ENVIRON(5)          UNIX Programmer's Manual           ENVIRON(5)

NAME
     environ - user environment

SYNOPSIS
     extern char **environ;

DESCRIPTION
     An array of strings called the `environment' is made avail-
     able by _e_x_e_c_v_e(2) when a process begins.  By convention
     these strings have the form `_n_a_m_e=_v_a_l_u_e'.  The following
     names are used by various commands:

     PATH    The sequence of directory prefixes that _s_h, _t_i_m_e,
             _n_i_c_e(1), etc., apply in searching for a file known
             by an incomplete path name.  The prefixes are
             separated by `:'.  _L_o_g_i_n(1) sets
             PATH=:/bin:/usr/ucb:/usr/bin.

     HOME    A user's login directory, set by _l_o_g_i_n(1) from the
             password file _p_a_s_s_w_d(5).

     SHELL   The name of the user's login shell, set by _l_o_g_i_n(1)
             from the password file _p_a_s_s_w_d(5).

     TERM    The kind of terminal for which output is to be
             prepared.  This information is used by commands,
             such as _n_r_o_f_f or _p_l_o_t(1), which may exploit special
             terminal capabilities.  See /_e_t_c/_t_e_r_m_c_a_p
             (_t_e_r_m_c_a_p(5)) for a list of terminal types.

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

     EXINIT  A startup list of commands read by _e_x(1), _e_d_i_t(1),
             and _v_i(1).

     USER    The login name of the user.

     Further names may be placed in the environment by the _e_x_p_o_r_t
     command and `name=value' arguments in _s_h(1), or by the
     _s_e_t_e_n_v command if you use _c_s_h(1).  Arguments may also be
     placed in the environment at the point of an _e_x_e_c_v_e(2).  It
     is unwise to conflict with certain _s_h(1) variables that are
     frequently exported by `.profile' files: MAIL, PS1, PS2,
     IFS.

SEE ALSO
     csh(1), ex(1), login(1), sh(1), execve(2), exec(3),
     system(3S), termcap(3X), termcap(5)

Printed 5/26/83                                                 1