GNU/Linux |
CentOS 4.8 |
i386 |
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locale(7) |
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locale − Description of multi-language support
#include <locale.h>
A locale is a set of language and cultural rules. These cover aspects such as language for messages, different character sets, lexigraphic conventions, etc. A program needs to be able to determine its locale and act accordingly to be portable to different cultures.
The header <locale.h> declares data types, functions and macros which are useful in this task.
The functions it declares are setlocale() to set the current locale, and localeconv() to get information about number formatting.
There are
different categories for local information a program might
need; they are declared as macros. Using them as the first
argument to the setlocale() function, it is possible
to set one of these to the desired locale:
LC_COLLATE
This is used to change the behaviour of the functions strcoll() and strxfrm(), which are used to compare strings in the local alphabet. For example, the German sharp s is sorted as "ss".
LC_CTYPE
This changes the behaviour of the character handling and classification functions, such as isupper() and toupper(), and the multi−byte character functions such as mblen() or wctomb().
LC_MONETARY
changes the information returned by localeconv() which describes the way numbers are usually printed, with details such as decimal point versus decimal comma. This information is internally used by the function strfmon().
LC_MESSAGES
changes the language messages are displayed in and how an affirmative or negative answer looks like. The GNU C-library contains the gettext(), ngettext(), and rpmatch() functions to ease the use of these information. The GNU gettext family of functions also obey the environment variable LANGUAGE.
LC_NUMERIC
changes the information used by the printf() and scanf() family of functions, when they are advised to use the locale-settings. This information can also be read with the localeconv() function.
LC_TIME
changes the behaviour of the strftime() function to display the current time in a locally acceptable form; for example, most of Europe uses a 24−hour clock vs. the US’ 12−hour clock.
LC_ALL |
All of the above. |
If the second argument to setlocale() is empty string, "", for the default locale, it is determined using the following steps:
1. |
If there is a non-null environment variable LC_ALL, the value of LC_ALL is used. | ||
2. |
If an environment variable with the same name as one of the categories above exists and is non-null, its value is used for that category. | ||
3. |
If there is a non-null environment variable LANG, the value of LANG is used. |
Values about
local numeric formatting is made available in a struct
lconv returned by the localeconv() function,
which has the following declaration:
struct lconv
{
/* Numeric (non-monetary) information. */
/* Decimal point character. */ | |||||
/* Thousands separator. */ |
/* Each element is the number
of digits in each group;
elements with higher indices are farther left.
An element with value CHAR_MAX means that no further
grouping is done.
An element with value 0 means that the previous element is
used
for all groups farther left. */
char *grouping;
/* Monetary information. */
/* First three
chars are a currency symbol from ISO 4217.
Fourth char is the separator. Fifth char is ’ ’.
*/
char *int_curr_symbol;
/* Local currency symbol. */ |
/* Decimal point character. */ | |||||
/* Thousands separator. */ | ||||||
/* Like ’grouping’ element (above). */ | ||||||
/* Sign for positive values. */ | ||||||
/* Sign for negative values. */ | ||||||
/* Int’l fractional digits. */ | ||||||
/* Local fractional digits. */ |
/* 1 if currency_symbol
precedes a positive value, 0 if succeeds. */
char p_cs_precedes;
/* 1 if a space separates currency_symbol from a positive
value. */
char p_sep_by_space;
/* 1 if currency_symbol precedes a negative value, 0 if
succeeds. */
char n_cs_precedes;
/* 1 if a space separates currency_symbol from a negative
value. */
char n_sep_by_space;
/* Positive and negative sign positions:
0 Parentheses surround the quantity and currency_symbol.
1 The sign string precedes the quantity and currency_symbol.
2 The sign string succeeds the quantity and currency_symbol.
3 The sign string immediately precedes the currency_symbol.
4 The sign string immediately succeeds the currency_symbol.
*/
char p_sign_posn;
char n_sign_posn;
};
POSIX.1
The GNU gettext functions are specified in LI18NUX2000.
setlocale(3), localeconv(3), locale(1), localedef(1), nl_langinfo(3), gettext(3), ngettext(3), rpmatch(3), strfmon(3), strcoll(3), strxfrm(3), strftime(3)
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locale(7) | ![]() |