xref: /freebsd/lib/libc/locale/setlocale.3 (revision b52b9d56d4e96089873a75f9e29062eec19fabba)
1.\" Copyright (c) 1993
2.\"	The Regents of the University of California.  All rights reserved.
3.\"
4.\" This code is derived from software contributed to Berkeley by
5.\" Donn Seeley at BSDI.
6.\"
7.\" Redistribution and use in source and binary forms, with or without
8.\" modification, are permitted provided that the following conditions
9.\" are met:
10.\" 1. Redistributions of source code must retain the above copyright
11.\"    notice, this list of conditions and the following disclaimer.
12.\" 2. Redistributions in binary form must reproduce the above copyright
13.\"    notice, this list of conditions and the following disclaimer in the
14.\"    documentation and/or other materials provided with the distribution.
15.\" 3. All advertising materials mentioning features or use of this software
16.\"    must display the following acknowledgement:
17.\"	This product includes software developed by the University of
18.\"	California, Berkeley and its contributors.
19.\" 4. Neither the name of the University nor the names of its contributors
20.\"    may be used to endorse or promote products derived from this software
21.\"    without specific prior written permission.
22.\"
23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33.\" SUCH DAMAGE.
34.\"
35.\"	@(#)setlocale.3	8.1 (Berkeley) 6/9/93
36.\" $FreeBSD$
37.\"
38.Dd June 9, 1993
39.Dt SETLOCALE 3
40.Os
41.Sh NAME
42.Nm setlocale ,
43.Nm localeconv
44.Nd natural language formatting for C
45.Sh LIBRARY
46.Lb libc
47.Sh SYNOPSIS
48.In locale.h
49.Ft char *
50.Fn setlocale "int category" "const char *locale"
51.Ft struct lconv *
52.Fn localeconv "void"
53.Sh DESCRIPTION
54The
55.Fn setlocale
56function sets the C library's notion
57of natural language formatting style
58for particular sets of routines.
59Each such style is called a
60.Sq locale
61and is invoked using an appropriate name passed as a C string.
62The
63.Fn localeconv
64routine returns the current locale's parameters
65for formatting numbers.
66.Pp
67The
68.Fn setlocale
69function recognizes several categories of routines.
70These are the categories and the sets of routines they select:
71.Pp
72.Bl -tag -width LC_MONETARY
73.It Dv LC_ALL
74Set the entire locale generically.
75.It Dv LC_COLLATE
76Set a locale for string collation routines.
77This controls alphabetic ordering in
78.Fn strcoll
79and
80.Fn strxfrm .
81.It Dv LC_CTYPE
82Set a locale for the
83.Xr ctype 3 ,
84.Xr mbrune 3 ,
85.Xr multibyte 3
86and
87.Xr rune 3
88functions.
89This controls recognition of upper and lower case,
90alphabetic or non-alphabetic characters,
91and so on.  The real work is done by the
92.Fn setrunelocale
93function.
94.It Dv LC_MESSAGES
95Set a locale for message catalogs, see
96.Xr catopen 3
97function.
98.It Dv LC_MONETARY
99Set a locale for formatting monetary values;
100this affects the
101.Fn localeconv
102function.
103.It Dv LC_NUMERIC
104Set a locale for formatting numbers.
105This controls the formatting of decimal points
106in input and output of floating point numbers
107in functions such as
108.Fn printf
109and
110.Fn scanf ,
111as well as values returned by
112.Fn localeconv .
113.It Dv LC_TIME
114Set a locale for formatting dates and times using the
115.Fn strftime
116function.
117.El
118.Pp
119Only three locales are defined by default,
120the empty string
121.Li "\&""\|""
122which denotes the native environment, and the
123.Li "\&""C""
124and
125.Li "\&""POSIX""
126locales, which denote the C language environment.
127A
128.Fa locale
129argument of
130.Dv NULL
131causes
132.Fn setlocale
133to return the current locale.
134By default, C programs start in the
135.Li "\&""C""
136locale.
137The only function in the library that sets the locale is
138.Fn setlocale ;
139the locale is never changed as a side effect of some other routine.
140.Pp
141The
142.Fn localeconv
143function returns a pointer to a structure
144which provides parameters for formatting numbers,
145especially currency values:
146.Bd -literal -offset indent
147struct lconv {
148	char	*decimal_point;
149	char	*thousands_sep;
150	char	*grouping;
151	char	*int_curr_symbol;
152	char	*currency_symbol;
153	char	*mon_decimal_point;
154	char	*mon_thousands_sep;
155	char	*mon_grouping;
156	char	*positive_sign;
157	char	*negative_sign;
158	char	int_frac_digits;
159	char	frac_digits;
160	char	p_cs_precedes;
161	char	p_sep_by_space;
162	char	n_cs_precedes;
163	char	n_sep_by_space;
164	char	p_sign_posn;
165	char	n_sign_posn;
166};
167.Ed
168.Pp
169The individual fields have the following meanings:
170.Pp
171.Bl -tag -width mon_decimal_point
172.It Fa decimal_point
173The decimal point character, except for currency values.
