environ
—
user environment
extern char **environ;
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
variables are recognized by various commands:
BLOCKSIZE
- The size of the block units used by several commands, most notably
df(1),
du(1), and
ls(1). 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’, or 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 list of startup commands read by
ex(1) and
vi(1).
HOME
- The user's login directory, set by
login(1) from the password
file passwd(5).
LOGNAME
- The login name of the user.
PATH
- The sequence of directories, separated by colons, searched by
csh(1),
sh(1),
ksh(1),
system(3),
execvp(3), etc. when
looking for an executable file. Initially set to the value of
_PATH_DEFPATH
by
login(1), traditionally
/usr/bin:/bin, but expanded to include
/usr/sbin, /sbin,
/usr/X11R6/bin, and
/usr/local/bin in
OpenBSD.
PRINTER
- The name of the default printer to be used by
lpq(1),
lpr(1), and
lprm(1).
PWD
- The current working directory.
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
mandoc(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(3).
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 applications use
either /tmp or /var/tmp.
Setting this variable will make them use another directory.
TZ
- The time zone to use when displaying dates. The normal format is a
pathname relative to /usr/share/zoneinfo. For
example, the command
env TZ=US/Pacific date
displays the current time in California. See
tzset(3) for more
information.
USER
- Deprecated synonym of
LOGNAME
(for backwards
compatibility).
Further names may be placed in the environment by the
export
command and
name=value arguments in
sh(1), or by the
setenv
command if you use
csh(1). It is unwise to change
certain sh(1) variables that are
frequently exported by .profile files, such as
MAIL
, PS1
,
PS2
, and IFS
, unless you
know what you are doing.
The current environment variables can be printed with
env(1) or
printenv(1).
csh(1),
env(1),
ex(1),
login(1),
printenv(1),
sh(1),
execve(2),
execle(3),
getenv(3),
system(3),
termcap(3),
tzset(3),
termcap(5)
The
environ
manual page appeared in
4.2BSD.