The following environment variables shall affect the execution of
ex:
COLUMNS Override the system-selected horizontal screen size.
See the Base Definitions volume of POSIX.1‐2017,
Chapter 8, Environment Variables for valid values and
results when it is unset or null.
EXINIT Determine a list of ex commands that are executed on
editor start-up. See the EXTENDED DESCRIPTION section
for more details of the initialization phase.
HOME Determine a pathname of a directory that shall be
searched for an editor start-up file named .exrc; see
the EXTENDED DESCRIPTION section.
LANG Provide a default value for the internationalization
variables that are unset or null. (See the Base
Definitions volume of POSIX.1‐2017, Section 8.2,
Internationalization Variables for the precedence of
internationalization variables used to determine the
values of locale categories.)
LC_ALL If set to a non-empty string value, override the values
of all the other internationalization variables.
LC_COLLATE
Determine the locale for the behavior of ranges,
equivalence classes, and multi-character collating
elements within regular expressions.
LC_CTYPE Determine the locale for the interpretation of
sequences of bytes of text data as characters (for
example, single-byte as opposed to multi-byte
characters in arguments and input files), the behavior
of character classes within regular expressions, the
classification of characters as uppercase or lowercase
letters, the case conversion of letters, and the
detection of word boundaries.
LC_MESSAGES
Determine the locale that should be used to affect the
format and contents of diagnostic messages written to
standard error.
LINES Override the system-selected vertical screen size, used
as the number of lines in a screenful and the vertical
screen size in visual mode. See the Base Definitions
volume of POSIX.1‐2017, Chapter 8, Environment
Variables for valid values and results when it is unset
or null.
NLSPATH Determine the location of message catalogs for the
processing of LC_MESSAGES.
PATH Determine the search path for the shell command
specified in the ex editor commands !, shell, read, and
write, and the open and visual mode command !; see the
description of command search and execution in Section
2.9.1.1, Command Search and Execution.
SHELL Determine the preferred command line interpreter for
use as the default value of the shell edit option.
TERM Determine the name of the terminal type. If this
variable is unset or null, an unspecified default
terminal type shall be used.
