1NL_LANGINFO(3) Linux Programmer's Manual NL_LANGINFO(3)
2
6 nl_langinfo, nl_langinfo_l - query language and locale information
7
9 #include <langinfo.h>
10 char *nl_langinfo(nl_item item);
12 char *nl_langinfo_l(nl_item item, locale_t locale);
13 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
15 nl_langinfo_l():
17 Since glibc 2.24:
18 _POSIX_C_SOURCE >= 200809L
19 Glibc 2.23 and earlier:
20 _POSIX_C_SOURCE >= 200112L
21
23 The nl_langinfo() and nl_langinfo_l() functions provide access to lo‐
24 cale information in a more flexible way than localeconv(3). nl_lang‐
25 info() returns a string which is the value corresponding to item in the
26 program's current global locale. nl_langinfo_l() returns a string
27 which is the value corresponding to item for the locale identified by
28 the locale object locale, which was previously created by newlocale(3).
29 Individual and additional elements of the locale categories can be
30 queried.
31 Examples for the locale elements that can be specified in item using
33 the constants defined in <langinfo.h> are:
34 CODESET (LC_CTYPE)
36 Return a string with the name of the character encoding used in
37 the selected locale, such as "UTF-8", "ISO-8859-1", or
38 "ANSI_X3.4-1968" (better known as US-ASCII). This is the same
39 string that you get with "locale charmap". For a list of char‐
40 acter encoding names, try "locale -m" (see locale(1)).
41 D_T_FMT (LC_TIME)
43 Return a string that can be used as a format string for strf‐
44 time(3) to represent time and date in a locale-specific way (%c
45 conversion specification).
46 D_FMT (LC_TIME)
48 Return a string that can be used as a format string for strf‐
49 time(3) to represent a date in a locale-specific way (%x conver‐
50 sion specification).
51 T_FMT (LC_TIME)
53 Return a string that can be used as a format string for strf‐
54 time(3) to represent a time in a locale-specific way (%X conver‐
55 sion specification).
56 AM_STR (LC_TIME)
58 Return a string that represents affix for ante meridiem (before
59 noon, "AM") time. (Used in %p strftime(3) conversion specifica‐
60 tion.)
61 PM_STR (LC_TIME)
63 Return a string that represents affix for post meridiem (before
64 midnight, "PM") time. (Used in %p strftime(3) conversion speci‐
65 fication.)
66 T_FMT_AMPM (LC_TIME)
68 Return a string that can be used as a format string for strf‐
69 time(3) to represent a time in a.m. or p.m. notation a locale-
70 specific way (%r conversion specification).
71 ERA (LC_TIME)
73 Return era description, which contains information about how
74 years are counted and displayed for each era in a locale. Each
75 era description segment shall have the format:
76 direction:offset:start_date:end_date:era_name:era_format
78 according to the definitions below:
80 direction Either a "+" or a "-" character. The "+" means that
82 years increase from the start_date towards the
83 end_date, "-" means the opposite.
84 offset The epoch year of the start_date.
86 start_date A date in the form yyyy/mm/dd, where yyyy, mm, and
88 dd are the year, month, and day numbers respectively
89 of the start of the era.
90 end_date The ending date of the era, in the same format as
92 the start_date, or one of the two special values
93 "-*" (minus infinity) or "+*" (plus infinity).
94 era_name The name of the era, corresponding to the %EC strf‐
96 time(3) conversion specification.
97 era_format The format of the year in the era, corresponding to
99 the %EY strftime(3) conversion specification.
100 Era description segments are separated by semicolons. Most lo‐
102 cales do not define this value. Examples of locales that do de‐
103 fine this value are the Japanese and Thai locales.
104 ERA_D_T_FMT (LC_TIME)
106 Return a string that can be used as a format string for strf‐
107 time(3) for alternative representation of time and date in a lo‐
108 cale-specific way (%Ec conversion specification).
109 ERA_D_FMT (LC_TIME)
111 Return a string that can be used as a format string for strf‐
112 time(3) for alternative representation of a date in a locale-
113 specific way (%Ex conversion specification).
114 ERA_T_FMT (LC_TIME)
116 Return a string that can be used as a format string for strf‐
117 time(3) for alternative representation of a time in a locale-
118 specific way (%EX conversion specification).
