langinfo.h - Man Page

language information constants


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.


#include <langinfo.h>


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.

D_T_FMTLC_TIMEString for formatting date and time.
D_FMTLC_TIMEDate format string.
T_FMTLC_TIMETime format string.
T_FMT_AMPMLC_TIMEa.m. or p.m. time format string.
AM_STRLC_TIMEAnte-meridiem affix.
PM_STRLC_TIMEPost-meridiem affix.
DAY_1LC_TIMEName of the first day of the week (for example, Sunday).
DAY_2LC_TIMEName of the second day of the week (for example, Monday).
DAY_3LC_TIMEName of the third day of the week (for example, Tuesday).
DAY_4LC_TIMEName of the fourth day of the week
(for example, Wednesday).
DAY_5LC_TIMEName of the fifth day of the week (for example, Thursday).
DAY_6LC_TIMEName of the sixth day of the week (for example, Friday).
DAY_7LC_TIMEName of the seventh day of the week
(for example, Saturday).
ABDAY_1LC_TIMEAbbreviated name of the first day of the week.
ABDAY_2LC_TIMEAbbreviated name of the second day of the week.
ABDAY_3LC_TIMEAbbreviated name of the third day of the week.
ABDAY_4LC_TIMEAbbreviated name of the fourth day of the week.
ABDAY_5LC_TIMEAbbreviated name of the fifth day of the week.
ABDAY_6LC_TIMEAbbreviated name of the sixth day of the week.
ABDAY_7LC_TIMEAbbreviated name of the seventh day of the week.
MON_1LC_TIMEName of the first month of the year.
MON_2LC_TIMEName of the second month.
MON_3LC_TIMEName of the third month.
MON_4LC_TIMEName of the fourth month.
MON_5LC_TIMEName of the fifth month.
MON_6LC_TIMEName of the sixth month.
MON_7LC_TIMEName of the seventh month.
MON_8LC_TIMEName of the eighth month.
MON_9LC_TIMEName of the ninth month.
MON_10LC_TIMEName of the tenth month.
MON_11LC_TIMEName of the eleventh month.
MON_12LC_TIMEName of the twelfth month.
ABMON_1LC_TIMEAbbreviated name of the first month.
ABMON_2LC_TIMEAbbreviated name of the second month.
ABMON_3LC_TIMEAbbreviated name of the third month.
ABMON_4LC_TIMEAbbreviated name of the fourth month.
ABMON_5LC_TIMEAbbreviated name of the fifth month.
ABMON_6LC_TIMEAbbreviated name of the sixth month.
ABMON_7LC_TIMEAbbreviated name of the seventh month.
ABMON_8LC_TIMEAbbreviated name of the eighth month.
ABMON_9LC_TIMEAbbreviated name of the ninth month.
ABMON_10LC_TIMEAbbreviated name of the tenth month.
ABMON_11LC_TIMEAbbreviated name of the eleventh month.
ABMON_12LC_TIMEAbbreviated name of the twelfth month.
ERALC_TIMEEra description segments.
ERA_D_FMTLC_TIMEEra date format string.
ERA_D_T_FMTLC_TIMEEra date and time format string.
ERA_T_FMTLC_TIMEEra time format string.
ALT_DIGITSLC_TIMEAlternative symbols for digits.
THOUSEPLC_NUMERICSeparator for thousands.
YESEXPRLC_MESSAGESAffirmative response expression.
NOEXPRLC_MESSAGESNegative response expression.
CRNCYSTRLC_MONETARYLocal 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.



Future Directions


See Also

Chapter 7, Locale, <locale.h>, <nl_types.h>

The System Interfaces volume of POSIX.1-2017, nl_langinfo(), localeconv(), strfmon(), strftime()

Referenced By

fscanf(3p), localeconv(3p), nl_langinfo(3p), nl_types.h(0p), setlocale(3p).

2017 IEEE/The Open Group POSIX Programmer's Manual