/*
http://cygwin.com/1.7/cygwin-ug-net/ov-new1.7.html#ov-new1.7-posix
- A lot of character sets are supported now via a call to setlocale().
  The setting of the environment variables $LANG, $LC_ALL or $LC_CTYPE will
  be used.  For instance, setting $LANG to "de_DE.ISO-8859-15" before
  starting a Cygwin session will use the ISO-8859-15 character set in
  the entire session.  UTF-8 is supported as well, as in "en_US.UTF-8".
*/

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

void setlocale_test() {
    char * const lc_all = getenv("LC_ALL");
    char * const lang   = getenv("LANG");
    char * const cygwin = getenv("CYGWIN");

    if (!setlocale(LC_ALL, "")) {
        printf("setlocale(LC_ALL,\"\") failed\n");
    } else {
        printf("setlocale(LC_ALL,\"\") okay\n");
    }
    printf("with\tLC_ALL = %s\n", lc_all);
    printf("\tLANG = %s\n",   lang);
    printf("\tCYGWIN = %s\n", cygwin);
}

int
main (int argc, char** argv) {
    putenv("LC_ALL=");
    putenv("LANG=");
    putenv("CYGWIN=");
    setlocale_test();
    putenv("LC_ALL=utf-8");
    putenv("LANG=");
    putenv("CYGWIN=");
    setlocale_test();
    putenv("LC_ALL=");
    putenv("LANG=en_US.UTF-8");
    putenv("CYGWIN=");
    setlocale_test();
    putenv("LC_ALL=UTF-8");
    putenv("LANG=");
    putenv("CYGWIN=");
    setlocale_test();
    putenv("LC_ALL=UTF-8");
    putenv("LANG=");
    putenv("CYGWIN=codepage:utf-8");
    setlocale_test();
    putenv("LC_ALL=UTF-8"); /* error */
    putenv("LANG=en_US.UTF-8");
    putenv("CYGWIN=codepage:utf-8");
    setlocale_test();
    putenv("LC_ALL=");
    putenv("LANG=en_US.UTF-8");
    putenv("CYGWIN=codepage:utf-8");
    setlocale_test();
    putenv("LC_ALL=en_US.UTF-8");
    putenv("LANG=");
    putenv("CYGWIN=");
    setlocale_test();
    putenv("LC_ALL=en_US.UTF-8");
    putenv("LANG=en_US.UTF-8");
    putenv("CYGWIN=");
    setlocale_test();
    putenv("LC_ALL=en_US.utf-8"); /* okay on linux! */
    putenv("LANG=");
    putenv("CYGWIN=");
    setlocale_test();
    putenv("LC_ALL=de.UTF-8");
    putenv("LANG=");
    putenv("CYGWIN=");
    setlocale_test();
    putenv("LC_ALL=en_US.utf-8");  /* okay on linux! */
    putenv("LANG=en_US.utf-8");
    putenv("CYGWIN=");
    setlocale_test();
}