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: head/share/man/man7/environ.7 243117 2012-11-16 01:43:23Z grog $ 30.\" 31.Dd November 24, 2013 32.Dt ENVIRON 7 33.Os 34.Sh NAME 35.Nm environ 36.Nd user environment 37.Sh SYNOPSIS 38.Ar extern char **environ ; 39.Sh DESCRIPTION 40An array of strings called the 41.Ar environment 42is made available by 43.Xr execve 2 44when a process begins. 45By convention these strings have the form 46.Dq Ar name=value . 47The following names are used by various commands: 48.Bl -tag -width ".Ev LC_MONETARY" 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 . 55This variable is processed by the 56.Xr getbsize 3 57function. 58.It Ev COLUMNS 59The user's preferred width in column positions for the terminal. 60Utilities such as 61.Xr ls 1 62and 63.Xr who 1 64use this to format output into columns. 65If unset or empty, utilities will use an 66.Xr ioctl 2 67call to ask the terminal driver for the width. 68.It Ev EDITOR 69Default editor name. 70.It Ev EXINIT 71A startup list of commands read by 72.Xr ex 1 73and 74.Xr vi 1 . 75.It Ev HOME 76A user's login directory, set by 77.Xr login 1 78from the password file 79.Xr passwd 5 . 80.It Ev LANG 81This variable configures all programs which use 82.Xr setlocale 3 83to use the specified locale unless the 84.Ev LC_* 85variables are set. 86.It Ev LC_ALL 87Overrides the values of 88.Ev LC_COLLATE , 89.Ev LC_CTYPE , 90.Ev LC_MESSAGES , 91.Ev LC_MONETARY , 92.Ev LC_NUMERIC , 93.Ev LC_TIME 94and 95.Ev LANG . 96.It Ev LC_COLLATE 97Locale to be used for ordering of strings. 98.It Ev LC_CTYPE 99Locale to be used for character classification 100(letter, space, digit, etc.) and for interpreting byte sequences as 101multibyte characters. 102.It Ev LC_MESSAGES 103Locale to be used for diagnostic messages. 104.It Ev LC_MONETARY 105Locale to be used for interpreting monetary input 106and formatting output. 107.It Ev LC_NUMERIC 108Locale to be used for interpreting numeric input and 109formatting output. 110.It Ev LC_TIME 111Locale to be used for interpreting dates input and 112for formatting output. 113.It Ev MAIL 114The location of the user's 115mailbox instead of the default in /var/mail, 116used by 117.Xr mail 1 , 118.Xr sh 1 , 119and many other mail clients. 120.It Ev NLSPATH 121List of directories to be searched for the message catalog referred to by 122.Ev LC_MESSAGES . 123See 124.Xr catopen 3 . 125.It Ev PAGER 126Default paginator program. 127The program specified by this variable is used by 128.Xr mail 1 , 129.Xr man 1 , 130.Xr ftp 1 , 131etc, to display information which is longer than the current display. 132.It Ev PATH 133The sequence of directories, separated by colons, searched by 134.Xr csh 1 , 135.Xr sh 1 , 136.Xr system 3 , 137.Xr execvp 3 , 138etc, when looking for an executable file. 139.Ev PATH 140is set to ``/usr/bin:/bin'' initially by 141.Xr login 1 . 142.It Ev PRINTER 143The name of the default printer to be used by 144.Xr lpr 1 , 145.Xr lpq 1 , 146and 147.Xr lprm 1 . 148.It Ev PWD 149The current directory pathname. 150.It Ev SHELL 151The full pathname of the user's login shell. 152.It Ev TERM 153The kind of terminal for which output is to be prepared. 154This information is used by commands, such as 155.Xr nroff 1 156which may exploit special terminal capabilities. 157See 158.Pa /usr/share/misc/termcap 159.Pq Xr termcap 5 160for a list of terminal types. 161.It Ev TERMCAP 162The string describing the terminal in 163.Ev TERM , 164or, if 165it begins with a '/', the name of the termcap file. 166See 167.Ev TERMPATH 168below, and 169.Xr termcap 5 . 170.It Ev TERMPATH 171A sequence of pathnames of termcap files, separated by colons or spaces, 172which are searched for terminal descriptions in the order listed. 173Having 174no 175.Ev TERMPATH 176is equivalent to a 177.Ev TERMPATH 178of 179.Dq Pa $HOME/.termcap:/etc/termcap . 180.Ev TERMPATH 181is ignored if 182.Ev TERMCAP 183contains a full pathname. 184.It Ev TMPDIR 185The directory in which to store temporary files. 186Most applications use either 187.Pa /tmp 188or 189.Pa /var/tmp . 190Setting this variable will make them use another directory. 191.It Ev TZ 192The timezone to use when displaying dates. 193The normal format is a pathname relative to 194.Dq Pa /usr/share/zoneinfo . 195For example, the command 196.Dq env TZ=America/Los_Angeles date 197displays the current time in California. 198See 199.Xr tzset 3 200for more information. 201.It Ev USER 202The login name of the user. 203.El 204.Pp 205Further names may be placed in the environment by the 206.Xr export 1 207command and 208.Ar name=value 209arguments in 210.Xr sh 1 , 211or by the 212.Xr setenv 1 213command if you use 214.Xr csh 1 . 215It is unwise to change certain 216.Xr sh 1 217variables that are frequently exported by 218.Pa .profile 219files, such as 220.Ev MAIL , 221.Ev PS1 , 222.Ev PS2 , 223and 224.Ev IFS , 225unless you know what you are doing. 226.Pp 227The current environment variables can be printed with 228.Xr env 1 , 229.Xr set 1 230or 231.Xr printenv 1 232in 233.Xr sh 1 234and 235.Xr env 1 , 236.Xr printenv 1 237or the 238.Cm printenv 239built-in command in 240.Xr csh 1 . 241.Sh SEE ALSO 242.Xr cd 1 , 243.Xr csh 1 , 244.Xr env 1 , 245.Xr ex 1 , 246.Xr login 1 , 247.Xr printenv 1 , 248.Xr sh 1 , 249.Xr execve 2 , 250.Xr execle 3 , 251.Xr getbsize 3 , 252.Xr getenv 3 , 253.Xr setenv 3 , 254.Xr setlocale 3 , 255.Xr system 3 , 256.Xr termcap 3 , 257.Xr termcap 5 , 258.Xr nls 7 259.Sh HISTORY 260The 261.Nm 262manual page appeared in 263.Bx 4.2 . 264