Provided by: manpages-pt-dev_20040726-4_all
setlocale - set the current locale.
char *setlocale(int category, const char * locale);
The setlocale() function is used to set or query the program’s current
If locale is not NULL, the program’s current locale is modified
according to the arguments. The argument category determines which
parts of the program’s current locale should be modified.
LC_ALL for all of the locale.
for regular expression matching (it determines the meaning of
range expressions and equivalence classes) and string collation.
for regular expression matching, character classification,
conversion, case-sensitive comparison, and wide character
for localizable natural-language messages.
for monetary formatting.
for number formatting (such as the decimal point and the
for time and date formatting.
The argument locale is a pointer to a character string containing the
required setting of category. Such a string is either a well-known
constant like "C" or "da_DK" (see below), or an opaque string that was
returned by another call of setlocale.
If locale is "", each part of the locale that should be modified is set
according to the environment variables. The details are implementation
dependent. For glibc, first (regardless of category), the environment
variable LC_ALL is inspected, next the environment variable with the
same name as the category (LC_COLLATE, LC_CTYPE, LC_MESSAGES,
LC_MONETARY, LC_NUMERIC, LC_TIME) and finally the environment variable
LANG. The first existing environment variable is used. If its value
is not a valid locale specification, the locale is unchanged, and
setlocale returns NULL.
The locale "C" or "POSIX" is a portable locale; its LC_CTYPE part
corresponds to the 7-bit ASCII character set.
A locale name is typically of the form
language[_territory][.codeset][@modifier], where language is an ISO 639
language code, territory is an ISO 3166 country code, and codeset is a
character set or encoding identifier like ISO-8859-1 or UTF-8.
If locale is NULL, the current locale is only queried, not modified.
On startup of the main program, the portable "C" locale is selected as
default. A program may be made portable to all locales by calling
setlocale(LC_ALL, "" ) after program initialization, by using the
values returned from a localeconv() call for locale - dependent
information, by using the multi-byte and wide character functions for
text processing if MB_CUR_MAX > 1, and by using strcoll(), wstrcoll()
or strxfrm(), wstrxfrm() to compare strings.
A successful call to setlocale() returns a string that corresponds to
the locale set. This string may be allocated in static storage. The
string returned is such that a subsequent call with that string and its
associated category will restore that part of the process’s locale. The
return value is NULL if the request cannot be honored.
ANSI C, POSIX.1
Linux (that is, GNU libc) supports the portable locales "C" and
"POSIX". In the good old days there used to be support for the
European Latin-1 "ISO-8859-1" locale (e.g. in libc-4.5.21 and
libc-4.6.27), and the Russian "KOI-8" (more precisely, "koi-8r") locale
(e.g. in libc-4.6.27), so that having an environment variable
LC_CTYPE=ISO-8859-1 sufficed to make isprint() return the right answer.
These days non-English speaking Europeans have to work a bit harder,
and must install actual locale files.
locale(1), localedef(1), strcoll(3), isalpha(3), localeconv(3),
strftime(3), charsets(4), locale(7)