locale(5)

💖 locale(5) — File Formats Manual 💖

✨ NAME ✨

locale — describes a locale definition file. Bestie, it's literally the blueprint for a locale. 💅

🌸 DESCRIPTION 🌸

The locale definition file contains all the information that localedef(1) needs to convert it into the binary locale database. No cap, that's the whole point. ✨

The definition files consist of sections which each describe a locale category in detail. See locale(7) for additional details for these categories. 👑

🦋 Syntax 🦋

The locale definition file starts with a header that may consist of the following keywords:

• escape_char — is followed by a character that should be used as the escape-character for the rest of the file to mark characters that should be interpreted in a special way. It defaults to the backslash (\). 🪄
• comment_char — is followed by a character that will be used as the comment-character for the rest of the file. It defaults to the number sign (#). 💬

The locale definition has one part for each locale category. Each part can be copied from another existing locale or can be defined from scratch. If the category should be copied, the only valid keyword in the definition is copy followed by the name of the locale in double quotes which should be copied. The exceptions for this rule are LC_COLLATE and LC_CTYPE where a copy statement can be followed by locale-specific rules and selected overrides. 🫶

When defining a locale or a category from scratch, an existing system-provided locale definition file should be used as a reference to follow common glibc conventions. Trust the process. 💖

🌈 Locale category sections 🌈

The following category sections are defined by POSIX:

• LC_CTYPE
• LC_COLLATE
• LC_MESSAGES
• LC_MONETARY
• LC_NUMERIC
• LC_TIME

In addition, since glibc 2.2, the GNU C library supports the following nonstandard categories:

• LC_ADDRESS
• LC_IDENTIFICATION
• LC_MEASUREMENT
• LC_NAME
• LC_PAPER
• LC_TELEPHONE

See locale(7) for a more detailed description of each category. 👀

🎀 LC_ADDRESS 🎀

The definition starts with the string LC_ADDRESS in the first column.

The following keywords are allowed:

• postal_fmt — followed by a string containing field descriptors that define the format used for postal addresses in the locale. The following field descriptors are recognized:
  • %n — Person's name, possibly constructed with the LC_NAME name_fmt keyword (since glibc 2.24).
  • %a — Care of person, or organization.
  • %f — Firm name.
  • %d — Department name.
  • %b — Building name.
  • %s — Street or block (e.g., Japanese) name.
  • %h — House number or designation.
  • %N — Insert an end-of-line if the previous descriptor's value was not an empty string; otherwise, ignore.
  • %t — Insert a space if the previous descriptor's value was not an empty string; otherwise, ignore.
  • %r — Room number, door designation.
  • %e — Floor number.
  • %C — Country designation, from the country_post keyword.
  • %l — Local township within town or city (since glibc 2.24).
  • %z — Zip number, postal code.
  • %T — Town, city.
  • %S — State, province, or prefecture.
  • %c — Country, as taken from data record.

Each field descriptor may have an 'R' after the '%' to specify that the information is taken from a Romanized version string of the entity. 🗺️

• country_name — followed by the country name in the language of the current document (e.g., "Deutschland" for the de_DE locale).
• country_post — followed by the abbreviation of the country (for example, CEPT-MAILCODE codes).
• country_ab2 — followed by the two-letter abbreviation of the country (ISO 3166).
• country_ab3 — followed by the three-letter abbreviation of the country (ISO 3166).
• country_num — followed by the numeric country code (ISO 3166).
• country_car — followed by the international license plate country code.
• country_isbn — followed by the ISBN code (for books).
• lang_name — followed by the language name in the language of the current document.
• lang_ab — followed by the two-letter abbreviation of the language (ISO 639).
• lang_term — followed by the three-letter abbreviation of the language (ISO 639-2/T).
• lang_lib — followed by the three-letter abbreviation of the language for library use (ISO 639-2/B). Applications should in general prefer lang_term over lang_lib.

