ENVIRON(7) BSD Miscellaneous Information Manual ENVIRON(7)NAMEenviron — user environment
extern char **environ;
An array of strings called the environment is made available by execve(2)
when a process begins. By convention these strings have the form
“name=value”. The following names are used by various commands:
BLOCKSIZE The size of the block units used by several commands, most
notably df(1), du(1) and ls(1). BLOCKSIZE may be specified
in units of a byte by specifying a number, in units of a
kilobyte by specifying a number followed by ``K'' or ``k'',
in units of a megabyte by specifying a number followed by
``M'' or ``m'' and in units of a gigabyte by specifying a
number followed by ``G'' or ``g''. Sizes less than 512
bytes or greater than a gigabyte are ignored.
COLUMNS The user's preferred width in column positions for the ter‐
minal. Utilities such as ls(1) and who(1) use this to for‐
mat output into columns. If unset or empty, utilities will
use an ioctl(2) call to ask the terminal driver for the
EDITOR Default editor name.
EXINIT A startup list of commands read by ex(1) and vi(1).
HOME A user's login directory, set by login(1) from the password
LANG This variable configures all programs which use setlocale(3)
to use the specified locale unless the LC_* variables are
LC_ALL Overrides the values of LC_COLLATE, LC_CTYPE, LC_MESSAGES,
LC_MONETARY, LC_NUMERIC, LC_TIME and LANG.
LC_COLLATE Locale to be used for ordering of strings.
LC_CTYPE Locale to be used for character classification (letter,
space, digit, etc.) and for interpreting byte sequences as
LC_MESSAGES Locale to be used for diagnostic messages.
LC_MONETARY Locale to be used for interpreting monetary input and for‐
LC_NUMERIC Locale to be used for interpreting numeric input and format‐
LC_TIME Locale to be used for interpreting dates input and for for‐
MAIL The location of the user's mailbox instead of the default in
/var/mail, used by mail(1), sh(1), and many other mail
NLSPATH List of directories to be searched for the message catalog
referred to by LC_MESSAGES. See catopen(3).
PAGER Default paginator program. The program specified by this
variable is used by mail(1), man(1), ftp(1), etc, to display
information which is longer than the current display.
PATH The sequence of directories, separated by colons, searched
by csh(1), sh(1), system(3), execvp(3), etc, when looking
for an executable file. PATH is set to ``/usr/bin:/bin''
initially by login(1).
PRINTER The name of the default printer to be used by lpr(1),
lpq(1), and lprm(1).
PWD The current directory pathname.
SHELL The full pathname of the user's login shell.
TERM The kind of terminal for which output is to be prepared.
This information is used by commands, such as nroff(1) or
plot(1) which may exploit special terminal capabilities.
See /usr/share/misc/termcap (termcap(5)) for a list of ter‐
TERMCAP The string describing the terminal in TERM, or, if it begins
with a '/', the name of the termcap file. See TERMPATH
below, and termcap(5).
TERMPATH A sequence of pathnames of termcap files, separated by
colons or spaces, which are searched for terminal descrip‐
tions in the order listed. Having no TERMPATH is equivalent
to a TERMPATH of “$HOME/.termcap:/etc/termcap”. TERMPATH is
ignored if TERMCAP contains a full pathname.
TMPDIR The directory in which to store temporary files. Most
applications use either “/tmp” or “/var/tmp”. Setting this
variable will make them use another directory.
TZ The timezone to use when displaying dates. The normal for‐
mat is a pathname relative to “/usr/share/zoneinfo”. For
example, the command “env TZ=America/Los_Angeles date” dis‐
plays the current time in California. See tzset(3) for more
USER The login name of the user.
Further names may be placed in the environment by the export command and
name=value arguments in sh(1), or by the setenv command if you use
csh(1). It is unwise to change certain sh(1) variables that are fre‐
quently exported by .profile files, such as MAIL, PS1, PS2, and IFS,
unless you know what you are doing.
The current environment variables can be printed with env(1), set(1) or
printenv(1) in sh(1) and env(1), printenv(1) or the printenv built-in
command in csh(1).
SEE ALSOcd(1), csh(1), env(1), ex(1), login(1), printenv(1), sh(1), execve(2),
execle(3), getenv(3), setenv(3), setlocale(3), system(3), termcap(3),
The environ manual page appeared in 4.2BSD.
BSD April 12, 2003 BSD