[apple/libc.git] / locale / setlocale.3

.\" Copyright (c) 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" Donn Seeley at BSDI.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"	@(#)setlocale.3	8.1 (Berkeley) 6/9/93
.\" $FreeBSD: src/lib/libc/locale/setlocale.3,v 1.15.2.5 2001/12/14 18:33:55 ru Exp $
.\"
.Dd June 9, 1993
.Dt SETLOCALE 3
.Os
.Sh NAME
.Nm setlocale ,
.Nm localeconv
.Nd natural language formatting for C
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In locale.h
.Ft char *
.Fn setlocale "int category" "const char *locale"
.Ft struct lconv *
.Fn localeconv "void"
.Sh DESCRIPTION
The
.Fn setlocale
function sets the C library's notion
of natural language formatting style
for particular sets of routines.
Each such style is called a
.Sq locale
and is invoked using an appropriate name passed as a C string.
The
.Fn localeconv
routine returns the current locale's parameters
for formatting numbers.
.Pp
The
.Fn setlocale
function recognizes several categories of routines.
These are the categories and the sets of routines they select:
.Pp
.Bl -tag -width LC_MONETARY
.It Dv LC_ALL
Set the entire locale generically.
.It Dv LC_COLLATE
Set a locale for string collation routines.
This controls alphabetic ordering in
.Fn strcoll
and
.Fn strxfrm .
.It Dv LC_CTYPE
Set a locale for the
.Xr ctype 3 ,
.Xr mbrune 3 ,
.Xr multibyte 3
and
.Xr rune 3
functions.
This controls recognition of upper and lower case,
alphabetic or non-alphabetic characters,
and so on.  The real work is done by the
.Fn setrunelocale
function.
.It Dv LC_MESSAGES
Set a locale for message catalogs, see
.Xr catopen 3
function.
.It Dv LC_MONETARY
Set a locale for formatting monetary values;
this affects the
.Fn localeconv
function.
.It Dv 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
.Fn printf
and
.Fn scanf ,
as well as values returned by
.Fn localeconv .
.It Dv LC_TIME
Set a locale for formatting dates and times using the
.Fn strftime
function.
.El
.Pp
Only three locales are defined by default,
the empty string
.Li "\&""\|""
which denotes the native environment, and the
.Li "\&""C""
and
.Li "\&""POSIX""
locales, which denote the C language environment.
A
.Fa locale
argument of
.Dv NULL
causes
.Fn setlocale
to return the current locale.
By default, C programs start in the
.Li "\&""C""
locale.
The only function in the library that sets the locale is
.Fn setlocale ;
the locale is never changed as a side effect of some other routine.
.Pp
The
.Fn localeconv
function returns a pointer to a structure
which provides parameters for formatting numbers,
especially currency values:
.Bd -literal -offset indent
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;
};
.Ed
.Pp
The individual fields have the following meanings:
.Pp
.Bl -tag -width mon_decimal_point
.It Fa decimal_point
The decimal point character, except for currency values.
.It Fa thousands_sep
The separator between groups of digits
before the decimal point, except for currency values.
.It Fa grouping
The sizes of the groups of digits, except for currency values.
This is a pointer to a vector of integers, each of size
.Va char ,
representing group size from low order digit groups
to high order (right to left).
The list may be terminated with 0 or
.Dv 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
.Dv CHAR_MAX ,
no more grouping is performed.
.It Fa int_curr_symbol
The standardized international currency symbol.
.It Fa currency_symbol
The local currency symbol.
.It Fa mon_decimal_point
The decimal point character for currency values.
.It Fa mon_thousands_sep
The separator for digit groups in currency values.
.It Fa mon_grouping
Like
.Fa grouping
but for currency values.
.It Fa positive_sign
The character used to denote nonnegative currency values,
usually the empty string.
.It Fa negative_sign
The character used to denote negative currency values,
usually a minus sign.
.It Fa int_frac_digits
The number of digits after the decimal point
in an international-style currency value.
.It Fa frac_digits
The number of digits after the decimal point
in the local style for currency values.
.It Fa p_cs_precedes
1 if the currency symbol precedes the currency value
for nonnegative values, 0 if it follows.
.It Fa p_sep_by_space
1 if a space is inserted between the currency symbol
and the currency value for nonnegative values, 0 otherwise.
.It Fa n_cs_precedes
Like
.Fa p_cs_precedes
but for negative values.
.It Fa n_sep_by_space
Like
.Fa p_sep_by_space
but for negative values.
.It Fa p_sign_posn
The location of the
.Fa positive_sign
with respect to a nonnegative quantity and the
.Fa currency_symbol ,
coded as follows:
.Bl -tag -width 3n -compact
.It Li 0
Parentheses around the entire string.
.It Li 1
Before the string.
.It Li 2
After the string.
.It Li 3
Just before
.Fa currency_symbol .
.It Li 4
Just after
.Fa currency_symbol .
.El
.It Fa n_sign_posn
Like
.Fa p_sign_posn
but for negative currency values.