119 DAY_{1–7} (LC_TIME)
121 Return name of the n-th day of the week. [Warning: this follows
122 the US convention DAY_1 = Sunday, not the international conven‐
123 tion (ISO 8601) that Monday is the first day of the week.]
124 (Used in %A strftime(3) conversion specification.)
125 ABDAY_{1–7} (LC_TIME)
127 Return abbreviated name of the n-th day of the week. (Used in
128 %a strftime(3) conversion specification.)
129 MON_{1–12} (LC_TIME)
131 Return name of the n-th month. (Used in %B strftime(3) conver‐
132 sion specification.)
133 ABMON_{1–12} (LC_TIME)
135 Return abbreviated name of the n-th month. (Used in %b strf‐
136 time(3) conversion specification.)
137 RADIXCHAR (LC_NUMERIC)
139 Return radix character (decimal dot, decimal comma, etc.).
140 THOUSEP (LC_NUMERIC)
142 Return separator character for thousands (groups of three dig‐
143 its).
144 YESEXPR (LC_MESSAGES)
146 Return a regular expression that can be used with the regex(3)
147 function to recognize a positive response to a yes/no question.
148 NOEXPR (LC_MESSAGES)
150 Return a regular expression that can be used with the regex(3)
151 function to recognize a negative response to a yes/no question.
152 CRNCYSTR (LC_MONETARY)
154 Return the currency symbol, preceded by "-" if the symbol should
155 appear before the value, "+" if the symbol should appear after
156 the value, or "." if the symbol should replace the radix charac‐
157 ter.
158 The above list covers just some examples of items that can be re‐
160 quested. For a more detailed list, consult The GNU C Library Reference
161 Manual.
162
164 On success, these functions return a pointer to a string which is the
165 value corresponding to item in the specified locale.
166 If no locale has been selected by setlocale(3) for the appropriate cat‐
168 egory, nl_langinfo() return a pointer to the corresponding string in
169 the "C" locale. The same is true of nl_langinfo_l() if locale speci‐
170 fies a locale where langinfo data is not defined.
171 If item is not valid, a pointer to an empty string is returned.
173 The pointer returned by these functions may point to static data that
175 may be overwritten, or the pointer itself may be invalidated, by a sub‐
176 sequent call to nl_langinfo(), nl_langinfo_l(), or setlocale(3). The
177 same statements apply to nl_langinfo_l() if the locale object referred
178 to by locale is freed or modified by freelocale(3) or newlocale(3).
179 POSIX specifies that the application may not modify the string returned
181 by these functions.
182
184 For an explanation of the terms used in this section, see at‐
185 tributes(7).
186 ┌─────────────────────────────────────┬───────────────┬────────────────┐
188 │Interface │ Attribute │ Value │
189 ├─────────────────────────────────────┼───────────────┼────────────────┤
190 │nl_langinfo() │ Thread safety │ MT-Safe locale │
191 └─────────────────────────────────────┴───────────────┴────────────────┘
192
194 POSIX.1-2001, POSIX.1-2008, SUSv2.
195
197 The behavior of nl_langinfo_l() is undefined if locale is the special
198 locale object LC_GLOBAL_LOCALE or is not a valid locale object handle.
199
201 The following program sets the character type and the numeric locale
202 according to the environment and queries the terminal character set and
203 the radix character.
204 #include <langinfo.h>
206 #include <locale.h>
207 #include <stdio.h>
208 #include <stdlib.h>
209 int
211 main(int argc, char *argv[])
212 {
213 setlocale(LC_CTYPE, "");
214 setlocale(LC_NUMERIC, "");
215 printf("%s\n", nl_langinfo(CODESET));
217 printf("%s\n", nl_langinfo(RADIXCHAR));
218 exit(EXIT_SUCCESS);
220 }
221
223 locale(1), localeconv(3), setlocale(3), charsets(7), locale(7)
224 The GNU C Library Reference Manual
226
228 This page is part of release 5.12 of the Linux man-pages project. A
229 description of the project, information about reporting bugs, and the
230 latest version of this page, can be found at
231 https://www.kernel.org/doc/man-pages/.
232GNU 2021-03-22 NL_LANGINFO(3)