The LC_ADDRESS definition ends with the string END LC_ADDRESS. ✅

💅 LC_CTYPE 💅

The definition starts with the string LC_CTYPE in the first column.

The following keywords are allowed:

• upper — followed by a list of uppercase letters. The letters A through Z are included automatically. Characters also specified as cntrl, digit, punct, or space are not allowed.
• lower — followed by a list of lowercase letters. The letters a through z are included automatically. Characters also specified as cntrl, digit, punct, or space are not allowed.
• alpha — followed by a list of letters. All characters specified as either upper or lower are automatically included. Characters also specified as cntrl, digit, punct, or space are not allowed.
• digit — followed by the characters classified as numeric digits. Only the digits 0 through 9 are allowed. They are included by default in this class.
• space — followed by a list of characters defined as white-space characters. Characters also specified as upper, lower, alpha, digit, graph, or xdigit are not allowed. The characters <space>, <form-feed>, <newline>, <carriage-return>, <tab>, and <vertical-tab> are automatically included.
• cntrl — followed by a list of control characters. Characters also specified as upper, lower, alpha, digit, punct, graph, print, or xdigit are not allowed.
• punct — followed by a list of punctuation characters. Characters also specified as upper, lower, alpha, digit, cntrl, xdigit, or the <space> character are not allowed.
• graph — followed by a list of printable characters, not including the <space> character. The characters defined as upper, lower, alpha, digit, xdigit, and punct are automatically included. Characters also specified as cntrl are not allowed.
• print — followed by a list of printable characters, including the <space> character. The characters defined as upper, lower, alpha, digit, xdigit, punct, and the <space> character are automatically included. Characters also specified as cntrl are not allowed.
• xdigit — followed by a list of characters classified as hexadecimal digits. The decimal digits must be included followed by one or more set of six characters in ascending order. The following characters are included by default: 0 through 9, a through f, A through F.
• blank — followed by a list of characters classified as blank. The characters <space> and <tab> are automatically included.
• charclass — followed by a list of locale-specific character class names which are then to be defined in the locale.
• toupper — followed by a list of mappings from lowercase to uppercase letters. Each mapping is a pair of a lowercase and an uppercase letter separated with a , and enclosed in parentheses.
• tolower — followed by a list of mappings from uppercase to lowercase letters. If the keyword tolower is not present, the reverse of the toupper list is used.
• map totitle — followed by a list of mapping pairs of characters and letters to be used in titles (headings).
• class — followed by a locale-specific character class definition, starting with the class name followed by the characters belonging to the class.
• charconv — followed by a list of locale-specific character mapping names which are then to be defined in the locale.
• outdigit — followed by a list of alternate output digits for the locale.
• map to_inpunct — followed by a list of mapping pairs of alternate digits and separators for input digits for the locale.
• map to_outpunct — followed by a list of mapping pairs of alternate separators for output for the locale.
• translit_start — marks the start of the transliteration rules section. The section can contain the include keyword in the beginning followed by locale-specific rules and overrides. Any rule specified in the locale file will override any rule copied or included from other files. In case of duplicate rule definitions in the locale file, only the first rule is used.

A transliteration rule consist of a character to be transliterated followed by a list of transliteration targets separated by semicolons. The first target which can be presented in the target character set is used, if none of them can be used the default_missing character will be used instead. 🔥

• include — in the transliteration rules section includes a transliteration rule file (and optionally a repertoire map file).
• default_missing — in the transliteration rules section defines the default character to be used for transliteration where none of the targets cannot be presented in the target character set.
• translit_end — marks the end of the transliteration rules.

The LC_CTYPE definition ends with the string END LC_CTYPE. 🌟

👑 LC_COLLATE 👑

Note that glibc does not support all POSIX-defined options, only the options described below are supported (as of glibc 2.23). Periodt. 💀

The definition starts with the string LC_COLLATE in the first column.