.El
.Pp
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
.Dv CHAR_MAX
result similarly denotes an unavailable value.
.Sh RETURN VALUES
The
.Fn setlocale
function returns
.Dv NULL
and fails to change the locale
if the given combination of
.Fa category
and
.Fa locale
makes no sense.
The
.Fn localeconv
function returns a pointer to a static object
which may be altered by later calls to
.Fn setlocale
or
.Fn localeconv .
.Sh FILES
.Bl -tag -width /usr/share/locale/locale/category -compact
.It Pa $PATH_LOCALE/ Ns Em locale/category
.It Pa /usr/share/locale/ Ns Em locale/category
locale file for the locale
.Em locale
and the category
.Em category .
.El
.Sh SEE ALSO
.Xr colldef 1 ,
.Xr mklocale 1 ,
.Xr catopen 3 ,
.Xr ctype 3 ,
.Xr mbrune 3 ,
.Xr multibyte 3 ,
.Xr rune 3 ,
.Xr strcoll 3 ,
.Xr strxfrm 3 ,
.Xr euc 4 ,
.Xr utf2 4
.Sh STANDARDS
The
.Fn setlocale
and
.Fn localeconv
functions conform to
.St -isoC .
.Sh HISTORY
The
.Fn setlocale
and
.Fn localeconv
functions first appeared in
.Bx 4.4 .
.Sh BUGS
The current implementation supports only the
.Li "\&""C""
and
.Li "\&""POSIX""
locales for all but the 
.Dv LC_COLLATE ,
.Dv LC_CTYPE ,
and
.Dv LC_TIME
categories.
.Pp
In spite of the gnarly currency support in
.Fn localeconv ,
the standards don't include any functions
for generalized currency formatting.
.Pp
Use of
.Dv LC_MONETARY
could lead to misleading results until we have a real time currency
conversion function.
.Dv LC_NUMERIC
and
.Dv LC_TIME
are personal choices and should not be wrapped up with the other categories.
Commit	Line	Data
5b2abdfb A	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: src/lib/libc/locale/setlocale.3,v 1.15.2.5 2001/12/14 18:33:55 ru Exp $
	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
	54	The
	55	.Fn setlocale
	56	function sets the C library's notion
	57	of natural language formatting style
	58	for particular sets of routines.
	59	Each such style is called a
	60	.Sq locale
	61	and is invoked using an appropriate name passed as a C string.
	62	The
	63	.Fn localeconv
	64	routine returns the current locale's parameters
65	for formatting numbers.
66	.Pp
67	The
68	.Fn setlocale
69	function recognizes several categories of routines.
70	These are the categories and the sets of routines they select:
71	.Pp
72	.Bl -tag -width LC_MONETARY
73	.It Dv LC_ALL
74	Set the entire locale generically.
75	.It Dv LC_COLLATE
76	Set a locale for string collation routines.
77	This controls alphabetic ordering in
78	.Fn strcoll
79	and
80	.Fn strxfrm .
81	.It Dv LC_CTYPE
82	Set a locale for the
83	.Xr ctype 3 ,
84	.Xr mbrune 3 ,
85	.Xr multibyte 3
86	and
87	.Xr rune 3
88	functions.
89	This controls recognition of upper and lower case,
90	alphabetic or non-alphabetic characters,
91	and so on. The real work is done by the
92	.Fn setrunelocale
93	function.
94	.It Dv LC_MESSAGES
95	Set a locale for message catalogs, see
96	.Xr catopen 3
97	function.
98	.It Dv LC_MONETARY
99	Set a locale for formatting monetary values;
100	this affects the
101	.Fn localeconv
102	function.
103	.It Dv LC_NUMERIC
104	Set a locale for formatting numbers.
105	This controls the formatting of decimal points
106	in input and output of floating point numbers
107	in functions such as
108	.Fn printf
109	and
110	.Fn scanf ,
111	as well as values returned by
112	.Fn localeconv .
113	.It Dv LC_TIME
114	Set a locale for formatting dates and times using the
115	.Fn strftime
116	function.
117	.El
118	.Pp
119	Only three locales are defined by default,
120	the empty string
121	.Li "\&""\\|""
122	which denotes the native environment, and the
123	.Li "\&""C""
124	and
125	.Li "\&""POSIX""
126	locales, which denote the C language environment.
127	A
128	.Fa locale
129	argument of
130	.Dv NULL
131	causes
132	.Fn setlocale
133	to return the current locale.
134	By default, C programs start in the
135	.Li "\&""C""
136	locale.
137	The only function in the library that sets the locale is
138	.Fn setlocale ;
139	the locale is never changed as a side effect of some other routine.
140	.Pp
141	The
142	.Fn localeconv
143	function returns a pointer to a structure
144	which provides parameters for formatting numbers,
145	especially currency values:
146	.Bd -literal -offset indent
147	struct 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
169	The individual fields have the following meanings:
170	.Pp
171	.Bl -tag -width mon_decimal_point
172	.It Fa decimal_point
173	The decimal point character, except for currency values.
174	.It Fa thousands_sep
175	The separator between groups of digits
176	before the decimal point, except for currency values.
