NAME | LIBRARY | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | STANDARDS | HISTORY | NOTES | EXAMPLES | SEE ALSO | COLOPHON |
|
|
duplocale(3) Library Functions Manual duplocale(3)
duplocale - duplicate a locale object
Standard C library (libc, -lc)
#include <locale.h> locale_t duplocale(locale_t locobj); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): duplocale(): Since glibc 2.10: _XOPEN_SOURCE >= 700 Before glibc 2.10: _GNU_SOURCE
The duplocale() function creates a duplicate of the locale object referred to by locobj. If locobj is LC_GLOBAL_LOCALE, duplocale() creates a locale object containing a copy of the global locale determined by setlocale(3).
On success, duplocale() returns a handle for the new locale object. On error, it returns (locale_t) 0, and sets errno to indicate the error.
ENOMEM Insufficient memory to create the duplicate locale object.
POSIX.1-2008.
glibc 2.3.
Duplicating a locale can serve the following purposes: • To create a copy of a locale object in which one of more categories are to be modified (using newlocale(3)). • To obtain a handle for the current locale which can used in other functions that employ a locale handle, such as toupper_l(3). This is done by applying duplocale() to the value returned by the following call: loc = uselocale((locale_t) 0); This technique is necessary, because the above uselocale(3) call may return the value LC_GLOBAL_LOCALE, which results in undefined behavior if passed to functions such as toupper_l(3). Calling duplocale() can be used to ensure that the LC_GLOBAL_LOCALE value is converted into a usable locale object. See EXAMPLES, below. Each locale object created by duplocale() should be deallocated using freelocale(3).
The program below uses uselocale(3) and duplocale() to obtain a handle for the current locale which is then passed to toupper_l(3). The program takes one command-line argument, a string of characters that is converted to uppercase and displayed on standard output. An example of its use is the following: $ ./a.out abc ABC Program source #define _XOPEN_SOURCE 700 #include <ctype.h> #include <locale.h> #include <stdio.h> #include <stdlib.h> #define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \ } while (0) int main(int argc, char *argv[]) { locale_t loc, nloc; if (argc != 2) { fprintf(stderr, "Usage: %s string\n", argv[0]); exit(EXIT_FAILURE); } /* This sequence is necessary, because uselocale() might return the value LC_GLOBAL_LOCALE, which can't be passed as an argument to toupper_l(). */ loc = uselocale((locale_t) 0); if (loc == (locale_t) 0) errExit("uselocale"); nloc = duplocale(loc); if (nloc == (locale_t) 0) errExit("duplocale"); for (char *p = argv[1]; *p; p++) putchar(toupper_l(*p, nloc)); printf("\n"); freelocale(nloc); exit(EXIT_SUCCESS); }
freelocale(3), newlocale(3), setlocale(3), uselocale(3), locale(5), locale(7)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.9.1.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2024-06-26. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
[email protected]
Linux man-pages 6.9.1 2024-06-15 duplocale(3)
Pages that refer to this page: isalpha(3), locale_t(3type), newlocale(3), strfmon(3), toupper(3), towlower(3), towupper(3), uselocale(3), locale(7)