NL_LANGINFO(P) POSIX Programmer's Manual NL_LANGINFO(P)
nl_langinfo - language information
char *nl_langinfo(nl_item item);
The nl_langinfo() function shall return a pointer to a string containing information rele-
vant to the particular language or cultural area defined in the program's locale (see
<langinfo.h>). The manifest constant names and values of item are defined in <lang-
info.h>. For example:
would return a pointer to the string "Dom" if the identified language was Portuguese, and
"Sun" if the identified language was English.
Calls to setlocale() with a category corresponding to the category of item (see <lang-
info.h>), or to the category LC_ALL , may overwrite the array pointed to by the return
The nl_langinfo() function need not be reentrant. A function that is not required to be
reentrant is not required to be thread-safe.
In a locale where langinfo data is not defined, nl_langinfo() shall return a pointer to
the corresponding string in the POSIX locale. In all locales, nl_langinfo() shall return a
pointer to an empty string if item contains an invalid setting.
This pointer may point to static data that may be overwritten on the next call.
No errors are defined.
The following sections are informative.
Getting Date and Time Formatting Information
The following example returns a pointer to a string containing date and time formatting
information, as defined in the LC_TIME category of the current locale.
strftime(datestring, sizeof(datestring), nl_langinfo(D_T_FMT), tm);
The array pointed to by the return value should not be modified by the program, but may be
modified by further calls to nl_langinfo().
setlocale() , the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale,
Portions of this text are reprinted and reproduced in electronic form from IEEE Std
1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System
Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 NL_LANGINFO(P)