ENVIRON(7) FreeBSD Miscellaneous Information Manual ENVIRON(7)
NAME
environ - user environment
SYNOPSIS
extern char **environ;
DESCRIPTION
An array of strings, called the environment is made available to each
process by execve(2) when a process begins. By convention these strings
have the form name=value, and are referred to as "environment variables".
A process can query, update, and delete these strings using the
getenv(3), setenv(3), and unsetenv(3) functions, respectively. The
shells also provide commands to manipulate the environment; they are
described in the respective shell manual pages.
What follows is a list of environment variables typically seen on a UNIX
system. It includes only those variables that a user can expect to see
during their day-to-day use of the system, and is far from complete.
Environment variables specific to a particular program or library
function are documented in the ENVIRONMENT section of the appropriate
manual page.
ENVIRONMENT
BLOCKSIZE The size of the block units used by several disk-related
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. This variable is
processed by the getbsize(3) function.
COLUMNS The user's preferred width in column positions for the
terminal. Utilities such as ls(1) and who(1) use this
to format output into columns. If unset or empty,
utilities will use an ioctl(2) call to ask the terminal
driver for the width.
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 file passwd(5).
LANG This variable configures all programs which use
setlocale(3) to use the specified locale unless the LC_*
variables are set.
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 multibyte characters.
LC_MESSAGES Locale to be used for diagnostic messages.
LC_MONETARY Locale to be used for interpreting monetary input and
formatting output.
LC_NUMERIC Locale to be used for interpreting numeric input and
formatting output.
LC_TIME Locale to be used for interpreting dates input and for
formatting output.
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 clients.
MANPATH The sequence of directories, separated by colons,
searched by man(1) when looking for manual pages.
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).
POSIXLY_CORRECT When set to any value, this environment variable
modifies the behaviour of certain commands to (mostly)
execute in a strictly POSIX-compliant manner.
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 terminal types.
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
descriptions 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
format is a pathname relative to /usr/share/zoneinfo.
For example, the command
env TZ=America/Los_Angeles date
displays the current time in California. See tzset(3)
for more information.
USER The login name of the user. It is recommended that
portable applications use LOGNAME instead.
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
frequently 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 ALSO
cd(1), csh(1), env(1), ex(1), login(1), printenv(1), sh(1), execve(2),
execle(3), getbsize(3), getenv(3), setenv(3), setlocale(3), system(3),
termcap(3), termcap(5)
HISTORY
The environ manual page appeared in Version 7 AT&T UNIX.
FreeBSD 13.1-RELEASE-p6 August 5, 2020 FreeBSD 13.1-RELEASE-p6
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