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SETLOCALE(3)               Library Functions Manual               SETLOCALE(3)

     setlocale, localeconv - natural language formatting for C

     Standard C Library (libc, -lc)

     #include <locale.h>

     char *
     setlocale(int category, const char *locale);

     struct lconv *

     The setlocale() function sets the C library's notion of natural language
     formatting style for particular sets of routines.  Each such style is
     called a `locale' and is invoked using an appropriate name passed as a C
     string.  The localeconv() routine returns the current locale's parameters
     for formatting numbers.

     The setlocale() function recognizes several categories of routines.
     These are the categories and the sets of routines they select:

     LC_ALL       Set the entire locale generically.

     LC_COLLATE   Set a locale for string collation routines.  This controls
                  alphabetic ordering in strcoll() and strxfrm().

     LC_CTYPE     Set a locale for the ctype(3) functions.  This controls
                  recognition of upper and lower case, alphabetic or non-
                  alphabetic characters, and so on.

     LC_MESSAGES  Set a locale for message catalogs.  This controls the
                  selection of message catalogs by the catgets(3) and
                  gettext(3) families of functions.

     LC_MONETARY  Set a locale for formatting monetary values; this affects
                  the localeconv() function.

     LC_NUMERIC   Set a locale for formatting numbers.  This controls the
                  formatting of decimal points in input and output of floating
                  point numbers in functions such as printf() and scanf(), as
                  well as values returned by localeconv().

     LC_TIME      Set a locale for formatting dates and times using the
                  strftime() function.

     Only three locales are defined by default, the empty string "" which
     denotes the native environment, and the "C" and "POSIX" locales, which
     denote the C language environment.  A locale argument of NULL causes
     setlocale() to return the current locale.  By default, C programs start
     in the "C" locale.  The format of the locale string is described in

     The only function in the library that sets the locale is setlocale(); the
     locale is never changed as a side effect of some other routine.

     Changing the setting of LC_MESSAGES has no effect on catalogs that have
     already been opened by catopen(3).

     The localeconv() function returns a pointer to a structure which provides
     parameters for formatting numbers, especially currency values:

           struct lconv {
                   char    *decimal_point;
                   char    *thousands_sep;
                   char    *grouping;
                   char    *int_curr_symbol;
                   char    *currency_symbol;
                   char    *mon_decimal_point;
                   char    *mon_thousands_sep;
                   char    *mon_grouping;
                   char    *positive_sign;
                   char    *negative_sign;
                   char    int_frac_digits;
                   char    frac_digits;
                   char    p_cs_precedes;
                   char    p_sep_by_space;
                   char    n_cs_precedes;
                   char    n_sep_by_space;
                   char    p_sign_posn;
                   char    n_sign_posn;
                   char    int_p_cs_precedes;
                   char    int_n_cs_precedes;
                   char    int_p_sep_by_space;
                   char    int_n_sep_by_space;
                   char    int_p_sign_posn;
                   char    int_n_sign_posn;

     The individual fields have the following meanings:

     decimal_point       The decimal point character, except for monetary

     thousands_sep       The separator between groups of digits before the
                         decimal point, except for monetary values.

     grouping            The sizes of the groups of digits, except for
                         monetary values.  This is a pointer to a vector of
                         integers, each of size char, representing group size
                         from low order digit groups to high order (right to
                         left).  The list may be terminated with 0 or
                         CHAR_MAX.  If the list is terminated with 0, the last
                         group size before the 0 is repeated to account for
                         all the digits.  If the list is terminated with
                         CHAR_MAX, no more grouping is performed.

     int_curr_symbol     The standardized (ISO 4217:1995) international
                         currency symbol.

     currency_symbol     The local currency symbol.

     mon_decimal_point   The decimal point character for monetary values.

     mon_thousands_sep   The separator for digit groups in monetary values.

     mon_grouping        Like grouping but for monetary values.

     positive_sign       The character used to denote nonnegative monetary
                         values, usually the empty string.

