ENVIRON(5)                                             ENVIRON(5)

          environ - user environment

          extern char **environ;

          An array of strings called the `environment' is made avail-
          able by exec(2) 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, 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(1) 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 terminal
               capabilities.  See term(7) for a list of terminal

          Further names may be placed in the environment by the export
          command and `name=value' arguments in sh(1), or by exec(2).
          It is unwise to conflict with certain Shell variables that
          are frequently exported by `.profile' files: MAIL, PS1, PS2,

          exec(2), sh(1), term(7), login(1)