.Xr ex 1 , 187.Xr login 1 , 188.Xr sh 1 , 189.Xr execve 2 , 190.Xr execle 3 , 191.Xr getenv 3 , 192.Xr setenv 3 , 193.Xr setlocale 3 , 194.Xr system 3 , 195.Xr termcap 3 , 196.Xr termcap 5 197.Sh HISTORY 198The 199.Nm 200manual page appeared in 201.Bx 4.2 . 202