newlocale(3)



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

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

SYNOPSIS
       #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:
                  _GNU_SOURCE

DESCRIPTION
       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
       constants LC_ADDRESS_MASK, LC_CTYPE_MASK, LC_COLLATE_MASK, LC_IDENTIFI-
       CATION_MASK, LC_MEASUREMENT_MASK,  LC_MESSAGES_MASK,  LC_MONETARY_MASK,
       LC_NUMERIC_MASK,  LC_NAME_MASK,  LC_PAPER_MASK,  LC_TELEPHONE_MASK, and
       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:

       "POSIX"
              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
              locale(7)).

   freelocale()
       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.

RETURN VALUE
       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.

ERRORS
       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.

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

CONFORMING TO
       POSIX.1-2008.

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

EXAMPLE
       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]);
               exit(EXIT_FAILURE);
           }

           /* 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)
               errExit("newlocale");

           /* 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)
                   errExit("newlocale");
               loc = nloc;
           }

           /* Apply the newly created locale to this thread */

           uselocale(loc);

           /* 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)
               errExit("time");

           s = strftime(buf, sizeof(buf), "%c", tm);
           if (s == 0)
               errExit("strftime");

           printf("%s\n", buf);

           /* Free the locale object */

           freelocale(loc);

           exit(EXIT_SUCCESS);
       }

SEE ALSO
       locale(1),   duplocale(3),   setlocale(3),   uselocale(3),   locale(5),
       locale(7)

COLOPHON
       This  page  is  part of release 4.13 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
       https://www.kernel.org/doc/man-pages/.

Linux                             2017-09-15                      NEWLOCALE(3)

Man(1) output converted with man2html
list of all man pages