The following environment variables shall affect the execution of
ls:
COLUMNS Determine the user's preferred column position width
for writing multiple text-column output. If this
variable contains a string representing a decimal
integer, the ls utility shall calculate how many
pathname text columns to write (see -C) based on the
width provided. If COLUMNS is not set or invalid, an
implementation-defined number of column positions shall
be assumed, based on the implementation's knowledge of
the output device. The column width chosen to write the
names of files in any given directory shall be
constant. Filenames shall not be truncated to fit into
the multiple text-column output.
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 character collation
information in determining the pathname collation
sequence.
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 which characters are
defined as printable (character class print).
LC_MESSAGES
Determine the locale that should be used to affect the
format and contents of diagnostic messages written to
standard error.
LC_TIME Determine the format and contents for date and time
strings written by ls.
NLSPATH Determine the location of message catalogs for the
processing of LC_MESSAGES.
TZ Determine the timezone for date and time strings
written by ls. If TZ is unset or null, an unspecified
default timezone shall be used.
