1nl_langinfo(3) Library Functions Manual nl_langinfo(3)
2
6 nl_langinfo, nl_langinfo_l - query language and locale information
7
9 Standard C library (libc, -lc)
10
12 #include <langinfo.h>
13 char *nl_langinfo(nl_item item);
15 char *nl_langinfo_l(nl_item item, locale_t locale);
16 Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
18 nl_langinfo_l():
20 Since glibc 2.24:
21 _POSIX_C_SOURCE >= 200809L
22 glibc 2.23 and earlier:
23 _POSIX_C_SOURCE >= 200112L
24
26 The nl_langinfo() and nl_langinfo_l() functions provide access to lo‐
27 cale information in a more flexible way than localeconv(3). nl_lang‐
28 info() returns a string which is the value corresponding to item in the
29 program's current global locale. nl_langinfo_l() returns a string
30 which is the value corresponding to item for the locale identified by
31 the locale object locale, which was previously created by newlocale(3).
32 Individual and additional elements of the locale categories can be
33 queried.
34 Examples for the locale elements that can be specified in item using
36 the constants defined in <langinfo.h> are:
37 CODESET (LC_CTYPE)
39 Return a string with the name of the character encoding used in
40 the selected locale, such as "UTF-8", "ISO-8859-1", or
41 "ANSI_X3.4-1968" (better known as US-ASCII). This is the same
42 string that you get with "locale charmap". For a list of char‐
43 acter encoding names, try "locale -m" (see locale(1)).
44 D_T_FMT (LC_TIME)
46 Return a string that can be used as a format string for strf‐
47 time(3) to represent time and date in a locale-specific way (%c
48 conversion specification).
49 D_FMT (LC_TIME)
51 Return a string that can be used as a format string for strf‐
52 time(3) to represent a date in a locale-specific way (%x conver‐
53 sion specification).
54 T_FMT (LC_TIME)
56 Return a string that can be used as a format string for strf‐
57 time(3) to represent a time in a locale-specific way (%X conver‐
58 sion specification).
59 AM_STR (LC_TIME)
61 Return a string that represents affix for ante meridiem (before
62 noon, "AM") time. (Used in %p strftime(3) conversion specifica‐
63 tion.)
64 PM_STR (LC_TIME)
66 Return a string that represents affix for post meridiem (before
67 midnight, "PM") time. (Used in %p strftime(3) conversion speci‐
68 fication.)
69 T_FMT_AMPM (LC_TIME)
71 Return a string that can be used as a format string for strf‐
72 time(3) to represent a time in a.m. or p.m. notation in a lo‐
73 cale-specific way (%r conversion specification).
74 ERA (LC_TIME)
76 Return era description, which contains information about how
77 years are counted and displayed for each era in a locale. Each
78 era description segment shall have the format:
79 direction:offset:start_date:end_date:era_name:era_format
81 according to the definitions below:
83 direction Either a "+" or a "-" character. The "+" means that
85 years increase from the start_date towards the
86 end_date, "-" means the opposite.
87 offset The epoch year of the start_date.
89 start_date A date in the form yyyy/mm/dd, where yyyy, mm, and
91 dd are the year, month, and day numbers respectively
92 of the start of the era.
93 end_date The ending date of the era, in the same format as
95 the start_date, or one of the two special values
96 "-*" (minus infinity) or "+*" (plus infinity).
97 era_name The name of the era, corresponding to the %EC strf‐
99 time(3) conversion specification.
100 era_format The format of the year in the era, corresponding to
102 the %EY strftime(3) conversion specification.
103 Era description segments are separated by semicolons. Most lo‐
105 cales do not define this value. Examples of locales that do de‐
106 fine this value are the Japanese and Thai locales.
107 ERA_D_T_FMT (LC_TIME)
109 Return a string that can be used as a format string for strf‐
110 time(3) for alternative representation of time and date in a lo‐
111 cale-specific way (%Ec conversion specification).
112 ERA_D_FMT (LC_TIME)
114 Return a string that can be used as a format string for strf‐
115 time(3) for alternative representation of a date in a locale-
116 specific way (%Ex conversion specification).
