The following environment variables shall affect the execution of
cp:
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 used in the extended regular expression
defined for the yesexpr locale keyword in the
LC_MESSAGES category.
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) and the
behavior of character classes used in the extended
regular expression defined for the yesexpr locale
keyword in the LC_MESSAGES category.
LC_MESSAGES
Determine the locale used to process affirmative
responses, and the locale used to affect the format and
contents of diagnostic messages and prompts written to
standard error.
NLSPATH Determine the location of message catalogs for the
processing of LC_MESSAGES.