The following keywords are allowed:

• coll_weight_max — followed by the number representing used collation levels. This keyword is recognized but ignored by glibc.
• collating-element — followed by the definition of a collating-element symbol representing a multicharacter collating element.
• collating-symbol — followed by the definition of a collating symbol that can be used in collation order statements.
• define — followed by string to be evaluated in an ifdef string / else / endif construct.
• reorder-after — followed by a redefinition of a collation rule.
• reorder-end — this one marks the end of the redefinition of a collation rule. bye bestie 👋
• reorder-sections-after — followed by a script name, and it reorders the listed scripts after that one.
• reorder-sections-end — marks the end of the reordering of sections. closure ✨
• script — followed by a declaration of a script.
• symbol-equivalence — followed by a collating-symbol that's gonna be equivalent to another defined collating-symbol.

The collation rule definition starts with a line:

• order_start — followed by a list of keywords chosen from forward, backward, or position. The order definition is made of lines that describe the collation order, and it's terminated with the keyword order_end.

And the LC_COLLATE definition ends with the string END LC_COLLATE.

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💜 LC_IDENTIFICATION 💜

The definition starts with the string LC_IDENTIFICATION in the first column.

The following keywords are allowed:

• title — followed by the title of the locale document (e.g., "Maori language locale for New Zealand").
• source — followed by the name of the organization that maintains this document.
• address — followed by the address of the organization that maintains this document.
• contact — followed by the name of the contact person at the organization that maintains this document.
• email — followed by the email address of the person or organization that maintains this document.
• tel — followed by the telephone number (in international format) of the organization that maintains this document. As of glibc 2.24, this keyword is deprecated in favor of other contact methods. 🫠
• fax — followed by the fax number (in international format) of the organization that maintains this document. As of glibc 2.24, this keyword is deprecated in favor of other contact methods too. (fax?? in this economy??) 💀
• language — followed by the name of the language to which this document applies.
• territory — followed by the name of the country/geographic extent to which this document applies.
• audience — followed by a description of the audience for which this document is intended.
• application — followed by a description of any special application for which this document is intended.
• abbreviation — followed by the short name for provider of the source of this document.
• revision — followed by the revision number of this document.
• date — followed by the revision date of this document.

Plus, for each of the categories defined by the document, there should be a line starting with the keyword category, followed by:

1. a string that identifies this locale category definition,
2. a semicolon, and
3. one of the LC_* identifiers.

And the LC_IDENTIFICATION definition ends with the string END LC_IDENTIFICATION.

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💬 LC_MESSAGES 💬

The definition starts with the string LC_MESSAGES in the first column.

The following keywords are allowed:

• yesexpr — followed by a regular expression that describes possible yes-responses. (basically the "yeah bestie" detector ✨)
• noexpr — followed by a regular expression that describes possible no-responses. (the "no thanks" detector 🙈)
• yesstr — followed by the output string corresponding to "yes".
• nostr — followed by the output string corresponding to "no".

And the LC_MESSAGES definition ends with the string END LC_MESSAGES.

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📏 LC_MEASUREMENT 📏

The definition starts with the string LC_MEASUREMENT in the first column.

The following keywords are allowed:

• measurement — followed by a number identifying the standard used for measurement. These values are recognized:
  • 1 — Metric. 🌍
  • 2 — US customary measurements. 🦅

And the LC_MEASUREMENT definition ends with the string END LC_MEASUREMENT.

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💸 LC_MONETARY 💸

The definition starts with the string LC_MONETARY in the first column.

