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