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.\" $Id: environ.7,v 1.10 1997/03/08 14:41:44 wosch Exp $ 34.\" 35.Dd April 19, 1994 36.Dt ENVIRON 7 37.Os BSD 4.2 38.Sh NAME 39.Nm environ 40.Nd user environment 41.Sh SYNOPSIS 42.Ar extern char **environ ; 43.Sh DESCRIPTION 44An array of strings called the 45.Ar environment 46is made available by 47.Xr execve 2 48when a process begins. By convention these strings have the form 49.Dq Ar name=value . 50The following names are used by various commands: 51.Bl -tag -width BLOCKSIZE 52.It Ev BLOCKSIZE 53The size of the block units used by several commands, most notably 54.Xr df 1 , 55.Xr du 1 56and 57.Xr ls 1 . 58.Ev BLOCKSIZE 59may be specified in units of a byte by specifying a number, 60in units of a kilobyte by specifying a number followed by ``K'' or 61``k'', in units of a megabyte by specifying a number followed by ``M'' 62or ``m'' and in units of a gigabyte by specifying a number followed 63by ``G'' or ``g''. 64Sizes less than 512 bytes or greater than a gigabyte are ignored. 65.It Ev EXINIT 66A startup list of commands read by 67.Xr ex 1 68and 69.Xr vi 1 . 70.It Ev HOME 71A user's login directory, set by 72.Xr login 1 73from the password file 74.Xr passwd 5 . 75.It Ev LANG 76This variable configures all programs which use 77.Xr setlocale 3 78to use the specified locale. 79.It Ev MAIL 80The location of the user's 81mailbox instead of the default in /var/mail, 82used by 83.Xr mail 1 , 84.Xr sh 1 , 85and many other mailclients. 86.It Ev PATH 87The sequence of directories, separated by colons, searched by 88.Xr csh 1 , 89.Xr sh 1 , 90.Xr system 3 , 91.Xr execvp 3 , 92etc, when looking for an executable file. 93.Ev PATH 94is set to ``/usr/bin:/bin'' initially by 95.Xr login 1 . 96.It Ev PRINTER 97The name of the default printer to be used by 98.Xr lpr 1 , 99.Xr lpq 1 , 100and 101.Xr lprm 1 . 102.It Ev SHELL 103The full pathname of the user's login shell. 104.It Ev TERM 105The kind of terminal for which output is to be prepared. 106This information is used by commands, such as 107.Xr nroff 1 108or 109.Xr plot 1 110which may exploit special terminal capabilities. See 111.Pa /usr/share/misc/termcap 112.Pq Xr termcap 5 113for a list of terminal types. 114.It Ev TERMCAP 115The string describing the terminal in 116.Ev TERM , 117or, if 118it begins with a '/', the name of the termcap file. 119See 120.Ev TERMPATH 121below, and 122.Xr termcap 5 . 123.It Ev TERMPATH 124A sequence of pathnames of termcap files, separated by colons or spaces, 125which are searched for terminal descriptions in the order listed. Having 126no 127.Ev TERMPATH 128is equivalent to a 129.Ev TERMPATH 130of 131.Dq Pa $HOME/.termcap:/etc/termcap . 132.Ev TERMPATH 133is ignored if 134.Ev TERMCAP 135contains a full pathname. 136.It Ev TMPDIR 137The directory in which to store temporary files. 138Most applications use either 139.Dq /tmp 140or 141.Dq /var/tmp . 142Setting this variable will make them use another directory. 143.It Ev TZ 144The timezone to use when displaying dates. 145The normal format is a pathname relative to 146.Dq Pa /usr/share/zoneinfo . 147For example, the command 148.Dq env TZ=America/Los_Angeles date 149displays the current time in California. 150See 151.Xr tzset 3 152for more information. 153.It Ev USER 154The login name of the user. 155.El 156.Pp 157Further names may be placed in the environment by the 158.Xr export 159command and 160.Ar name=value 161arguments in 162.Xr sh 1 , 163or by the 164.Xr setenv 165command if you use 166.Xr csh 1 . 167It is unwise to change certain 168.Xr sh 1 169variables that are frequently exported by 170.Pa .profile 171files, such as 172.Ev MAIL , 173.Ev PS1 , 174.Ev PS2 , 175and 176.Ev IFS , 177unless you know what you are doing. 178.Sh SEE ALSO 179.Xr cd 1 , 180.Xr csh 1 , 181.Xr ex 1 , 182.Xr login 1 , 183.Xr sh 1 , 184.Xr execve 2 , 185.Xr execle 3 , 186.Xr setlocale 3 , 187.Xr system 3 , 188.Xr termcap 3 , 189.Xr termcap 5 190.Sh HISTORY 191The 192.Nm environ 193manual page appeared in 194.Bx 4.2 . 195