     negative_sign       The character used to denote negative monetary
                         values, usually a minus sign.

     int_frac_digits     The number of digits after the decimal point in an
                         internationally formatted monetary value.

     frac_digits         The number of digits after the decimal point in an
                         locally formatted monetary value.

     p_cs_precedes       1 if the currency symbol precedes the monetary value
                         for nonnegative values, 0 if it follows.

     p_sep_by_space      1 if a space is inserted between the currency symbol
                         and the monetary value for nonnegative values, 0

     n_cs_precedes       Like p_cs_precedes but for negative values.

     n_sep_by_space      Like p_sep_by_space but for negative values.

     p_sign_posn         The location of the positive_sign with respect to a
                         nonnegative quantity and the currency_symbol.

     n_sign_posn         Like p_sign_posn but for negative currency values.

     int_p_cs_precedes   1 if the currency symbol precedes the internationally
                         formatted monetary value for nonnegative values, 0 if
                         it follows.

     int_n_cs_precedes   Like int_p_cs_precedes but for negative values.

     int_p_sep_by_space  1 if a space is inserted between the currency symbol
                         and the internationally formatted monetary value for
                         nonnegative values, 0 otherwise.

     int_n_sep_by_space  Like int_p_sep_by_space but for negative values.

     int_p_sign_posn     The location of the positive_sign with respect to a
                         nonnegative quantity and the currency_symbol, for
                         internationally formatted nonnegative monetary

     int_n_sign_posn     Like int_p_sign_posn but for negative values.

     The positional parameters in p_sign_posn, n_sign_posn, int_p_sign_posn
     and int_n_sign_posn are encoded as follows:
     0    Parentheses around the entire string.
     1    Before the string.
     2    After the string.
     3    Just before currency_symbol.
     4    Just after currency_symbol.

     Unless mentioned above, an empty string as a value for a field indicates
     a zero length result or a value that is not in the current locale.  A
     CHAR_MAX result similarly denotes an unavailable value.

     The setlocale() function returns NULL and fails to change the locale if
     the given combination of category and locale makes no sense.  The
     localeconv() function returns a pointer to a static object which may be
     altered by later calls to setlocale() or localeconv().

     The following code illustrates how a program can initialize the
     international environment for one language, while selectively modifying
     the program's locale such that regular expressions and string operations
     can be applied to text recorded in a different language:

             setlocale(LC_ALL, "de");
             setlocale(LC_COLLATE, "fr");

     When a process is started, its current locale is set to the C or POSIX
     locale.  An internationalized program that depends on locale data not
     defined in the C or POSIX locale must invoke the setlocale subroutine in
     the following manner before using any of the locale-specific information:

             setlocale(LC_ALL, "");

     The use of multibyte locales requires shared libraries located in

     catopen(3), gettext(3), nl_langinfo(3), nls(7)

     The setlocale() and localeconv() functions conform to ANSI X3.159-1989
     ("ANSI C89") and ISO/IEC 9899:1990 ("ISO C90").

     The int_p_cs_precedes, int_n_cs_precedes, int_p_sep_by_space,
     int_n_sep_by_space, int_p_sign_posn and int_n_sign_posn members of struct
     lconv were introduced in ISO/IEC 9899:1999 ("ISO C99").

     The setlocale() and localeconv() functions first appeared in 4.4BSD.

     The current implementation supports only the "C" and "POSIX" locales for
     all but the LC_CTYPE locale.

     In spite of the gnarly currency support in localeconv(), the standards
     don't include any functions for generalized currency formatting.

     LC_COLLATE does not make sense for many languages.  Use of LC_MONETARY
     could lead to misleading results until we have a real time currency
     conversion function.  LC_NUMERIC and LC_TIME are personal choices and
     should not be wrapped up with the other categories.

     Multibyte locales aren't supported for static binaries.

NetBSD 9.99                    October 24, 2021                    NetBSD 9.99