term% cat index.txt ENVIRON(5) File Formats Manual ENVIRON(5)
NAME
environ - user environment
SYNOPSIS
extern char **environ;
DESCRIPTION
An array of strings called the `environment' is made available by
exec(2) when a process begins. By convention these strings have either
the form `name=value', defining a variable, or `name(){value}', defin‐
ing a function (see sh(1)). The following variables are used by vari‐
ous 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 separated 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 prepared. This
information is used by commands, such as nroff or plot(1),
which may exploit special terminal 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 environment by the ex‐
port 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)
ENVIRON(5)