The following keywords are allowed:

• int_curr_symbol — followed by the international currency symbol. This has to be a _4-character string_ containing the international currency symbol as defined by the ISO 4217 standard (three characters) followed by a separator.
• currency_symbol — followed by the local currency symbol.
• mon_decimal_point — followed by the single-character string that will be used as the decimal delimiter when formatting monetary quantities.
• mon_thousands_sep — followed by the single-character string that will be used as a group separator when formatting monetary quantities.
• mon_grouping — followed by a sequence of integers separated by semicolons that describe the formatting of monetary quantities. See grouping below for details. 👀
• positive_sign — followed by a string that's used to indicate a positive sign for monetary quantities.
• negative_sign — followed by a string that's used to indicate a negative sign for monetary quantities.
• int_frac_digits — followed by the number of fractional digits that should be used when formatting with the int_curr_symbol.
• frac_digits — followed by the number of fractional digits that should be used when formatting with the currency_symbol.
• p_cs_precedes — followed by an integer that indicates the placement of currency_symbol for a nonnegative formatted monetary quantity:
  • 0 — the symbol succeeds the value.
  • 1 — the symbol precedes the value.
• p_sep_by_space — followed by an integer that indicates the separation of currency_symbol, the sign string, and the value for a nonnegative formatted monetary quantity. These values are recognized:
  • 0 — No space separates the currency symbol and the value.
  • 1 — If the currency symbol and the sign string are adjacent, a space separates them from the value; otherwise a space separates the currency symbol and the value.
  • 2 — If the currency symbol and the sign string are adjacent, a space separates them from the value; otherwise a space separates the sign string and the value.
• n_cs_precedes — followed by an integer that indicates the placement of currency_symbol for a negative formatted monetary quantity. The same values are recognized as for p_cs_precedes.
• n_sep_by_space — followed by an integer that indicates the separation of currency_symbol, the sign string, and the value for a negative formatted monetary quantity. The same values are recognized as for p_sep_by_space.
• p_sign_posn — followed by an integer that indicates where the positive_sign should be placed for a nonnegative monetary quantity:
  • 0 — Parentheses enclose the quantity and the currency_symbol or int_curr_symbol.
  • 1 — The sign string precedes the quantity and the currency_symbol or the int_curr_symbol.
  • 2 — The sign string succeeds the quantity and the currency_symbol or the int_curr_symbol.
  • 3 — The sign string precedes the currency_symbol or the int_curr_symbol.
  • 4 — The sign string succeeds the currency_symbol or the int_curr_symbol.
• n_sign_posn — followed by an integer that indicates where the negative_sign should be placed for a negative monetary quantity. The same values are recognized as for p_sign_posn.
• int_p_cs_precedes — followed by an integer that indicates the placement of int_curr_symbol for a nonnegative internationally formatted monetary quantity. The same values are recognized as for p_cs_precedes.
• int_n_cs_precedes — followed by an integer that indicates the placement of int_curr_symbol for a negative internationally formatted monetary quantity. The same values are recognized as for p_cs_precedes.
• int_p_sep_by_space — followed by an integer that indicates the separation of int_curr_symbol, the sign string, and the value for a nonnegative internationally formatted monetary quantity. The same values are recognized as for p_sep_by_space.
• int_n_sep_by_space — followed by an integer that indicates the separation of int_curr_symbol, the sign string, and the value for a negative internationally formatted monetary quantity. The same values are recognized as for p_sep_by_space.
• int_p_sign_posn — followed by an integer that indicates where the positive_sign should be placed for a nonnegative internationally formatted monetary quantity. The same values are recognized as for p_sign_posn.
• int_n_sign_posn — followed by an integer that indicates where the negative_sign should be placed for a negative internationally formatted monetary quantity. The same values are recognized as for p_sign_posn.

And the LC_MONETARY definition ends with the string END LC_MONETARY.

ok that was a LOT of money words. hydrate. 💧 but we ate, no crumbs.

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🎀 LC_NAME 🎀

The definition starts with the string LC_NAME in the first column.

