Reading unicode file in c

int main()
{
        FILE *ptr_file;
        char buf[1000];

        ptr_file =fopen("input.txt","r");
        if (!ptr_file)
            return 1;

        while (fgets(buf,1000, ptr_file)!=NULL)
            printf("%s",buf);

    fclose(ptr_file);
        return 0;
}