nl_langinfo − query language and locale information


#include <langinfo.h>

char *nl_langinfo(nl_item item);


The nl_langinfo() function provides access to locale information in a more flexible way than localeconv(3) does. Individual and additional elements of the locale categories can be queried.

Examples for the locale elements that can be specified in item using the constants defined in <langinfo.h> are:

Return a string with the name of the character encoding used in the selected locale, such as "UTF-8", "ISO-8859-1", or "ANSI_X3.4-1968" (better known as US-ASCII). This is the same string that you get with "locale charmap". For a list of character encoding names, try "locale −m", cf. locale(1).


Return a string that can be used as a format string for strftime(3) to represent time and date in a locale-specific way.


Return a string that can be used as a format string for strftime(3) to represent a date in a locale-specific way.


Return a string that can be used as a format string for strftime(3) to represent a time in a locale-specific way.

DAY_{1–7} (LC_TIME)

Return name of the n-th day of the week. [Warning: this follows the US convention DAY_1 = Sunday, not the international convention (ISO 8601) that Monday is the first day of the week.]


Return abbreviated name of the n-th day of the week.

MON_{1–12} (LC_TIME)

Return name of the n-th month.

ABMON_{1–12} (LC_TIME)

Return abbreviated name of the n-th month.


Return radix character (decimal dot, decimal comma, etc.).


Return separator character for thousands (groups of three digits).


Return a regular expression that can be used with the regex(3) function to recognize a positive response to a yes/no question.


Return a regular expression that can be used with the regex(3) function to recognize a negative response to a yes/no question.


Return the 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.

The above list covers just some examples of items that can be requested. For a more detailed list, consult The GNU C Library Reference Manual.


If no locale has been selected by setlocale(3) for the appropriate category, nl_langinfo() returns a pointer to the corresponding string in the "C" locale.

If item is not valid, a pointer to an empty string is returned.

This pointer may point to static data that may be overwritten on the next call to nl_langinfo() or setlocale(3).


SUSv2, POSIX.1-2001.


The following program sets the character type and the numeric locale according to the environment and queries the terminal character set and the radix character.

#include <langinfo.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>

main(int argc, char *argv[])
setlocale(LC_CTYPE, "");
setlocale(LC_NUMERIC, "");
printf("%s\n", nl_langinfo(CODESET));
printf("%s\n", nl_langinfo(RADIXCHAR));


locale(1), localeconv(3), setlocale(3), charsets(7), locale(7)
The GNU C Library Reference Manual


This page is part of release 3.69 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at−pages/.


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.