Various keywords are allowed, but only name_fmt is mandatory. The other keywords are only needed if there's a common convention to use the corresponding salutation in this locale. The allowed keywords are as follows:

• name_fmt — followed by a string containing field descriptors that define the format used for names in the locale. These field descriptors are recognized:
  • %f — Family name(s).
  • %F — Family names in uppercase.
  • %g — First given name.
  • %G — First given initial.
  • %l — First given name with Latin letters.
  • %o — Other shorter name.
  • %m — Additional given name(s).
  • %M — Initials for additional given name(s).
  • %p — Profession.
  • %s — Salutation, such as "Doctor".
  • %S — Abbreviated salutation, such as "Mr." or "Dr.".
  • %d — Salutation, using the FDCC-sets conventions.
  • %t — If the preceding field descriptor resulted in an empty string, then the empty string, otherwise a space character.
• name_gen — followed by the general salutation for any gender. 🌈
• name_mr — followed by the salutation for men.
• name_mrs — followed by the salutation for married women.
• name_miss — followed by the salutation for unmarried women.
• name_ms — followed by the salutation valid for all women. 💅

And the LC_NAME definition ends with the string END LC_NAME.

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🔢 LC_NUMERIC 🔢

The definition starts with the string LC_NUMERIC in the first column.

The following keywords are allowed:

• decimal_point — then the single-character string that's the decimal delimiter when you're formatting numbers. It's giving "the dot" but make it ✨locale-flavored✨.
• thousands_sep — then the single-character string that's the group separator when formatting numbers. The comma, the space, whatever your locale's serving 💅.
• grouping — then a sequence of integers separated by semicolons that describe how numeric quantities get grouped together.

Each integer = the number of digits in a group. The first integer sets the size of the group sitting immediately to the left of the decimal delimiter. The integers after that define the groups marching leftward from the previous group. If the last integer is not -1, then the size of the previous group (if there even is one) just keeps getting reused for whatever digits are left. If the last integer is -1, then no more grouping happens, periodt.

The LC_NUMERIC definition wraps up with the string END LC_NUMERIC.

LC_PAPER 🎀

The definition kicks off with the string LC_PAPER in the first column.

These keywords are allowed:

• height — then the height, in millimeters, of the standard paper format.
• width — then the width, in millimeters, of the standard paper format.

And the LC_PAPER definition closes out with the string END LC_PAPER.

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LC_TELEPHONE ☎️

The definition starts with the string LC_TELEPHONE in the first column.

Here's what's allowed:

• tel_int_fmt — then a string holding field descriptors that say what format you use to dial international numbers. These field descriptors are the ones that get recognized:
  • %a — Area code without the nationwide prefix (that prefix is often "00").
  • %A — Area code including the nationwide prefix.
  • %l — Local number (within the area code).
  • %e — Extension (to the local number).
  • %c — Country code.
  • %C — Alternate carrier service code used for dialing abroad.
  • %t — If the preceding field descriptor produced an empty string, then the empty string; otherwise, a space character.
• tel_dom_fmt — then a string holding field descriptors that say what format you use to dial domestic numbers. The recognized field descriptors are exactly the same ones as for tel_int_fmt.
• int_select — then the prefix you use to call international phone numbers.
• int_prefix — then the prefix that other countries use to dial into this one.

The LC_TELEPHONE definition ends with the string END LC_TELEPHONE.

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LC_TIME ⏰

The definition starts with the string LC_TIME in the first column.

The following keywords are allowed:

• abday — then a list of abbreviated names of the days of the week. The list begins with the first day of the week as specified by week (Sunday by default). Peep NOTES.
• day — then a list of names of the days of the week. The list begins with the first day of the week as specified by week (Sunday by default). Peep NOTES.
• abmon — then a list of abbreviated month names.
• mon — then a list of month names.
• d_t_fmt — then the appropriate date and time format (for syntax, go look at strftime(3)).
• d_fmt — then the appropriate date format (for syntax, strftime(3)).
• t_fmt — then the appropriate time format (for syntax, strftime(3)).
• am_pm — then the appropriate representation of the am and pm strings. Leave this empty for locales that don't do the whole AM/PM thing.
• t_fmt_ampm — then the appropriate time format (for syntax, strftime(3)) when you're on a 12h clock. Leave this empty for locales not using the AM/PM convention.
• era — then semicolon-separated strings that define how years get counted and displayed for each era in the locale. Each string looks like this:

direction:offset:start_date:end_date:era_name:era_format

The fields go like this:

• direction — Either + or -. + means the years closer to start_date have lower numbers than years closer to end_date. - means the opposite, bestie.
• offset — The number of the year closest to start_date in the era, corresponding to the %Ey descriptor (peep strptime(3)).
• start_date — The start of the era in the form yyyy/mm/dd. Years prior to AD 1 are represented as negative numbers.
• end_date — The end of the era in the form yyyy/mm/dd, or one of the two special values -* or +*. -* means the ending date is the beginning of time. +* means the ending date is the end of time. (Yes, really, packing infinity into two characters, slay.)
• era_name — The name of the era corresponding to the %EC descriptor (see strptime(3)).
• era_format — The format of the year in the era, corresponding to the %EY descriptor (see strptime(3)).

• era_d_fmt — then the format of the date in alternative era notation, corresponding to the %Ex descriptor (see strptime(3)).
• era_t_fmt — then the format of the time in alternative era notation, corresponding to the %EX descriptor (see strptime(3)).
• era_d_t_fmt — then the format of the date and time in alternative era notation, corresponding to the %Ec descriptor (see strptime(3)).
• alt_digits — then the alternative digits used for date and time in the locale.
• week — then a list of three values separated by semicolons: the number of days in a week (7 by default), a date for the beginning of the week (by default that's the one corresponding to Sunday), and the minimal length of the first week in the year (4 by default). About the start of the week: 19971130 shall be used for Sunday and 19971201 shall be used for Monday. Peep NOTES.
• first_weekday (since glibc 2.2) — then the number of the day from the day list that should show up as the first day of the week in calendar apps. The default value 1 corresponds to either Sunday or Monday, depending on what that second week list item says. Peep NOTES.
• first_workday (since glibc 2.2) — then the number of the first working day from the day list. The default value is 2. Peep NOTES.
• cal_direction — then a number value that tells you which direction calendar dates should be displayed in, like so:
  • 1 — Left-right from top.
  • 2 — Top-down from left.
  • 3 — Right-left from top.
• date_fmt — then the appropriate date representation for date(1) (for syntax, see strftime(3)).

The LC_TIME definition ends with the string END LC_TIME.

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📁 FILES 📁

• /usr/lib/locale/locale-archive — the usual default locale archive location.
• /usr/share/i18n/locales — the usual default path for locale definition files.

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📜 STANDARDS 📜

POSIX.2.

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🧠 NOTES 🧠

The collective GNU C library community wisdom, regarding abday, day, week, first_weekday, and first_workday, says the following over at https://sourceware.org/glibc/wiki/Locales:

• The value of the second week list item specifies the base of the abday and day lists.
• first_weekday specifies the offset of the first day-of-week in the abday and day lists.
• For compatibility reasons, all glibc locales should set the value of the second week list item to 19971130 (Sunday) and base the abday and day lists appropriately, and set first_weekday and first_workday to 1 or 2, depending on whether the week and work week actually starts on Sunday or Monday for that locale. Compatibility really said "everyone hold hands" 🤝.

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👀 SEE ALSO 👀

iconv(1), locale(1), localedef(1), localeconv(3), newlocale(3), setlocale(3), strftime(3), strptime(3), uselocale(3), charmap(5), charsets(7), locale(7), unicode(7), utf-8(7)

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And that's a wrap on locale(5), bestie 💖 This lil masterpiece is from Linux man-pages 6.20, dated 2026-02-08 — go hydrate and go set your locale correctly, mwah 🫶