177	.It Fa grouping
178	The sizes of the groups of digits, except for currency values.
179	This is a pointer to a vector of integers, each of size
180	.Va char ,
181	representing group size from low order digit groups
182	to high order (right to left).
183	The list may be terminated with 0 or
184	.Dv CHAR_MAX .
185	If the list is terminated with 0,
186	the last group size before the 0 is repeated to account for all the digits.
187	If the list is terminated with
188	.Dv CHAR_MAX ,
189	no more grouping is performed.
190	.It Fa int_curr_symbol
191	The standardized international currency symbol.
192	.It Fa currency_symbol
193	The local currency symbol.
194	.It Fa mon_decimal_point
195	The decimal point character for currency values.
196	.It Fa mon_thousands_sep
197	The separator for digit groups in currency values.
198	.It Fa mon_grouping
199	Like
200	.Fa grouping
201	but for currency values.
202	.It Fa positive_sign
203	The character used to denote nonnegative currency values,
204	usually the empty string.
205	.It Fa negative_sign
206	The character used to denote negative currency values,
207	usually a minus sign.
208	.It Fa int_frac_digits
209	The number of digits after the decimal point
210	in an international-style currency value.
211	.It Fa frac_digits
212	The number of digits after the decimal point
213	in the local style for currency values.
214	.It Fa p_cs_precedes
215	1 if the currency symbol precedes the currency value
216	for nonnegative values, 0 if it follows.
217	.It Fa p_sep_by_space
218	1 if a space is inserted between the currency symbol
219	and the currency value for nonnegative values, 0 otherwise.
220	.It Fa n_cs_precedes
221	Like
222	.Fa p_cs_precedes
223	but for negative values.
224	.It Fa n_sep_by_space
225	Like
226	.Fa p_sep_by_space
227	but for negative values.
228	.It Fa p_sign_posn
229	The location of the
230	.Fa positive_sign
231	with respect to a nonnegative quantity and the
232	.Fa currency_symbol ,
233	coded as follows:
234	.Bl -tag -width 3n -compact
235	.It Li 0
236	Parentheses around the entire string.
237	.It Li 1
238	Before the string.
239	.It Li 2
240	After the string.
241	.It Li 3
242	Just before
243	.Fa currency_symbol .
244	.It Li 4
245	Just after
246	.Fa currency_symbol .
247	.El
248	.It Fa n_sign_posn
249	Like
250	.Fa p_sign_posn
251	but for negative currency values.
252	.El
253	.Pp
254	Unless mentioned above,
255	an empty string as a value for a field
256	indicates a zero length result or
257	a value that is not in the current locale.
258	A
259	.Dv CHAR_MAX
260	result similarly denotes an unavailable value.
261	.Sh RETURN VALUES
262	The
263	.Fn setlocale
264	function returns
265	.Dv NULL
266	and fails to change the locale
267	if the given combination of
268	.Fa category
269	and
270	.Fa locale
271	makes no sense.
272	The
273	.Fn localeconv
274	function returns a pointer to a static object
275	which may be altered by later calls to
276	.Fn setlocale
277	or
278	.Fn localeconv .
279	.Sh FILES
280	.Bl -tag -width /usr/share/locale/locale/category -compact
281	.It Pa $PATH_LOCALE/ Ns Em locale/category
282	.It Pa /usr/share/locale/ Ns Em locale/category
283	locale file for the locale
284	.Em locale
285	and the category
286	.Em category .
287	.El
288	.Sh SEE ALSO
289	.Xr colldef 1 ,
290	.Xr mklocale 1 ,
291	.Xr catopen 3 ,
292	.Xr ctype 3 ,
293	.Xr mbrune 3 ,
294	.Xr multibyte 3 ,
295	.Xr rune 3 ,
296	.Xr strcoll 3 ,
297	.Xr strxfrm 3 ,
298	.Xr euc 4 ,
299	.Xr utf2 4
300	.Sh STANDARDS
301	The
302	.Fn setlocale
303	and
304	.Fn localeconv
305	functions conform to
306	.St -isoC .
307	.Sh HISTORY
308	The
309	.Fn setlocale
310	and
311	.Fn localeconv
312	functions first appeared in
313	.Bx 4.4 .
314	.Sh BUGS
315	The current implementation supports only the
316	.Li "\&""C""
317	and
318	.Li "\&""POSIX""
319	locales for all but the
320	.Dv LC_COLLATE ,
321	.Dv LC_CTYPE ,
322	and
323	.Dv LC_TIME
324	categories.
325	.Pp
326	In spite of the gnarly currency support in
327	.Fn localeconv ,
328	the standards don't include any functions
329	for generalized currency formatting.
330	.Pp
331	Use of
332	.Dv LC_MONETARY
333	could lead to misleading results until we have a real time currency
334	conversion function.
335	.Dv LC_NUMERIC
336	and
337	.Dv LC_TIME
338	are personal choices and should not be wrapped up with the other categories.