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PROLOG
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of
this interface may differ (consult the corresponding Linux manual page for details of
Linux behavior), or the interface may not be implemented on Linux.
NAME
langinfo.h — language information constants
SYNOPSIS
#include <langinfo.h>
DESCRIPTION
The <langinfo.h> header shall define the symbolic constants used to identify items of
langinfo data (see nl_langinfo()).
The <langinfo.h> header shall define the locale_t type as described in <locale.h>.
The <langinfo.h> header shall define the nl_item type as described in <nl_types.h>.
The <langinfo.h> header shall define the following symbolic constants with type nl_item.
The entries under Category indicate in which setlocale() category each item is defined.
┌───────────┬───────────┬───────────────────────────────────────────────────────────┐
│ Constant │ Category │ Meaning │
├───────────┼───────────┼───────────────────────────────────────────────────────────┤
│CODESET │LC_CTYPE │Codeset name. │
│D_T_FMT │LC_TIME │String for formatting date and time. │
│D_FMT │LC_TIME │Date format string. │
│T_FMT │LC_TIME │Time format string. │
│T_FMT_AMPM │LC_TIME │a.m. or p.m. time format string. │
│AM_STR │LC_TIME │Ante-meridiem affix. │
│PM_STR │LC_TIME │Post-meridiem affix. │
│DAY_1 │LC_TIME │Name of the first day of the week (for example, Sunday). │
│DAY_2 │LC_TIME │Name of the second day of the week (for example, Monday). │
│DAY_3 │LC_TIME │Name of the third day of the week (for example, Tuesday). │
│DAY_4 │LC_TIME │Name of the fourth day of the week │
│ │ │(for example, Wednesday). │
│DAY_5 │LC_TIME │Name of the fifth day of the week (for example, Thursday). │
│DAY_6 │LC_TIME │Name of the sixth day of the week (for example, Friday). │
│DAY_7 │LC_TIME │Name of the seventh day of the week │
│ │ │(for example, Saturday). │
│ABDAY_1 │LC_TIME │Abbreviated name of the first day of the week. │
│ABDAY_2 │LC_TIME │Abbreviated name of the second day of the week. │
│ABDAY_3 │LC_TIME │Abbreviated name of the third day of the week. │
│ABDAY_4 │LC_TIME │Abbreviated name of the fourth day of the week. │
│ABDAY_5 │LC_TIME │Abbreviated name of the fifth day of the week. │
│ABDAY_6 │LC_TIME │Abbreviated name of the sixth day of the week. │
│ABDAY_7 │LC_TIME │Abbreviated name of the seventh day of the week. │
│MON_1 │LC_TIME │Name of the first month of the year. │
│MON_2 │LC_TIME │Name of the second month. │
│MON_3 │LC_TIME │Name of the third month. │
│MON_4 │LC_TIME │Name of the fourth month. │
│MON_5 │LC_TIME │Name of the fifth month. │
│MON_6 │LC_TIME │Name of the sixth month. │
│MON_7 │LC_TIME │Name of the seventh month. │
│MON_8 │LC_TIME │Name of the eighth month. │
│MON_9 │LC_TIME │Name of the ninth month. │
│MON_10 │LC_TIME │Name of the tenth month. │
│MON_11 │LC_TIME │Name of the eleventh month. │
│MON_12 │LC_TIME │Name of the twelfth month. │
│ABMON_1 │LC_TIME │Abbreviated name of the first month. │
│ABMON_2 │LC_TIME │Abbreviated name of the second month. │
│ABMON_3 │LC_TIME │Abbreviated name of the third month. │
│ABMON_4 │LC_TIME │Abbreviated name of the fourth month. │
│ABMON_5 │LC_TIME │Abbreviated name of the fifth month. │
│ABMON_6 │LC_TIME │Abbreviated name of the sixth month. │
│ABMON_7 │LC_TIME │Abbreviated name of the seventh month. │
│ABMON_8 │LC_TIME │Abbreviated name of the eighth month. │
│ABMON_9 │LC_TIME │Abbreviated name of the ninth month. │
│ABMON_10 │LC_TIME │Abbreviated name of the tenth month. │
│ABMON_11 │LC_TIME │Abbreviated name of the eleventh month. │
│ABMON_12 │LC_TIME │Abbreviated name of the twelfth month. │
│ERA │LC_TIME │Era description segments. │
│ERA_D_FMT │LC_TIME │Era date format string. │
│ERA_D_T_FMT│LC_TIME │Era date and time format string. │
│ERA_T_FMT │LC_TIME │Era time format string. │
│ALT_DIGITS │LC_TIME │Alternative symbols for digits. │
│RADIXCHAR │LC_NUMERIC │Radix character. │
│THOUSEP │LC_NUMERIC │Separator for thousands. │
│YESEXPR │LC_MESSAGES│Affirmative response expression. │
│NOEXPR │LC_MESSAGES│Negative response expression. │
│CRNCYSTR │LC_MONETARY│Local currency symbol, preceded by '-' if the symbol │
│ │ │should appear before the value, '+' if the symbol should │
│ │ │appear after the value, or '.' if the symbol should │
│ │ │replace the radix character. If the local currency symbol │
│ │ │is the empty string, implementations may return the empty │
│ │ │string (""). │
└───────────┴───────────┴───────────────────────────────────────────────────────────┘
If the locale's values for p_cs_precedes and n_cs_precedes do not match, the value of
nl_langinfo(CRNCYSTR) and nl_langinfo_l(CRNCYSTR,loc) is unspecified.
The following shall be declared as a function and may also be defined as a macro. A
function prototype shall be provided.
char *nl_langinfo(nl_item);
char *nl_langinfo_l(nl_item, locale_t);
Inclusion of the <langinfo.h> header may also make visible all symbols from <nl_types.h>.
The following sections are informative.
APPLICATION USAGE
Wherever possible, users are advised to use functions compatible with those in the ISO C
standard to access items of langinfo data. In particular, the strftime() function should
be used to access date and time information defined in category LC_TIME. The localeconv()
function should be used to access information corresponding to RADIXCHAR, THOUSEP, and
CRNCYSTR.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
Chapter 7, Locale, <locale.h>, <nl_types.h>
The System Interfaces volume of POSIX.1‐2017, nl_langinfo(), localeconv(), strfmon(),
strftime()
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1-2017, Standard for Information Technology -- Portable Operating System Interface
(POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by
the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and The Open Group
Standard, the original IEEE and The Open Group Standard is the referee document. The
original Standard can be obtained online at http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear in this page are most likely to have
been introduced during the conversion of the source files to man page format. To report
such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .