1NEWLOCALE(3)               Linux Programmer's Manual              NEWLOCALE(3)
2
3
4

NAME

6       newlocale, freelocale - create, modify, and free a locale object
7

SYNOPSIS

9       #include <locale.h>
10
11       locale_t newlocale(int category_mask, const char *locale,
12                          locale_t base);
13
14       void freelocale(locale_t locobj);
15
16   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
17
18       newlocale(), freelocale():
19           Since glibc 2.10:
20                  _XOPEN_SOURCE >= 700
21           Before glibc 2.10:
22                  _GNU_SOURCE
23

DESCRIPTION

25       The  newlocale()  function  creates a new locale object, or modifies an
26       existing object, returning a reference to the new or modified object as
27       the function result.  Whether the call creates a new object or modifies
28       an existing object is determined by the value of base:
29
30       *  If base is (locale_t) 0, a new object is created.
31
32       *  If base refers to valid existing locale object (i.e., an object  re‐
33          turned by a previous call to newlocale() or duplocale(3)), then that
34          object is modified by the call.  If the call is successful, the con‐
35          tents of base are unspecified (in particular, the object referred to
36          by base may be freed, and a new  object  created).   Therefore,  the
37          caller  should  ensure  that  it stops using base before the call to
38          newlocale(), and should subsequently refer to  the  modified  object
39          via  the  reference  returned  as  the function result.  If the call
40          fails, the contents of base remain valid and unchanged.
41
42       If base is the  special  locale  object  LC_GLOBAL_LOCALE  (see  duplo‐
43       cale(3)),  or is not (locale_t) 0 and is not a valid locale object han‐
44       dle, the behavior is undefined.
45
46       The category_mask argument is a bit mask that specifies the locale cat‐
47       egories that are to be set in a newly created locale object or modified
48       in an existing object.  The mask is constructed by a bitwise OR of  the
49       constants LC_ADDRESS_MASK, LC_CTYPE_MASK, LC_COLLATE_MASK, LC_IDENTIFI‐
50       CATION_MASK, LC_MEASUREMENT_MASK,  LC_MESSAGES_MASK,  LC_MONETARY_MASK,
51       LC_NUMERIC_MASK,  LC_NAME_MASK,  LC_PAPER_MASK,  LC_TELEPHONE_MASK, and
52       LC_TIME_MASK.  Alternatively, the mask can be specified as LC_ALL_MASK,
53       which is equivalent to ORing all of the preceding constants.
54
55       For  each category specified in category_mask, the locale data from lo‐
56       cale will be used in the object returned by newlocale().  If a new  lo‐
57       cale  object is being created, data for all categories not specified in
58       category_mask is taken from the default ("POSIX") locale.
59
60       The following preset values of locale are defined  for  all  categories
61       that can be specified in category_mask:
62
63       "POSIX"
64              A minimal locale environment for C language programs.
65
66       "C"    Equivalent to "POSIX".
67
68       ""     An  implementation-defined  native  environment corresponding to
69              the values of the LC_* and LANG environment variables  (see  lo‐
70              cale(7)).
71
72   freelocale()
73       The freelocale() function deallocates the resources associated with lo‐
74       cobj, a locale object previously returned by a call to  newlocale()  or
75       duplocale(3).  If locobj is LC_GLOBAL_LOCALE or is not valid locale ob‐
76       ject handle, the results are undefined.
77
78       Once a locale object has been freed, the program should make no further
79       use of it.
80

RETURN VALUE

82       On  success,  newlocale() returns a handle that can be used in calls to
83       duplocale(3), freelocale(), and other functions that  take  a  locale_t
84       argument.   On  error, newlocale() returns (locale_t) 0, and sets errno
85       to indicate the cause of the error.
86

ERRORS

88       EINVAL One or more bits in category_mask do not correspond to  a  valid
89              locale category.
90
91       EINVAL locale is NULL.
92
93       ENOENT locale is not a string pointer referring to a valid locale.
94
95       ENOMEM Insufficient memory to create a locale object.
96

