1DUPLOCALE(3P) POSIX Programmer's Manual DUPLOCALE(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 duplocale — duplicate a locale object
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15 #include <locale.h>
16 locale_t duplocale(locale_t locobj);
18
20 The duplocale() function shall create a duplicate copy of the locale
21 object referenced by the locobj argument.
22 If the locobj argument is LC_GLOBAL_LOCALE, duplocale() shall create a
24 new locale object containing a copy of the global locale determined by
25 the setlocale() function.
26 The behavior is undefined if the locobj argument is not a valid locale
28 object handle.
29
31 Upon successful completion, the duplocale() function shall return a
32 handle for a new locale object. Otherwise, duplocale() shall return
33 (locale_t)0 and set errno to indicate the error.
34
36 The duplocale() function shall fail if:
37 ENOMEM There is not enough memory available to create the locale object
39 or load the locale data.
40 The following sections are informative.
42
44 Constructing an Altered Version of an Existing Locale Object
45 The following example shows a code fragment to create a slightly
46 altered version of an existing locale object. The function takes a
47 locale object and a locale name and it replaces the LC_TIME category
48 data in the locale object with that from the named locale.
49 #include <locale.h>
52 ...
53 locale_t
55 with_changed_lc_time (locale_t obj, const char *name)
56 {
57 locale_t retval = duplocale (obj);
59 if (retval != (locale_t) 0)
60 {
61 locale_t changed = newlocale (LC_TIME_MASK, name, retval);
62 if (changed == (locale_t) 0)
63 /* An error occurred. Free all allocated resources. */
64 freelocale (retval);
65 retval = changed;
66 }
67 return retval;
68 }
69
71 The use of the duplocale() function is recommended for situations where
72 a locale object is being used in multiple places, and it is possible
73 that the lifetime of the locale object might end before all uses are
74 finished. Another reason to duplicate a locale object is if a slightly
75 modified form is needed. This can be achieved by a call to newlocale()
76 following the duplocale() call.
77 As with the newlocale() function, handles for locale objects created by
79 the duplocale() function should be released by a corresponding call to
80 freelocale().
81 The duplocale() function can also be used in conjunction with uselo‐
83 cale((locale_t)0). This returns the locale in effect for the calling
84 thread, but can have the value LC_GLOBAL_LOCALE. Passing
85 LC_GLOBAL_LOCALE to functions such as isalnum_l() results in undefined
86 behavior, but applications can convert it into a usable locale object
87 by using duplocale().
88
90 None.
91
93 None.
94
96 freelocale(), newlocale(), uselocale()
97 The Base Definitions volume of POSIX.1‐2017, <locale.h>
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101 Portions of this text are reprinted and reproduced in electronic form
102 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
103 table Operating System Interface (POSIX), The Open Group Base Specifi‐
104 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
105 Electrical and Electronics Engineers, Inc and The Open Group. In the
106 event of any discrepancy between this version and the original IEEE and
107 The Open Group Standard, the original IEEE and The Open Group Standard
108 is the referee document. The original Standard can be obtained online
109 at http://www.opengroup.org/unix/online.html .
110 Any typographical or formatting errors that appear in this page are
112 most likely to have been introduced during the conversion of the source
113 files to man page format. To report such errors, see https://www.ker‐
114 nel.org/doc/man-pages/reporting_bugs.html .
115IEEE/The Open Group 2017 DUPLOCALE(3P)