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 names are used by various commands:

     BLOCKSIZE  The size of the block units used by several commands, most no-
                tably df(1),  du(1) and ls(1).  BLOCKSIZE 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''
                and 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 startup list of commands read by ex(1),  edit(1),  and
                vi(1).

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

     PATH       The sequence of directories, separated by colons, searched by
                csh(1),  sh(1),  system(3),  execvp(3),  etc, when looking for
                an executable file.  PATH is set to ``/usr/bin:/bin'' initial-
                ly by login(1).

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

     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 nroff(1) or plot(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.

     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 appli-
                cations use either ``/tmp'' or ``/var/tmp''. Setting this
                variable will make them use another directory.

     less you know what you are doing.

SEE ALSO

     csh(1),  ex(1),  login(1),  sh(1),  execve(2),  execle(3),  system(3),
     termcap(3),  termcap(5)

HISTORY

     The environ manual page appeared in 4.2BSD.

4.2 Berkeley Distribution       April 19, 1994                               2