VERSIONS

98       The  newlocale()  and  freelocale() functions first appeared in version
99       2.3 of the GNU C library.
100

CONFORMING TO

102       POSIX.1-2008.
103

NOTES

105       Each locale object created by newlocale() should be  deallocated  using
106       freelocale().
107

EXAMPLES

109       The  program  below  takes up to two command-line arguments, which each
110       identify locales.  The first argument is required, and is used  to  set
111       the  LC_NUMERIC  category in a locale object created using newlocale().
112       The second command-line argument is optional; if it is present,  it  is
113       used to set the LC_TIME category of the locale object.
114
115       Having  created and initialized the locale object, the program then ap‐
116       plies it using uselocale(3), and then tests the effect  of  the  locale
117       changes by:
118
119       1. Displaying  a  floating-point  number  with a fractional part.  This
120          output will be affected by the LC_NUMERIC setting.   In  many  Euro‐
121          pean-language  locales,  the  fractional part of the number is sepa‐
122          rated from the integer part using a comma, rather than a period.
123
124       2. Displaying the date.  The format and language of the output will  be
125          affected by the LC_TIME setting.
126
127       The following shell sessions show some example runs of this program.
128
129       Set the LC_NUMERIC category to fr_FR (French):
130
131           $ ./a.out fr_FR
132           123456,789
133           Fri Mar  7 00:25:08 2014
134
135       Set the LC_NUMERIC category to fr_FR (French), and the LC_TIME category
136       to it_IT (Italian):
137
138           $ ./a.out fr_FR it_IT
139           123456,789
140           ven 07 mar 2014 00:26:01 CET
141
142       Specify the LC_TIME setting as an empty string, which causes the  value
143       to  be  taken  from environment variable settings (which, here, specify
144       mi_NZ, New Zealand Māori):
145
146           $ LC_ALL=mi_NZ ./a.out fr_FR ""
147           123456,789
148           Te Paraire, te 07 o Poutū-te-rangi, 2014 00:38:44 CET
149
150   Program source
151       #define _XOPEN_SOURCE 700
152       #include <stdio.h>
153       #include <stdlib.h>
154       #include <locale.h>
155       #include <time.h>
156
157       #define errExit(msg)    do { perror(msg); exit(EXIT_FAILURE); \
158                               } while (0)
159
160       int
161       main(int argc, char *argv[])
162       {
163           char buf[100];
164           time_t t;
165           size_t s;
166           struct tm *tm;
167           locale_t loc, nloc;
168
169           if (argc < 2) {
170               fprintf(stderr, "Usage: %s locale1 [locale2]\n", argv[0]);
171               exit(EXIT_FAILURE);
172           }
173
174           /* Create a new locale object, taking the LC_NUMERIC settings
175              from the locale specified in argv[1] */
176
177           loc = newlocale(LC_NUMERIC_MASK, argv[1], (locale_t) 0);
178           if (loc == (locale_t) 0)
179               errExit("newlocale");
180
181           /* If a second command-line argument was specified, modify the
182              locale object to take the LC_TIME settings from the locale
183              specified in argv[2]. We assign the result of this newlocale()
184              call to 'nloc' rather than 'loc', since in some cases, we might
185              want to preserve 'loc' if this call fails. */
186
187           if (argc > 2) {
188               nloc = newlocale(LC_TIME_MASK, argv[2], loc);
189               if (nloc == (locale_t) 0)
190                   errExit("newlocale");
191               loc = nloc;
192           }
193
194           /* Apply the newly created locale to this thread */
195
196           uselocale(loc);
197
198           /* Test effect of LC_NUMERIC */
199
200           printf("%8.3f\n", 123456.789);
201
202           /* Test effect of LC_TIME */
203
204           t = time(NULL);
205           tm = localtime(&t);
206           if (tm == NULL)
207               errExit("time");
208
209           s = strftime(buf, sizeof(buf), "%c", tm);
210           if (s == 0)
211               errExit("strftime");
212
213           printf("%s\n", buf);
214
215           /* Free the locale object */
216
217           uselocale(LC_GLOBAL_HANDLE);    /* So 'loc' is no longer in use */
218           freelocale(loc);
219
220           exit(EXIT_SUCCESS);
221       }
222

SEE ALSO

224       locale(1), duplocale(3),  setlocale(3),  uselocale(3),  locale(5),  lo‐
225       cale(7)
226

COLOPHON

228       This  page  is  part of release 5.10 of the Linux man-pages project.  A
229       description of the project, information about reporting bugs,  and  the
230       latest     version     of     this    page,    can    be    found    at
231       https://www.kernel.org/doc/man-pages/.
232
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235Linux                             2020-11-01                      NEWLOCALE(3)
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