1LOCALE(7) Linux Programmer's Manual LOCALE(7)
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6 locale - description of multilanguage support
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9 #include <locale.h>
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12 A locale is a set of language and cultural rules. These cover aspects
13 such as language for messages, different character sets, lexicographic
14 conventions, and so on. A program needs to be able to determine its
15 locale and act accordingly to be portable to different cultures.
16 The header <locale.h> declares data types, functions, and macros which
18 are useful in this task.
19 The functions it declares are setlocale(3) to set the current locale,
21 and localeconv(3) to get information about number formatting.
22 There are different categories for locale information a program might
24 need; they are declared as macros. Using them as the first argument to
25 the setlocale(3) function, it is possible to set one of these to the
26 desired locale:
27 LC_ADDRESS (GNU extension, since glibc 2.2)
29 Change settings that describe the formats (e.g., postal ad‐
30 dresses) used to describe locations and geography-related items.
31 Applications that need this information can use nl_langinfo(3)
32 to retrieve nonstandard elements, such as _NL_ADDRESS_COUN‐
33 TRY_NAME (country name, in the language of the locale) and
34 _NL_ADDRESS_LANG_NAME (language name, in the language of the lo‐
35 cale), which return strings such as "Deutschland" and "Deutsch"
36 (for German-language locales). (Other element names are listed
37 in <langinfo.h>.)
38 LC_COLLATE
40 This category governs the collation rules used for sorting and
41 regular expressions, including character equivalence classes and
42 multicharacter collating elements. This locale category changes
43 the behavior of the functions strcoll(3) and strxfrm(3), which
44 are used to compare strings in the local alphabet. For example,
45 the German sharp s is sorted as "ss".
46 LC_CTYPE
48 This category determines the interpretation of byte sequences as
49 characters (e.g., single versus multibyte characters), character
50 classifications (e.g., alphabetic or digit), and the behavior of
51 character classes. On glibc systems, this category also deter‐
52 mines the character transliteration rules for iconv(1) and
53 iconv(3). It changes the behavior of the character handling and
54 classification functions, such as isupper(3) and toupper(3), and
55 the multibyte character functions such as mblen(3) or wctomb(3).
56 LC_IDENTIFICATION (GNU extension, since glibc 2.2)
58 Change settings that relate to the metadata for the locale. Ap‐
59 plications that need this information can use nl_langinfo(3) to
60 retrieve nonstandard elements, such as _NL_IDENTIFICATION_TITLE
61 (title of this locale document) and _NL_IDENTIFICATION_TERRITORY
62 (geographical territory to which this locale document applies),
63 which might return strings such as "