Question

My C program is pasted below. In bash, the program print “char is “, Ω
is not printed. My locale are all en_US.utf8.

#include <stdio.h>
#include <wchar.h>
#include <stdlib.h>

int main() {
   int r;
   wchar_t myChar1 = L'Ω';
   r = wprintf(L"char is %c\n", myChar1);
}

Answer 1

This was quite interesting. Apparently the compiler translates the omega from UTF-8 to UNICODE but somehow the libc messes it up.

First of all: the %c-format specifier expects a char (even in the wprintf-version) so you have to specify %lc (and therefore %ls for strings).

Secondly if you run your code like that the locale is set to C (it isn’t automatically taken from the environment). You have to call setlocale with an empty string to take the locale from the environment, so the libc is happy again.

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

int main() {
    int r;
    wchar_t myChar1 = L'Ω';
    setlocale(LC_CTYPE, "");
    r = wprintf(L"char is %lc (%x)\n", myChar1, myChar1);
}