LinuxQuestions.org - setlocale() returns NULL

I need to call setlocale to use gettext from my program. The target system where my program will run is busybox based embedded linux. I compiled busybox with enabled locale support.

This is the testing program code:

Code:

#include <libintl.h>

#include <locale.h>

#include <stdio.h>

#include <stdlib.h>



#define PACKAGE "hello"



int main(void)

{

        fprintf(stderr, "setlocale: \"%s\"\n", setlocale(LC_CTYPE, ""));

        fprintf(stderr, "setlocale: \"%s\"\n", setlocale(LC_MESSAGES, ""));

        perror("setlocale");

        

        fprintf(stderr, "bindtextdomain: \"%s\"\n", bindtextdomain(PACKAGE, "locale"));

        fprintf(stderr, "textdomain: \"%s\"\n\n", textdomain(PACKAGE));

        

        fprintf(stderr, gettext("Hello, world!\n"));

        

        return 0;

}

I created the mo file and put it in locale/xx/LC_MESSAGES/ in the program's directory.

On a normal desktop distro it works: "Hello world" is displayed in the correct translated language according to the environment variable LC_MESSAGES. On the target system it does not work. setlocale works only for C and POSIX. For others, even for en_US, it returns NULL and perror prints:
No such file or directory

Of course gettext then always returns only the original version of text.
I noticed it does not work also on Mepis linux on my desktop PC, although I have the locale packages installed. So I think this is probably not related to busybox/embedded linux

What I am supposed to do to make it work?