duplocale — duplicate a locale object
The duplocale() function shall create a duplicate copy of the locale object referenced by the locobj argument.
If the locobj argument is LC_GLOBAL_LOCALE, duplocale() shall create a new locale object containing a copy of the global locale determined by the setlocale() function.
The behavior is undefined if the locobj argument is not a valid locale object handle.
Upon successful completion, the duplocale() function shall return a handle for a new locale object. Otherwise, duplocale() shall return (locale_t)0 and set errno to indicate the error.
The duplocale() function shall fail if:
- [ENOMEM]
- There is not enough memory available to create the locale object or load the locale data.
Constructing an Altered Version of an Existing Locale Object
The following example shows a code fragment to create a slightly altered version of an existing locale object. The function takes a locale object and a locale name and it replaces the LC_TIME category data in the locale object with that from the named locale.
#include <locale.h> ...
locale_t with_changed_lc_time (locale_t obj, const char *name) {
locale_t retval = duplocale (obj); if (retval != (locale_t) 0) { locale_t changed = newlocale (LC_TIME_MASK, name, retval); if (changed == (locale_t) 0) /* An error occurred. Free all allocated resources. */ freelocale (retval); retval = changed; } return retval; }
The use of the duplocale() function is recommended for situations where a locale object is being used in multiple places, and it is possible that the lifetime of the locale object might end before all uses are finished. Another reason to duplicate a locale object is if a slightly modified form is needed. This can be achieved by a call to newlocale() following the duplocale() call.
As with the newlocale() function, handles for locale objects created by the duplocale() function should be released by a corresponding call to freelocale().
The duplocale() function can also be used in conjunction with uselocale((locale_t)0). This returns the locale in effect for the calling thread, but can have the value LC_GLOBAL_LOCALE. Passing LC_GLOBAL_LOCALE to functions such as isalnum_l() results in undefined behavior, but applications can convert it into a usable locale object by using duplocale().
None.
None.
freelocale , newlocale , uselocale
XBD <locale.h>
First released in Issue 7.
POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0077 [283,301], XSH/TC1-2008/0078 [283], and XSH/TC1-2008/0079 [301] are applied.
POSIX.1-2008, Technical Corrigendum 2, XSH/TC2-2008/0084 [753] is applied.
return to top of page