конкретная информация (specific information)
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
locale — get locale-specific information
Синопсис (Synopsis)
locale [-a|-m]
locale [-ck] name...
Описание (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.
Параметры (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.
Операнды (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.
Стандартный ввод (Stdin)
Not used.
Входные файлы (Input files)
None.
Переменные окружения (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.
Асинхронные события (Asynchronous events)
Default.
Стандартный вывод (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.
Стандартный вывод сообщений (Stderr)
The standard error shall be used only for diagnostic messages.
Выходные файлы (Output files)
None.
Расширенное описание (Extended description)
None.
Статус выхода (Exit)
The following exit values shall be returned:
0 All the requested information was found and output
successfully.
>0 An error occurred.
Последствия ошибок (Consequences of errors)
Default.
The following sections are informative.
Использование в приложениях (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).
Примеры (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
Обоснование (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.
Будущие направления (Future directions)
None.
Смотри также (See also)
localedef(1p)
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