117 ERA_T_FMT (LC_TIME)
119 Return a string that can be used as a format string for strf‐
120 time(3) for alternative representation of a time in a locale-
121 specific way (%EX conversion specification).
122 DAY_{1–7} (LC_TIME)
124 Return name of the n-th day of the week. [Warning: this follows
125 the US convention DAY_1 = Sunday, not the international conven‐
126 tion (ISO 8601) that Monday is the first day of the week.]
127 (Used in %A strftime(3) conversion specification.)
128 ABDAY_{1–7} (LC_TIME)
130 Return abbreviated name of the n-th day of the week. (Used in
131 %a strftime(3) conversion specification.)
132 MON_{1–12} (LC_TIME)
134 Return name of the n-th month. (Used in %B strftime(3) conver‐
135 sion specification.)
136 ABMON_{1–12} (LC_TIME)
138 Return abbreviated name of the n-th month. (Used in %b strf‐
139 time(3) conversion specification.)
140 RADIXCHAR (LC_NUMERIC)
142 Return radix character (decimal dot, decimal comma, etc.).
143 THOUSEP (LC_NUMERIC)
145 Return separator character for thousands (groups of three dig‐
146 its).
147 YESEXPR (LC_MESSAGES)
149 Return a regular expression that can be used with the regex(3)
150 function to recognize a positive response to a yes/no question.
151 NOEXPR (LC_MESSAGES)
153 Return a regular expression that can be used with the regex(3)
154 function to recognize a negative response to a yes/no question.
155 CRNCYSTR (LC_MONETARY)
157 Return the currency symbol, preceded by "-" if the symbol should
158 appear before the value, "+" if the symbol should appear after
159 the value, or "." if the symbol should replace the radix charac‐
160 ter.
161 The above list covers just some examples of items that can be re‐
163 quested. For a more detailed list, consult The GNU C Library Reference
164 Manual.
165
167 On success, these functions return a pointer to a string which is the
168 value corresponding to item in the specified locale.
169 If no locale has been selected by setlocale(3) for the appropriate cat‐
171 egory, nl_langinfo() return a pointer to the corresponding string in
172 the "C" locale. The same is true of nl_langinfo_l() if locale speci‐
173 fies a locale where langinfo data is not defined.
174 If item is not valid, a pointer to an empty string is returned.
176 The pointer returned by these functions may point to static data that
178 may be overwritten, or the pointer itself may be invalidated, by a sub‐
179 sequent call to nl_langinfo(), nl_langinfo_l(), or setlocale(3). The
180 same statements apply to nl_langinfo_l() if the locale object referred
181 to by locale is freed or modified by freelocale(3) or newlocale(3).
182 POSIX specifies that the application may not modify the string returned
184 by these functions.
185
187 For an explanation of the terms used in this section, see at‐
188 tributes(7).
189 ┌─────────────────────────────────────┬───────────────┬────────────────┐
191 │Interface │ Attribute │ Value │
192 ├─────────────────────────────────────┼───────────────┼────────────────┤
193 │nl_langinfo() │ Thread safety │ MT-Safe locale │
194 └─────────────────────────────────────┴───────────────┴────────────────┘
195
197 POSIX.1-2008.
198
200 POSIX.1-2001, SUSv2.
201
203 The behavior of nl_langinfo_l() is undefined if locale is the special
204 locale object LC_GLOBAL_LOCALE or is not a valid locale object handle.
205
207 The following program sets the character type and the numeric locale
208 according to the environment and queries the terminal character set and
209 the radix character.
210 #include <langinfo.h>
212 #include <locale.h>
213 #include <stdio.h>
214 #include <stdlib.h>
215 int
217 main(void)
218 {
219 setlocale(LC_CTYPE, "");
220 setlocale(LC_NUMERIC, "");
221 printf("%s\n", nl_langinfo(CODESET));
223 printf("%s\n", nl_langinfo(RADIXCHAR));
224 exit(EXIT_SUCCESS);
226 }
227
229 locale(1), localeconv(3), setlocale(3), charsets(7), locale(7)
230 The GNU C Library Reference Manual
232Linux man-pages 6.04 2023-03-30 nl_langinfo(3)