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 variables are recognized by various commands:

BLOCKSIZE
    The size of the block units used by several commands, most notably df(1), du(1), and ls(1). 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’, or 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 list of startup commands read by ex(1) and vi(1).

HOME
    The user's login directory, set by login(1) from the password file passwd(5).

LOGNAME
    The login name of the user.

PATH
    The sequence of directories, separated by colons, searched by csh(1), sh(1), ksh(1), system(3), execvp(3), etc. when looking for an executable file. Initially set to the value of _PATH_DEFPATH by login(1), traditionally /usr/bin:/bin, but expanded to include /usr/sbin, /sbin, /usr/X11R6/bin, /usr/local/bin, and /usr/local/sbin in OpenBSD.

PRINTER
    The name of the default printer to be used by lpq(1), lpr(1), and lprm(1).

PWD The current working directory.

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 mandoc(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(3).

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 time zone 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
    Deprecated synonym of LOGNAME (for backwards compatibility).

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) or printenv(1).

SEE ALSO
csh(1), env(1), ex(1), login(1), printenv(1), sh(1), execve(2), execle(3), getenv(3), system(3), termcap(3), tzset(3), termcap(5)

HISTORY
An environ manual page appeared in AT&T UNIX.