ENVIRON(7) | Miscellaneous Information Manual | ENVIRON(7)

# NAME

`environ` — user 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 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, /usr/local/bin, and /usr/local/sbin 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=America/Los_Angeles 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).

# SEE ALSO

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)

# HISTORY

An `environ` manual page appeared in Version 7 AT&T UNIX.

February 9, 2020 | Debian