The size of the block units used by several commands, most notably 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.
COLUMNS
The users preferred width in column positions for the terminal. Utilities such as ls(1) and who(1) use this to format output into columns. If unset or empty, utilities will use an ioctl(2) call to ask the terminal driver for the width.
EDITOR
Default editor name.
EXINIT
A startup list of commands read by ex(1) and vi(1).
HOME
A users login directory, set by login(1) from the password file passwd(5).
LANG
This variable configures all programs which use setlocale(3) to use the specified locale unless the LC_* variables are set.
LC_ALL
Overrides the values of LC_COLLATE, LC_CTYPE, LC_MESSAGES, LC_MONETARY, LC_NUMERIC, LC_TIME and LANG.
LC_COLLATE
Locale to be used for ordering of strings.
LC_CTYPE
Locale to be used for character classification (letter, space, digit, etc.) and for interpreting byte sequences as multibyte characters.
LC_MESSAGES
Locale to be used for diagnostic messages.
LC_MONETARY
Locale to be used for interpreting monetary input and formatting output.
LC_NUMERIC
Locale to be used for interpreting numeric input and formatting output.
LC_TIME
Locale to be used for interpreting dates input and for formatting output.
MAIL
The location of the users mailbox instead of the default in /var/mail, used by mail(1), sh(1), and many other mailclients.
NLSPATH
List of directories to be searched for the message catalog referred to by LC_MESSAGES. See catopen(3).
PAGER
Default paginator program. The program specified by this variable is used by mail(1), man(1), ftp(1), etc, to display information which is longer than the current display.
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 initially by login(1).
PRINTER
The name of the default printer to be used by lpr(1), lpq(1), and lprm(1).
PWD
The current directory pathname.
SHELL
The full pathname of the users 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, and termcap(5).
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 timezone to use when displaying dates. The normal format is a pathname relative to "/usr/share/zoneinfo". For example, the command "env TZ=America/Los_Angeles date" displays the current time in California. See tzset(3) for more information.
USER
The login name of the user.
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), set(1) or printenv(1) in sh(1) and env(1), printenv(1) or the printenv built-in command in csh(1).