ENVIRON(7)

NAME
environ - user process environment

SYNOPSIS
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:

AUDIOCTLDEVICE
    The name of the audio control device to be used by audioctl(1), audioplay(1) and audiorecord(1).

AUDIODEVICE
    The name of the audio device to be used by audioplay(1) and audiorecord(1).

BLOCKSIZE
    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.

EXINIT
    A startup list of commands read by ex(1) and vi(1).

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

LANG
    Default for all NLS categories. Only used if LC_ALL or the environment variable for a particular NLS category is not provided (LC_COLLATE, LC_CTYPE, LC_MESSAGES, LC_MONETARY, LC_NUMERIC, or LC_TIME).

LC_ALL
    Override for all NLS categories. If set, overrides the values of LC_COLLATE, LC_CTYPE, LC_MESSAGES, LC_MONETARY, LC_NUMERIC, and LC_TIME.

LC_COLLATE
    NLS string-collation order information.

LC_CTYPE
    NLS character classification, case conversion, and other character attributes.

LC_MESSAGES
    NLS format for affirmative and negative responses.

LC_MONETARY
    NLS rules and symbols for formatting monetary numeric information.

LC_NUMERIC
    NLS rules and symbols for formatting nonmonetary numeric information.

LC_TIME
    NLS rules and symbols for formatting time and date information.

LIBC_DIAGASSERT
    Control how the _DIAGASSERT() macro (from <assert.h>) behaves once the assertion is raised. Refer to _DIAGASSERT(3) for more information.

LOGNAME
    The login name of the user.

MALLOC_OPTIONS
    Control the behaviour of the malloc() function. Refer to malloc(3) for more information.

MIXERDEVICE
    The name of the audio mixer device to be used by mixerctl(1).

PAGER
    The program used for paginating the output of several commands such as man(1). If null or not set, the standard pagination program more(1) will be used.

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:/usr/pkg/bin:/usr/local/bin” initially by login(1).

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

RCMD_CMD
    When using the rcmd(3) function, this variable is used as the program to run instead of rcmd(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) 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:/usr/share/misc/termcap”. TERMPATH is ignored if TERMCAP contains a full pathname.

TIMEFORMAT
    A strftime(3) format string that may be used by programs such as dump(8) for formatting timestamps.

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=US/Pacific date displays the current time in California. See tzset(3) for more information.

USER
    The login name of the user. It is recommended that portable applications use LOGNAME instead.

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.

SEE ALSO
audioctl(1), audioplay(1), audiorecord(1), csh(1), ex(1), login(1), man(1), more(1), sh(1), execve(2), _DIAGASSERT(3), execle(3), malloc(3), rcmd(3), system(3), termcap(3), audio(4), termcap(5), nls(7), dump(8)

HISTORY
The environ manual page appeared in 4.2BSD.