The following environment variables shall affect the execution of
awk:
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 and in comparisons
of string values.
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
identification of characters as letters, and the
mapping of uppercase and lowercase characters for the
toupper and tolower functions.
LC_MESSAGES
Determine the locale that should be used to affect the
format and contents of diagnostic messages written to
standard error.
LC_NUMERIC
Determine the radix character used when interpreting
numeric input, performing conversions between numeric
and string values, and formatting numeric output.
Regardless of locale, the <period> character (the
decimal-point character of the POSIX locale) is the
decimal-point character recognized in processing awk
programs (including assignments in command line
arguments).
NLSPATH Determine the location of message catalogs for the
processing of LC_MESSAGES.
PATH Determine the search path when looking for commands
executed by system(expr), or input and output pipes;
see the Base Definitions volume of POSIX.1‐2017,
Chapter 8, Environment Variables.
In addition, all environment variables shall be visible via the
awk variable ENVIRON.
