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28 .\" @(#)environ.7 8.3 (Berkeley) 4/19/94
38 .Ar extern char **environ ;
40 An array of strings, called the
42 is made available to each process by
44 when a process begins.
45 By convention these strings have the form
46 .Va name Ns No = Ns Ar value ,
47 and are referred to as
48 .Dq environment variables .
49 A process can query, update, and delete these strings using the
54 functions, respectively.
55 The shells also provide commands to manipulate the environment;
56 they are described in the respective shell manual pages.
58 What follows is a list of environment variables typically
62 It includes only those variables that a user can expect to see during their
63 day-to-day use of the system, and is far from complete.
64 Environment variables specific to a particular program or library function
67 section of the appropriate manual page.
69 .Bl -tag -width LD_LIBRARY_PATH
71 The size of the block units used by several disk-related commands,
78 may be specified in units of a byte by specifying a number,
79 in units of a kilobyte by specifying a number followed by
83 in units of a megabyte by specifying a number followed by
87 and in units of a gigabyte by specifying a number followed
92 Sizes less than 512 bytes or greater than a gigabyte are ignored.
93 This variable is processed by the
97 The user's preferred width in column positions for the terminal.
102 use this to format output into columns.
103 If unset or empty, utilities will use an
105 call to ask the terminal driver for the width.
109 A startup list of commands read by
114 A user's login directory, set by
116 from the password file
119 This variable configures all programs which use
121 to use the specified locale unless the
125 Overrides the values of
135 Locale to be used for ordering of strings.
137 Locale to be used for character classification
138 (letter, space, digit, etc.) and for interpreting byte sequences as
139 multibyte characters.
141 Locale to be used for diagnostic messages.
143 Locale to be used for interpreting monetary input
144 and formatting output.
146 Locale to be used for interpreting numeric input and
149 Locale to be used for interpreting dates input and
150 for formatting output.
152 The location of the user's
153 mailbox instead of the default in /var/mail,
157 and many other mail clients.
159 The sequence of directories, separated by colons, searched by
161 when looking for manual pages.
163 List of directories to be searched for the message catalog referred to by
168 Default paginator program.
169 The program specified by this variable is used by
173 etc, to display information which is longer than the current display.
175 The sequence of directories, separated by colons, searched by
180 etc, when looking for an executable file.
182 is set to ``/usr/bin:/bin'' initially by
184 .It Ev POSIXLY_CORRECT
185 When set to any value, this environment variable modifies the behaviour
186 of certain commands to (mostly) execute in a strictly POSIX-compliant manner.
188 The name of the default printer to be used by
194 The current directory pathname.
196 The full pathname of the user's login shell.
198 The kind of terminal for which output is to be prepared.
199 This information is used by commands, such as
203 which may exploit special terminal capabilities.
205 .Pa /usr/share/misc/termcap
207 for a list of terminal types.
209 The string describing the terminal in
212 it begins with a '/', the name of the termcap file.
218 A sequence of pathnames of termcap files, separated by colons or spaces,
219 which are searched for terminal descriptions in the order listed.
226 .Pa $HOME/.termcap:/etc/termcap .
230 contains a full pathname.
232 The directory in which to store temporary files.
233 Most applications use either
237 Setting this variable will make them use another directory.
239 The timezone to use when displaying dates.
240 The normal format is a pathname relative to
241 .Pa /usr/share/zoneinfo .
242 For example, the command
244 .Dl env TZ=America/Los_Angeles date
246 displays the current time in California.
249 for more information.
251 The login name of the user.
252 It is recommended that portable applications use
257 Further names may be placed in the environment by the
267 It is unwise to change certain
269 variables that are frequently exported by
277 unless you know what you are doing.
279 The current environment variables can be printed with
313 manual page appeared in