LOCALE(1)                  POSIX Programmer's Manual                 LOCALE(1)



PROLOG
       This manual page is part of the POSIX Programmer's Manual.  The OS
       implementation of this interface may differ (consult the corresponding
       OS manual page for details of OS behavior), or the interface may not be
       implemented on OS.

NAME
       locale -- get locale-specific information

SYNOPSIS
       locale [[-a|-m]]

       locale [[-ck]] name...

DESCRIPTION
       The locale utility shall write information about the current locale
       environment, or all public locales, to the standard output. For the
       purposes of this section, a public locale is one provided by the
       implementation that is accessible to the application.

       When locale is invoked without any arguments, it shall summarize the
       current locale environment for each locale category as determined by
       the settings of the environment variables defined in the Base
       Definitions volume of POSIX.1-2017, Chapter _7, Locale.

       When invoked with operands, it shall write values that have been
       assigned to the keywords in the locale categories, as follows:

        *  Specifying a keyword name shall select the named keyword and the
           category containing that keyword.

        *  Specifying a category name shall select the named category and all
           keywords in that category.

OPTIONS
       The locale utility shall conform to the Base Definitions volume of
       POSIX.1-2017, Section 12.2, Utility Syntax Guidelines.

       The following options shall be supported:

       -a        Write information about all available public locales. The
                 available locales shall include POSIX, representing the POSIX
                 locale. The manner in which the implementation determines
                 what other locales are available is implementation-defined.

       -c        Write the names of selected locale categories; see the STDOUT
                 section.  The -c option increases readability when more than
                 one category is selected (for example, via more than one
                 keyword name or via a category name).  It is valid both with
                 and without the -k option.

       -k        Write the names and values of selected keywords. The
                 implementation may omit values for some keywords; see the
                 OPERANDS section.

       -m        Write names of available charmaps; see the Base Definitions
                 volume of POSIX.1-2017, Section 6.1, Portable Character Set.

OPERANDS
       The following operand shall be supported:

       name      The name of a locale category as defined in the Base
                 Definitions volume of POSIX.1-2017, Chapter _7, Locale, the
                 name of a keyword in a locale category, or the reserved name
                 charmap.  The named category or keyword shall be selected for
                 output. If a single name represents both a locale category
                 name and a keyword name in the current locale, the results
                 are unspecified. Otherwise, both category and keyword names
                 can be specified as name operands, in any sequence. It is
                 implementation-defined whether any keyword values are written
                 for the categories LC__CTYPE and LC__COLLATE.

STDIN
       Not used.

INPUT FILES
       None.

ENVIRONMENT VARIABLES
       The following environment variables shall affect the execution of
       locale:

       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__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).

       LC__MESSAGES
                 Determine the locale that should be used to affect the format
                 and contents of diagnostic messages written to standard
                 error.

       NLSPATH   Determine the location of message catalogs for the processing
                 of LC__MESSAGES.

       The application shall ensure that the LANG, LC___*, and NLSPATH
       environment variables specify the current locale environment to be
       written out; they shall be used if the -a option is not specified.

ASYNCHRONOUS EVENTS
       Default.

STDOUT
       The LANG variable shall be written first using the format:


           "LANG=%s\n", <value>

       If LANG is not set or is an empty string, the value is the empty
       string.

       If locale is invoked without any options or operands, the names and
       values of the LC___* environment variables described in this volume of
       POSIX.1-2017 shall be written to the standard output, one variable per
       line, and each line using the following format. Only those variables
       set in the environment and not overridden by LC__ALL shall be written
       using this format:


           "%s=%s\n", <variable__name>, <value>

       The names of those LC___* variables associated with locale categories
       defined in this volume of POSIX.1-2017 that are not set in the
       environment or are overridden by LC__ALL shall be written in the
       following format:


           "%s=\"%s\"\n", <variable__name>, <implied value>

       The <implied value> shall be the name of the locale that has been
       selected for that category by the implementation, based on the values
       in LANG and LC__ALL, as described in the Base Definitions volume of
       POSIX.1-2017, Chapter _8, Environment Variables.

       The <value> and <implied value> shown above shall be properly quoted
       for possible later reentry to the shell. The <value> shall not be
       quoted using double-quotes (so that it can be distinguished by the user
       from the <implied value> case, which always requires double-quotes).

       The LC__ALL variable shall be written last, using the first format shown
       above. If it is not set, it shall be written as:


           "LC_ALL=\n"

       If any arguments are specified:

        1. If the -a option is specified, the names of all the public locales
           shall be written, each in the following format:


               "%s\n", <locale name>

        2. If the -c option is specified, the names of all selected categories
           shall be written, each in the following format:


               "%s\n", <category name>

           If keywords are also selected for writing (see following items),
           the category name output shall precede the keyword output for that
           category.

           If the -c option is not specified, the names of the categories
           shall not be written; only the keywords, as selected by the <name>
           operand, shall be written.

