Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools


NEWLOCALE(3) Linux Programmer's Manual NEWLOCALE(3)


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


     #include <locale.h>
     locale_t newlocale(int category_mask, const char *locale,
                        locale_t base);
     void freelocale(locale_t locobj);
 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
     newlocale(), freelocale():
         Since glibc 2.10:
                _XOPEN_SOURCE >= 700
         Before glibc 2.10:


     The  newlocale()  function  creates a new locale object, or modifies an
     existing object, returning a reference to the new or modified object as
     the function result.  Whether the call creates a new object or modifies
     an existing object is determined by the value of base:
  • If base is (locale_t) 0, a new object is created.
  • If base refers to valid existing locale object (i.e., an object

returned by a previous call to newlocale() or duplocale(3)), then

        that object is modified by the call.  If the call is successful, the
        contents of base are unspecified (in particular, the object referred
        to by base may be freed, and a new object created).  Therefore,  the
        caller  should  ensure  that  it stops using base before the call to
        newlocale(), and should subsequently refer to  the  modified  object
        via  the  reference  returned  as  the function result.  If the call
        fails, the contents of base remain valid and unchanged.
     If base is the  special  locale  object  LC_GLOBAL_LOCALE  (see  duplo-
     cale(3)),  or is not (locale_t) 0 and is not a valid locale object han-
     dle, the behavior is undefined.
     The category_mask argument is a bit mask that specifies the locale cat-
     egories that are to be set in a newly created locale object or modified
     in an existing object.  The mask is constructed by a bitwise OR of  the
     LC_TIME_MASK.  Alternatively, the mask can be specified as LC_ALL_MASK,
     which is equivalent to ORing all of the preceding constants.
     For  each  category  specified  in  category_mask, the locale data from
     locale will be used in the object returned by newlocale().   If  a  new
     locale  object  is being created, data for all categories not specified
     in category_mask is taken from the default ("POSIX") locale.
     The following preset values of locale are defined  for  all  categories
     that can be specified in category_mask:
            A minimal locale environment for C language programs.
     "C"    Equivalent to "POSIX".
     ""     An  implementation-defined  native  environment corresponding to
            the values of the  LC_*  and  LANG  environment  variables  (see
     The  freelocale()  function  deallocates  the resources associated with
     locobj, a locale object previously returned by a call to newlocale() or
     duplocale(3).   If  locobj  is  LC_GLOBAL_LOCALE or is not valid locale
     object handle, the results are undefined.
     Once a locale object has been freed, the program should make no further
     use of it.


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


     EINVAL One or more bits in category_mask do not correspond to  a  valid
            locale category.
     EINVAL locale is NULL.
     ENOENT locale is not a string pointer referring to a valid locale.
     ENOMEM Insufficient memory to create a locale object.


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




     Each locale object created by newlocale() should be  deallocated  using


     The  program  below  takes up to two command-line arguments, which each
     identify locales.  The first argument is required, and is used  to  set
     the  LC_NUMERIC  category in a locale object created using newlocale().
     The second command-line argument is optional; if it is present,  it  is
     used to set the LC_TIME category of the locale object.
     Having  created  and  initialized  the  locale object, the program then
     applies it using uselocale(3), and then tests the effect of the  locale
     changes by:
     1. Displaying  a  floating-point  number  with a fractional part.  This
        output will be affected by the LC_NUMERIC setting.   In  many  Euro-
        pean-language  locales,  the  fractional part of the number is sepa-
        rated from the integer part using a comma, rather than a period.
     2. Displaying the date.  The format and language of the output will  be
        affected by the LC_TIME setting.
     The following shell sessions show some example runs of this program.
     Set the LC_NUMERIC category to fr_FR (French):
         $ ./a.out fr_FR 123456,789 Fri Mar  7 00:25:08 2014
     Set the LC_NUMERIC category to fr_FR (French), and the LC_TIME category
     to it_IT (Italian):
         $ ./a.out fr_FR it_IT 123456,789 ven 07 mar 2014 00:26:01 CET
     Specify the LC_TIME setting as an empty string, which causes the  value
     to  be  taken  from environment variable settings (which, here, specify
     mi_NZ, New Zealand Mori):
         $ LC_ALL=mi_NZ ./a.out fr_FR "" 123456,789  Te  Paraire,  te  07  o
         Pout-te-rangi, 2014 00:38:44 CET
 Program source
     #define   _XOPEN_SOURCE  700  #include  <stdio.h>  #include  <stdlib.h>
     #include <locale.h> #include <time.h>
     #define errExit(msg)    do { perror(msg); exit(EXIT_FAILURE); \
                             } while (0)
     int main(int argc, char *argv[]) {
         char buf[100];
         time_t t;
         size_t s;
         struct tm *tm;
         locale_t loc, nloc;
         if (argc < 2) {
             fprintf(stderr, "Usage: %s locale1 [locale2]\n", argv[0]);
         /* Create a new locale object, taking the LC_NUMERIC settings
            from the locale specified in argv[1] */
         loc = newlocale(LC_NUMERIC_MASK, argv[1], (locale_t) 0);
         if (loc == (locale_t) 0)
         /* If a second command-line argument was specified, modify the
            locale object to take the LC_TIME settings from the locale
            specified in argv[2]. We assign the result of this newlocale()
            call to 'nloc' rather than 'loc', since in some cases, we might
            want to preserve 'loc' if this call fails. */
         if (argc > 2) {
             nloc = newlocale(LC_TIME_MASK, argv[2], loc);
             if (nloc == (locale_t) 0)
             loc = nloc;
         /* Apply the newly created locale to this thread */
         /* Test effect of LC_NUMERIC */
         printf("%8.3f\n", 123456.789);
         /* Test effect of LC_TIME */
         t = time(NULL);
         tm = localtime(&t);
         if (tm == NULL)
         s = strftime(buf, sizeof(buf), "%c", tm);
         if (s == 0)
         printf("%s\n", buf);
         /* Free the locale object */
         exit(EXIT_SUCCESS); }


     locale(1),   duplocale(3),   setlocale(3),   uselocale(3),   locale(5),


     This  page  is  part of release 4.16 of the Linux man-pages project.  A
     description of the project, information about reporting bugs,  and  the
     latest     version     of     this    page,    can    be    found    at

Linux 2017-09-15 NEWLOCALE(3)

/data/webs/external/dokuwiki/data/pages/man/freelocale.txt · Last modified: 2019/05/17 09:47 by

Was this page helpful?-11+1

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki