NAME
setlocale
—
natural language formatting for
C
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include
<locale.h>
char *
setlocale
(int category,
const char *locale);
DESCRIPTION
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
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
() andstrxfrm
(). LC_CTYPE
- Set a locale for the ctype(3) and multibyte(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, see catopen(3) function.
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
() andscanf
(), as well as values returned bylocaleconv
(). 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. An argument of
""
will determine the name of the new
locale taking into account the environment variables LANG and LC_*. If these
environment variables yield a locale that is invalid, NULL will be returned
and the current locale will remain unchanged. By default, C programs start
in the "C"
locale. 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.
RETURN VALUES
Upon successful completion, setlocale
()
returns the string associated with the specified
category for the requested
locale. The setlocale
()
function returns NULL
and fails to change the locale
if the given combination of category and
locale makes no sense.
FILES
- $PATH_LOCALE/locale/category
- /usr/share/locale/locale/category
- locale file for the locale locale and the category category.
- /usr/local/share/locale/locale/category
- locale file for the locale locale and the category category.
ERRORS
No errors are defined.
SEE ALSO
colldef(1), mklocale(1), catopen(3), ctype(3), localeconv(3), multibyte(3), strcoll(3), strxfrm(3), euc(5), utf8(5), environ(7)
STANDARDS
The setlocale
() function conforms to
ISO/IEC 9899:1999
(“ISO C99”).
HISTORY
The setlocale
() function first appeared in
4.4BSD.