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.\" $FreeBSD$ 34.\" 35.Dd April 12, 2003 36.Dt ENVIRON 7 37.Os 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. 49By convention these strings have the form 50.Dq Ar name=value . 51The following names are used by various commands: 52.Bl -tag -width LC_MONETARY 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 COLUMNS 67The user's preferred width in column positions for the terminal. 68Utilities such as 69.Xr ls 1 70and 71.Xr who 1 72use this to format output into columns. 73If unset or empty, utilities will use an 74.Xr ioctl 2 75call to ask the terminal driver for the width. 76.It Ev EDITOR 77Default editor name. 78.It Ev EXINIT 79A startup list of commands read by 80.Xr ex 1 81and 82.Xr vi 1 . 83.It Ev HOME 84A user's login directory, set by 85.Xr login 1 86from the password file 87.Xr passwd 5 . 88.It Ev LANG 89This variable configures all programs which use 90.Xr setlocale 3 91to use the specified locale unless the 92.Ev LC_* 93variables are set. 94.It Ev LC_ALL 95Overrides the values of 96.Ev LC_COLLATE , 97.Ev LC_CTYPE , 98.Ev LC_MESSAGES , 99.Ev LC_MONETARY , 100.Ev LC_NUMERIC , 101.Ev LC_TIME 102and 103.Ev LANG . 104.It Ev LC_COLLATE 105Locale to be used for ordering of strings. 106.It Ev LC_CTYPE 107Locale to be used for character classification 108(letter, space, digit, etc.) and for interpreting byte sequences as 109multibyte characters. 110.It Ev LC_MESSAGES 111Locale to be used for diagnostic messages. 112.It Ev LC_MONETARY 113Locale to be used for interpreting monetary input 114and formatting output. 115.It Ev LC_NUMERIC 116Locale to be used for interpreting numeric input and 117formatting output. 118.It Ev LC_TIME 119Locale to be used for interpreting dates input and 120for formatting output. 121.It Ev MAIL 122The location of the user's 123mailbox instead of the default in /var/mail, 124used by 125.Xr mail 1 , 126.Xr sh 1 , 127and many other mail clients. 128.It Ev NLSPATH 129List of directories to be searched for the message catalog referred to by 130.Ev LC_MESSAGES . 131See 132.Xr catopen 3 . 133.It Ev PAGER 134Default paginator program. 135The program specified by this variable is used by 136.Xr mail 1 , 137.Xr man 1 , 138.Xr ftp 1 , 139etc, to display information which is longer than the current display. 140.It Ev PATH 141The sequence of directories, separated by colons, searched by 142.Xr csh 1 , 143.Xr sh 1 , 144.Xr system 3 , 145.Xr execvp 3 , 146etc, when looking for an executable file. 147.Ev PATH 148is set to ``/usr/bin:/bin'' initially by 149.Xr login 1 . 150.It Ev PRINTER 151The name of the default printer to be used by 152.Xr lpr 1 , 153.Xr lpq 1 , 154and 155.Xr lprm 1 . 156.It Ev PWD 157The current directory pathname. 158.It Ev SHELL 159The full pathname of the user's login shell. 160.It Ev TERM 161The kind of terminal for which output is to be prepared. 162This information is used by commands, such as 163.Xr nroff 1 164or 165.Xr plot 1 166which may exploit special terminal capabilities. 167See 168.Pa /usr/share/misc/termcap 169.Pq Xr termcap 5 170for a list of terminal types. 171.It Ev TERMCAP 172The string describing the terminal in 173.Ev TERM , 174or, if 175it begins with a '/', the name of the termcap file. 176See 177.Ev TERMPATH 178below, and 179.Xr termcap 5 . 180.It Ev TERMPATH 181A sequence of pathnames of termcap files, separated by colons or spaces, 182which are searched for terminal descriptions in the order listed. 183Having 184no 185.Ev TERMPATH 186is equivalent to a 187.Ev TERMPATH 188of 189.Dq Pa $HOME/.termcap:/etc/termcap . 190.Ev TERMPATH 191is ignored if 192.Ev TERMCAP 193contains a full pathname. 194.It Ev TMPDIR 195The directory in which to store temporary files. 196Most applications use either 197.Dq /tmp 198or 199.Dq /var/tmp . 200Setting this variable will make them use another directory. 201.It Ev TZ 202The timezone to use when displaying dates. 203The normal format is a pathname relative to 204.Dq Pa /usr/share/zoneinfo . 205For example, the command 206.Dq env TZ=America/Los_Angeles date 207displays the current time in California. 208See 209.Xr tzset 3 210for more information. 211.It Ev USER 212The login name of the user. 213.El 214.Pp 215Further names may be placed in the environment by the 216.Ic export 217command and 218.Ar name=value 219arguments in 220.Xr sh 1 , 221or by the 222.Ic setenv 223command if you use 224.Xr csh 1 . 225It is unwise to change certain 226.Xr sh 1 227variables that are frequently exported by 228.Pa .profile 229files, such as 230.Ev MAIL , 231.Ev PS1 , 232.Ev PS2 , 233and 234.Ev IFS , 235unless you know what you are doing. 236.Pp 237The current environment variables can be printed with 238.Xr env 1 , 239.Xr set 1 240or 241.Xr printenv 1 242in 243.Xr sh 1 244and 245.Xr env 1 , 246.Xr printenv 1 247or the 248.Cm printenv 249built-in command in 250.Xr csh 1 . 251.Sh SEE ALSO 252.Xr cd 1 , 253.Xr csh 1 , 254.Xr env 1 , 255.Xr ex 1 , 256.Xr login 1 , 257.Xr printenv 1 , 258.Xr sh 1 , 259.Xr execve 2 , 260.Xr execle 3 , 261.Xr getenv 3 , 262.Xr setenv 3 , 263.Xr setlocale 3 , 264.Xr system 3 , 265.Xr termcap 3 , 266.Xr termcap 5 267.Sh HISTORY 268The 269.Nm 270manual page appeared in 271.Bx 4.2 . 272