1.\" $NetBSD: environ.7,v 1.8 1999/07/13 14:52:53 kleink Exp $ 2.\" 3.\" Copyright (c) 1983, 1990, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)environ.7 8.3 (Berkeley) 4/19/94 35.\" 36.Dd July 13, 1994 37.Dt ENVIRON 7 38.Os 39.Sh NAME 40.Nm environ 41.Nd user process environment 42.Sh SYNOPSIS 43.Ar extern char **environ ; 44.Sh DESCRIPTION 45An array of strings called the 46.Em environment 47is made available by 48.Xr execve 2 49when a process begins. 50By convention these strings have the form 51.Dq Ar name=value . 52The following names are used by various commands: 53.Bl -tag -width AUDIOCTLDEVICE 54.It Ev AUDIOCTLDEVICE 55The name of the audio control device to be used by 56.Xr audioctl 1 , 57.Xr audioplay 1 58and 59.Xr audiorecord 1 . 60.It Ev AUDIODEVICE 61The name of the audio device to be used by 62.Xr audioplay 1 63and 64.Xr audiorecord 1 . 65.It Ev BLOCKSIZE 66The size of the block units used by several commands, most notably 67.Xr df 1 , 68.Xr du 1 69and 70.Xr ls 1 . 71.Ev BLOCKSIZE 72may be specified in units of a byte by specifying a number, 73in units of a kilobyte by specifying a number followed by ``K'' or 74``k'', in units of a megabyte by specifying a number followed by ``M'' 75or ``m'' and in units of a gigabyte by specifying a number followed 76by ``G'' or ``g''. 77Sizes less than 512 bytes or greater than a gigabyte are ignored. 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 MIXERDEVICE 89The name of the audio mixer device to be used by 90.Xr mixerctl 1 . 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. 98PATH is set to ``/usr/bin:/bin'' initially by 99.Xr login 1 . 100.It Ev PRINTER 101The name of the default printer to be used by 102.Xr lpr 1 , 103.Xr lpq 1 , 104and 105.Xr lprm 1 . 106.It Ev SHELL 107The full pathname of the user's login shell. 108.It Ev TERM 109The kind of terminal for which output is to be prepared. 110This information is used by commands, such as 111.Xr nroff 1 112or 113.Xr plot 1 114which may exploit special terminal capabilities. 115See 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 TERM, or, if 121it begins with a '/', the name of the termcap file. 122See 123.Ev TERMPATH 124below, 125.Xr termcap 5 , 126and 127.Xr termcap 3 . 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. 131Having no 132.Ev TERMPATH 133is equivalent to a 134.Ev TERMPATH 135of 136.Dq Pa $HOME/.termcap:/usr/share/misc/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.Pa /usr/share/zoneinfo . 152For example, the command 153.Ic env TZ=US/Pacific 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.Ic export 164command and 165.Ar name=value 166arguments in 167.Xr sh 1 , 168or by the 169.Ic setenv 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 audioctl 1 , 185.Xr audioplay 1 , 186.Xr audiorecord 1 , 187.Xr csh 1 , 188.Xr ex 1 , 189.Xr login 1 , 190.Xr sh 1 , 191.Xr execve 2 , 192.Xr execle 3 , 193.Xr system 3 , 194.Xr termcap 3 , 195.Xr audio 4 , 196.Xr termcap 5 197.Sh HISTORY 198The 199.Nm 200manual page appeared in 201.Bx 4.2 . 202