ENVIRON(5) ENVIRON(5)
NAME
environ - user environment
SYNOPSIS
extern char **environ;
DESCRIPTION
An array of strings called the `environment' is made avail-
able by exec(2) when a process begins. By convention these
strings have either the form `name=value', defining a vari-
able, or `name(){value}', defining a function (see sh(1)).
The following variables are used by various commands:
PATH The sequence of directory prefixes that sh, time,
nice(1), etc., apply in searching for a file known
by an incomplete path name. The prefixes are sepa-
rated by `:'. Login(1) sets PATH=:/bin:/usr/bin.
HOME A user's login directory, set by login(8) from the
password file passwd(5).
TERM The kind of terminal for which output is to be pre-
pared. This information is used by commands, such
as nroff or plot(1), which may exploit special ter-
minal capabilities. See /etc/termcap for a list of
terminal types.
SHELL The name of the login shell.
The environment may be queried by getenv(3) or by the set or
whatis commands of sh(1). Names may be placed in the envi-
ronment by the export command by and `name=value' arguments
in sh(1). Names may also be placed in the environment at the
point of an exec(2). It is unwise to conflict with certain
sh(1) variables that are frequently exported by `.profile'
files: MAIL, PS1, PS2, IFS.
SEE ALSO
sh(1), exec(2), getenv(3), term(7)