        3. If the -k option is specified, the names and values of selected
           keywords shall be written. If a value is non-numeric and is not a
           compound keyword value, it shall be written in the following
           format:


               "%s=\"%s\"\n", <keyword name>, <keyword value>

           If a value is a non-numeric compound keyword value, it shall either
           be written in the format:


               "%s=\"%s\"\n", <keyword name>, <keyword value>

           where the <keyword value> is a single string of values separated by
           <semicolon> characters, or it shall be written in the format:


               "%s=%s\n", <keyword name>, <keyword value>

           where the <keyword value> is encoded as a set of strings, each
           enclosed in double-quotation-marks, separated by <semicolon>
           characters.

           If the keyword was charmap, the name of the charmap (if any) that
           was specified via the localedef -f option when the locale was
           created shall be written, with the word charmap as <keyword name>.

           If a value is numeric, it shall be written in one of the following
           formats:


               "%s=%d\n", <keyword name>, <keyword value>

               "%s=%c%o\n", <keyword name>, <escape character>, <keyword value>

               "%s=%cx%x\n", <keyword name>, <escape character>, <keyword value>

           where the <escape character> is that identified by the escape_char
           keyword in the current locale; see the Base Definitions volume of
           POSIX.1-2017, Section 7.3, Locale Definition.

           Compound keyword values (list entries) shall be separated in the
           output by <semicolon> characters. When included in keyword values,
           the <semicolon>, <backslash>, double-quote, and any control
           character shall be preceded (escaped) with the escape character.

        4. If the -k option is not specified, selected keyword values shall be
           written, each in the following format:


               "%s\n", <keyword value>

           If the keyword was charmap, the name of the charmap (if any) that
           was specified via the localedef -f option when the locale was
           created shall be written.

        5. If the -m option is specified, then a list of all available
           charmaps shall be written, each in the format:


               "%s\n", <charmap>

           where <charmap> is in a format suitable for use as the option-
           argument to the localedef -f option.

STDERR
       The standard error shall be used only for diagnostic messages.

OUTPUT FILES
       None.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       The following exit values shall be returned:

        0    All the requested information was found and output successfully.

       >0    An error occurred.

CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       If the LANG environment variable is not set or set to an empty value,
       or one of the LC___* environment variables is set to an unrecognized
       value, the actual locales assumed (if any) are implementation-defined
       as described in the Base Definitions volume of POSIX.1-2017, Chapter _8,
       Environment Variables.

       Implementations are not required to write out the actual values for
       keywords in the categories LC__CTYPE and LC__COLLATE; however, they must
       write out the categories (allowing an application to determine, for
       example, which character classes are available).

EXAMPLES
       In the following examples, the assumption is that locale environment
       variables are set as follows:


           LANG=locale_x
           LC_COLLATE=locale_y

       The command locale would result in the following output:


           LANG=locale_x
           LC_CTYPE="locale_x"
           LC_COLLATE=locale_y
           LC_TIME="locale_x"
           LC_NUMERIC="locale_x"
           LC_MONETARY="locale_x"
           LC_MESSAGES="locale_x"
           LC_ALL=

       The order of presentation of the categories is not specified by this
       volume of POSIX.1-2017.

       The command:


           LC_ALL=POSIX locale -ck decimal_point

       would produce:


           LC_NUMERIC
           decimal_point="."

       The following command shows an application of locale to determine
       whether a user-supplied response is affirmative:


           printf 'Prompt for response: '
           read response
           if printf "%s\n$response" | grep -- -Eq "$(locale yesexpr)"
           then
               affirmative processing goes here
           else
               non-affirmative processing goes here
           fi

RATIONALE
       The output for categories LC__CTYPE and LC__COLLATE has been made
       implementation-defined because there is a questionable value in having
       a shell script receive an entire array of characters.  It is also
       difficult to return a logical collation description, short of returning
       a complete localedef source.

       The -m option was included to allow applications to query for the
       existence of charmaps.  The output is a list of the charmaps
       (implementation-supplied and user-supplied, if any) on the system.

       The -c option was included for readability when more than one category
       is selected (for example, via more than one keyword name or via a
       category name). It is valid both with and without the -k option.

       The charmap keyword, which returns the name of the charmap (if any)
       that was used when the current locale was created, was included to
       allow applications needing the information to retrieve it.

       According to the Base Definitions volume of POSIX.1-2017, Section 6.1,
       Portable Character Set, the standard requires that all supported
       locales must have the same encoding for <period> and <slash>, because
       these two characters are used within the locale-independent pathname
       resolution sequence. Therefore, it would be an error if locale -a
       listed both ASCII and EBCDIC-based locales, since those two encodings
       do not share the same representation for either <period> or <slash>.
       Any system that supports both environments would be expected to provide
       two POSIX locales, one in either codeset, where only the locales
       appropriate to the current environment can be visible at a time. In an
       XSI-compliant implementation, the dd utility is the only portable means
       for performing conversions between the two character sets.

FUTURE DIRECTIONS
       None.

SEE ALSO
       localedef

       The Base Definitions volume of POSIX.1-2017, Section 6.1, Portable
       Character Set, Chapter _7, Locale, Chapter _8, Environment Variables,
       Section 12.2, Utility Syntax Guidelines

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  In the event of any discrepancy between this version and the
       original IEEE and The Open Group Standard, the original IEEE and The
       Open Group Standard is the referee document. The original Standard can
       be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                            LOCALE(1)
