aboutsummaryrefslogtreecommitdiffstats
path: root/lib/libc/locale/setlocale.3
blob: 18db81120cd9431cbffc6ac0ddc76806bd66ef89 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
.\" 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
.\"
.Dd June 9, 1993
.Dt SETLOCALE 3
.Os
.Sh NAME
.Nm setlocale ,
.Nm localeconv
.Nd natural language formatting for C
.Sh SYNOPSIS
.Fd #include <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_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 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 -ansiC .
.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.