1newlocale(3) Library Functions Manual newlocale(3)
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6 newlocale, freelocale - create, modify, and free a locale object
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9 Standard C library (libc, -lc)
10
12 #include <locale.h>
13 locale_t newlocale(int category_mask, const char *locale,
15 locale_t base);
16 void freelocale(locale_t locobj);
17 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
19 newlocale(), freelocale():
21 Since glibc 2.10:
22 _XOPEN_SOURCE >= 700
23 Before glibc 2.10:
24 _GNU_SOURCE
25
27 The newlocale() function creates a new locale object, or modifies an
28 existing object, returning a reference to the new or modified object as
29 the function result. Whether the call creates a new object or modifies
30 an existing object is determined by the value of base:
31 • If base is (locale_t) 0, a new object is created.
33 • If base refers to valid existing locale object (i.e., an object re‐
35 turned by a previous call to newlocale() or duplocale(3)), then that
36 object is modified by the call. If the call is successful, the con‐
37 tents of base are unspecified (in particular, the object referred to
38 by base may be freed, and a new object created). Therefore, the
39 caller should ensure that it stops using base before the call to
40 newlocale(), and should subsequently refer to the modified object
41 via the reference returned as the function result. If the call
42 fails, the contents of base remain valid and unchanged.
43 If base is the special locale object LC_GLOBAL_LOCALE (see duplo‐
45 cale(3)), or is not (locale_t) 0 and is not a valid locale object han‐
46 dle, the behavior is undefined.
47 The category_mask argument is a bit mask that specifies the locale cat‐
49 egories that are to be set in a newly created locale object or modified
50 in an existing object. The mask is constructed by a bitwise OR of the
51 constants LC_ADDRESS_MASK, LC_CTYPE_MASK, LC_COLLATE_MASK, LC_IDENTIFI‐
52 CATION_MASK, LC_MEASUREMENT_MASK, LC_MESSAGES_MASK, LC_MONETARY_MASK,
53 LC_NUMERIC_MASK, LC_NAME_MASK, LC_PAPER_MASK, LC_TELEPHONE_MASK, and
54 LC_TIME_MASK. Alternatively, the mask can be specified as LC_ALL_MASK,
55 which is equivalent to ORing all of the preceding constants.
56 For each category specified in category_mask, the locale data from lo‐
58 cale will be used in the object returned by newlocale(). If a new lo‐
59 cale object is being created, data for all categories not specified in
60 category_mask is taken from the default ("POSIX") locale.
61 The following preset values of locale are defined for all categories
63 that can be specified in category_mask:
64 "POSIX"
66 A minimal locale environment for C language programs.
67 "C" Equivalent to "POSIX".
69 "" An implementation-defined native environment corresponding to
71 the values of the LC_* and LANG environment variables (see lo‐
72 cale(7)).
73 freelocale()
75 The freelocale() function deallocates the resources associated with lo‐
76 cobj, a locale object previously returned by a call to newlocale() or
77 duplocale(3). If locobj is LC_GLOBAL_LOCALE or is not valid locale ob‐
78 ject handle, the results are undefined.
79 Once a locale object has been freed, the program should make no further
81 use of it.
82
84 On success, newlocale() returns a handle that can be used in calls to
85 duplocale(3), freelocale(), and other functions that take a locale_t
86 argument. On error, newlocale() returns (locale_t) 0, and sets errno
87 to indicate the error.
88
90 EINVAL One or more bits in category_mask do not correspond to a valid
91 locale category.
92 EINVAL locale is NULL.
94 ENOENT locale is not a string pointer referring to a valid locale.
96 ENOMEM Insufficient memory to create a locale object.
98
100 POSIX.1-2008.
101
103 glibc 2.3.
104
106 Each locale object created by newlocale() should be deallocated using
107 freelocale().
108
110 The program below takes up to two command-line arguments, which each
111 identify locales. The first argument is required, and is used to set
112 the LC_NUMERIC category in a locale object created using newlocale().
113 The second command-line argument is optional; if it is present, it is
114 used to set the LC_TIME category of the locale object.
115 Having created and initialized the locale object, the program then ap‐
117 plies it using uselocale(3), and then tests the effect of the locale
118 changes by:
119 (1) Displaying a floating-point number with a fractional part. This
121 output will be affected by the LC_NUMERIC setting. In many Euro‐
122 pean-language locales, the fractional part of the number is sepa‐
123 rated from the integer part using a comma, rather than a period.
124 (2) Displaying the date. The format and language of the output will
126 be affected by the LC_TIME setting.
127 The following shell sessions show some example runs of this program.
129 Set the LC_NUMERIC category to fr_FR (French):
131 $ ./a.out fr_FR
133 123456,789
134 Fri Mar 7 00:25:08 2014
135 Set the LC_NUMERIC category to fr_FR (French), and the LC_TIME category
137 to it_IT (Italian):
138 $ ./a.out fr_FR it_IT
140 123456,789
141 ven 07 mar 2014 00:26:01 CET
142 Specify the LC_TIME setting as an empty string, which causes the value
144 to be taken from environment variable settings (which, here, specify
145 mi_NZ, New Zealand Māori):
146 $ LC_ALL=mi_NZ ./a.out fr_FR ""
148 123456,789
149 Te Paraire, te 07 o Poutū-te-rangi, 2014 00:38:44 CET
150 Program source
152 #define _XOPEN_SOURCE 700
153 #include <locale.h>
154 #include <stdio.h>
155 #include <stdlib.h>
156 #include <time.h>
157 #define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \
159 } while (0)
160 int
162 main(int argc, char *argv[])
163 {
164 char buf[100];
165 time_t t;
166 size_t s;
167 struct tm *tm;
168 locale_t loc, nloc;
169 if (argc < 2) {
171 fprintf(stderr, "Usage: %s locale1 [locale2]\n", argv[0]);
172 exit(EXIT_FAILURE);
173 }
174 /* Create a new locale object, taking the LC_NUMERIC settings
176 from the locale specified in argv[1]. */
177 loc = newlocale(LC_NUMERIC_MASK, argv[1], (locale_t) 0);
179 if (loc == (locale_t) 0)
180 errExit("newlocale");
181 /* If a second command-line argument was specified, modify the
183 locale object to take the LC_TIME settings from the locale
184 specified in argv[2]. We assign the result of this newlocale()
185 call to 'nloc' rather than 'loc', since in some cases, we might
186 want to preserve 'loc' if this call fails. */
187 if (argc > 2) {
189 nloc = newlocale(LC_TIME_MASK, argv[2], loc);
190 if (nloc == (locale_t) 0)
191 errExit("newlocale");
192 loc = nloc;
193 }
194 /* Apply the newly created locale to this thread. */
196 uselocale(loc);
198 /* Test effect of LC_NUMERIC. */
200 printf("%8.3f\n", 123456.789);
202 /* Test effect of LC_TIME. */
204 t = time(NULL);
206 tm = localtime(&t);
207 if (tm == NULL)
208 errExit("time");
209 s = strftime(buf, sizeof(buf), "%c", tm);
211 if (s == 0)
212 errExit("strftime");
213 printf("%s\n", buf);
215 /* Free the locale object. */
217 uselocale(LC_GLOBAL_LOCALE); /* So 'loc' is no longer in use */
219 freelocale(loc);
220 exit(EXIT_SUCCESS);
222 }
223
225 locale(1), duplocale(3), setlocale(3), uselocale(3), locale(5), lo‐
226 cale(7)
227Linux man-pages 6.04 2023-03-30 newlocale(3)