environ - User environment
extern char **environ;
An array of strings called the environment is made available by the
execve() function when a process begins. By convention these strings have
the form name=value. The following names are used by various commands:
A startup list of commands read by ex, edit, and vi.
A user's login directory, set by login from the password file passwd.
The sequence of directories, separated by colons, searched by csh, sh,
system, execvp, etc, when looking for an executable file. PATH is set
to :/usr/ucb:/bin:/usr/bin initially by login.
The name of the default printer to be used by lpr, lpq, and lprm.
The full pathname of the user's login shell.
The kind of terminal for which output is to be prepared. This informa-
tion is used by commands, such as nroff which may exploit special ter-
minal capabilities. ž .\" See /usr/share/misc/termcap for a list of
terminal types. .\"from TP " .\" Bold under TP !" -->
The string describing the terminal in the TERM environment variable,
or, if it begins with a / (slash), the name of the termcap file. See
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
The login name of the user.
Further names may be placed in the environment by the export command and
name=value arguments in sh, or by the setenv command if you use csh. It is
unwise to change certain sh variables that are frequently exported by .pro-
file files, such as MAIL, PS1, PS2, and IFS.
Functions: exec(2), system(3)
Commands: csh(1), ex(1), login(1), sh(1)