ENVIRON(5V)

NAME
environ - user environment

SYNOPSIS
extern char **environ;

DESCRIPTION

An array of strings called the `environment' is made available by execve(2V) when a process begins. By convention these strings have the form `name=value'. The following names are used by various commands:

PATH
    The sequence of directory prefixes that sh(1), time(1V), nice(1), etc., apply in searching for a file known by an incomplete path name. The prefixes are separated by `:'. The login(1) process sets PATH=:/usr/ucb:/bin:/usr/bin.

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

TERM
    The type of terminal on which the user is logged in. This information is used by commands, such as nroff(1) or plot(1G), which may exploit special terminal capabilities. See /etc/termcap (termcap(5)) for a list of terminal types.

SHELL
    The path name of the user's login shell.

TERMCAP
    The string describing the terminal in TERM, or the name of the termcap file, see termcap(3X), termcap(5).

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

USER
LOGNAME
    The user's login name.

TZ  The name of the time zone that the user is located in. If TZ is not present in the environment, the system's default time zone, normally the time zone that the computer is located in, is used.

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). Arguments may also be placed in the environment at the point of an execve(2V). It is unwise to conflict with certain sh(1) variables that are frequently exported by .profile files: MAIL, PS1, PS2, IFS.

Various names are expected to be defined and used by locale dependent commands and functions (see locale(5)).

SYSTEM V DESCRIPTION

The description of the variable TERMCAP does not apply to programs built in the System V environment.

FILES
/etc/passwd
etc/termcap

SEE ALSO
csh(1), ex(1), login(1), nice(1), nroff(1), plot(1G), sh(1), time(1V), vi(1), execve(2V), getenv(3V), system(3), termcap(3X), locale(5), passwd(5), termcap(5)