xref: /freebsd/share/man/man7/environ.7 (revision d37ea99837e6ad50837fd9fe1771ddf1c3ba6002)
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32.\"	@(#)environ.7	8.3 (Berkeley) 4/19/94
33.\" $FreeBSD$
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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.  By convention these strings have the form
49.Dq Ar name=value .
50The following names are used by various commands:
51.Bl -tag -width LC_MONETARY
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 COLUMNS
66The user's preferred width in column positions for the terminal.
67Utilities such as
68.Xr ls 1
69and
70.Xr who 1
71use this to format output into columns.
72If unset or empty, utilities will use an
73.Xr ioctl 2
74call to ask the terminal driver for the width.
75.It Ev EDITOR
76Default editor name.
77.It Ev EXINIT
78A startup list of commands read by
79.Xr ex  1
80and
81.Xr vi  1  .
82.It Ev HOME
83A user's login directory, set by
84.Xr login  1
85from the password file
86.Xr passwd  5  .
87.It Ev LANG
88This variable configures all programs which use
89.Xr setlocale 3
90to use the specified locale unless the
91.Ev LC_*
92variables are set.
93.It Ev LC_ALL
94Overrides the values of
95.Ev LC_COLLATE ,
96.Ev LC_CTYPE ,
97.Ev LC_MESSAGES ,
98.Ev LC_MONETARY ,
99.Ev LC_NUMERIC ,
100.Ev LC_TIME
101and
102.Ev LANG .
103.It Ev LC_COLLATE
104Locale to be used for ordering of strings.
105.It Ev LC_CTYPE
106Locale to be used for character classification
107(letter, space, digit, etc.) and for interpreting byte sequences as
108multibyte characters.
109.It Ev LC_MESSAGES
110Locale to be used for diagnostic messages.
111.It Ev LC_MONETARY
112Locale to be used for interpreting monetary input
113and formatting output.
114.It Ev LC_NUMERIC
115Locale to be used for interpreting numeric input and
116formatting output.
117.It Ev LC_TIME
118Locale to be used for interpreting dates input and
119for formatting output.
120.It Ev MAIL
121The location of the user's
122mailbox instead of the default in /var/mail,
123used by
124.Xr mail  1 ,
125.Xr sh 1 ,
126and many other mailclients.
127.It Ev NLSPATH
128List of directories to be searched for the message catalog referred to by
129.Ev LC_MESSAGES .
130See
131.Xr catopen 3 .
132.It Ev PAGER
133Default paginator program.  The program specified by this variable is used by
134.Xr mail 1 ,
135.Xr man 1 ,
136.Xr ftp 1 ,
137etc, to display information which is longer than the current display.
138.It Ev PATH
139The sequence of directories, separated by colons, searched by
140.Xr csh  1  ,
141.Xr sh  1 ,
142.Xr system  3  ,
143.Xr execvp  3 ,
144etc, when looking for an executable file.
145.Ev PATH
146is set to ``/usr/bin:/bin'' initially by
147.Xr login  1  .
148.It Ev PRINTER
149The name of the default printer to be used by
150.Xr lpr  1  ,
151.Xr lpq  1 ,
152and
153.Xr lprm  1  .
154.It Ev PWD
155The current directory pathname.
156.It Ev SHELL
157The full pathname of the user's login shell.
158.It Ev TERM
159The kind of terminal for which output is to be prepared.
160This information is used by commands, such as
161.Xr nroff  1
162or
163.Xr plot 1
164which may exploit special terminal capabilities.  See
165.Pa /usr/share/misc/termcap
166.Pq Xr termcap 5
167for a list of terminal types.
168.It Ev TERMCAP
169The string describing the terminal in
170.Ev TERM ,
171or, if
172it begins with a '/', the name of the termcap file.
173See
174.Ev TERMPATH
175below, and
176.Xr termcap  5 .
177.It Ev TERMPATH
178A sequence of pathnames of termcap files, separated by colons or spaces,
179which are searched for terminal descriptions in the order listed.  Having
180no
181.Ev TERMPATH
182is equivalent to a
183.Ev TERMPATH
184of
185.Dq Pa $HOME/.termcap:/etc/termcap .
186.Ev TERMPATH
187is ignored if
188.Ev TERMCAP
189contains a full pathname.
190.It Ev TMPDIR
191The directory in which to store temporary files.
192Most applications use either
193.Dq /tmp
194or
195.Dq /var/tmp .
196Setting this variable will make them use another directory.
197.It Ev TZ
198The timezone to use when displaying dates.
199The normal format is a pathname relative to
200.Dq Pa /usr/share/zoneinfo .
201For example, the command
202.Dq env TZ=America/Los_Angeles date
203displays the current time in California.
204See
205.Xr tzset 3
206for more information.
207.It Ev USER
208The login name of the user.
209.El
210.Pp
211Further names may be placed in the environment by the
212.Ic export
213command and
214.Ar name=value
215arguments in
216.Xr sh  1  ,
217or by the
218.Ic setenv
219command if you use
220.Xr csh  1  .
221It is unwise to change certain
222.Xr sh  1
223variables that are frequently exported by
224.Pa .profile
225files, such as
226.Ev MAIL ,
227.Ev PS1 ,
228.Ev PS2 ,
229and
230.Ev IFS ,
231unless you know what you are doing.
232.Sh SEE ALSO
233.Xr cd 1 ,
234.Xr csh 1 ,
235.Xr env 1 ,
236.Xr ex 1 ,
237.Xr login 1 ,
238.Xr sh 1 ,
239.Xr execve 2 ,
240.Xr execle 3 ,
241.Xr getenv 3 ,
242.Xr setenv 3 ,
243.Xr setlocale 3 ,
244.Xr system 3 ,
245.Xr termcap 3 ,
246.Xr termcap 5
247.Sh HISTORY
248The
249.Nm
250manual page appeared in
251.Bx 4.2 .
252