ENVIRON(7)

NAME
environ - user environment

SYNOPSIS
extern char **environ;

DESCRIPTION
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.

EXINIT
    A startup list of commands read by ex(1), edit(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.

MAIL
    The location of the user's mailbox instead of the default in /var/mail, used by mail(1), sh(1), and many other mailclients.

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).

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, termcap(5), and termcap.

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.

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.

SEE ALSO
cd(1), csh(1), ex(1), login(1), sh(1), execve(2), execle(3), setlocale(3), system(3), termcap(3), termcap(5)

HISTORY
The environ manual page appeared in 4.2BSD.