174.It Fa thousands_sep
175The separator between groups of digits
176before the decimal point, except for currency values.
177.It Fa grouping
178The sizes of the groups of digits, except for currency values.
179This is a pointer to a vector of integers, each of size
180.Va char ,
181representing group size from low order digit groups
182to high order (right to left).
183The list may be terminated with 0 or
184.Dv CHAR_MAX .
185If the list is terminated with 0,
186the last group size before the 0 is repeated to account for all the digits.
187If the list is terminated with
188.Dv CHAR_MAX ,
189no more grouping is performed.
190.It Fa int_curr_symbol
191The standardized international currency symbol.
192.It Fa currency_symbol
193The local currency symbol.
194.It Fa mon_decimal_point
195The decimal point character for currency values.
196.It Fa mon_thousands_sep
197The separator for digit groups in currency values.
198.It Fa mon_grouping
199Like
200.Fa grouping
201but for currency values.
202.It Fa positive_sign
203The character used to denote nonnegative currency values,
204usually the empty string.
205.It Fa negative_sign
206The character used to denote negative currency values,
207usually a minus sign.
208.It Fa int_frac_digits
209The number of digits after the decimal point
210in an international-style currency value.
211.It Fa frac_digits
212The number of digits after the decimal point
213in the local style for currency values.
214.It Fa p_cs_precedes
2151 if the currency symbol precedes the currency value
216for nonnegative values, 0 if it follows.
217.It Fa p_sep_by_space
2181 if a space is inserted between the currency symbol
219and the currency value for nonnegative values, 0 otherwise.
220.It Fa n_cs_precedes
221Like
222.Fa p_cs_precedes
223but for negative values.
224.It Fa n_sep_by_space
225Like
226.Fa p_sep_by_space
227but for negative values.
228.It Fa p_sign_posn
229The location of the
230.Fa positive_sign
231with respect to a nonnegative quantity and the
232.Fa currency_symbol ,
233coded as follows:
234.Bl -tag -width 3n -compact
235.It Li 0
236Parentheses around the entire string.
237.It Li 1
238Before the string.
239.It Li 2
240After the string.
241.It Li 3
242Just before
243.Fa currency_symbol .
244.It Li 4
245Just after
246.Fa currency_symbol .
247.El
248.It Fa n_sign_posn
249Like
250.Fa p_sign_posn
251but for negative currency values.
252.El
253.Pp
254Unless mentioned above,
255an empty string as a value for a field
256indicates a zero length result or
257a value that is not in the current locale.
258A
259.Dv CHAR_MAX
260result similarly denotes an unavailable value.
261.Sh RETURN VALUES
262Upon successful completion,
263.Fn setlocale
264returns the string associated with the specified
265.Fa category
266for the requested
267.Fa locale .
268The
269.Fn setlocale
270function returns
271.Dv NULL
272and fails to change the locale
273if the given combination of
274.Fa category
275and
276.Fa locale
277makes no sense.
278The
279.Fn localeconv
280function returns a pointer to a static object
281which may be altered by later calls to
282.Fn setlocale
283or
284.Fn localeconv .
285.Sh FILES
286.Bl -tag -width /usr/share/locale/locale/category -compact
287.It Pa $PATH_LOCALE/ Ns Em locale/category
288.It Pa /usr/share/locale/ Ns Em locale/category
289locale file for the locale
290.Em locale
291and the category
292.Em category .
293.El
294.Sh SEE ALSO
295.Xr colldef 1 ,
296.Xr mklocale 1 ,
297.Xr catopen 3 ,
298.Xr ctype 3 ,
299.Xr mbrune 3 ,
300.Xr multibyte 3 ,
301.Xr rune 3 ,
302.Xr strcoll 3 ,
303.Xr strxfrm 3 ,
304.Xr euc 4 ,
305.Xr utf2 4
306.Sh STANDARDS
307The
308.Fn setlocale
309and
310.Fn localeconv
311functions conform to
312.St -isoC .
313.Sh HISTORY
314The
315.Fn setlocale
316and
317.Fn localeconv
318functions first appeared in
319.Bx 4.4 .
320