Re: UTF-8 output via "echo_wchar" resulting in errno=1 on Mac OS X

[Clemens Ladisch]

Christoph Ender wrote:
> I've noticed that output of non-ASCII chars using a self-compiled ncurses 5.9 
> (the only
> compile-option being --enable-widec) or the MacPorts binary package of 
> ncurses, also in
> version 5.9, results in an errno=1.

>   echo_wchar(&wcval);
>   e2 = errno;

> e2: 1

> does anyone by chance have an idea what might be the cause?

<http://pubs.opengroup.org/onlinepubs/009695399/functions/errno.html>:
| The value of errno shall be defined only after a call to a function
| for which it is explicitly stated to be set [...].  The value of
| errno should only be examined when it is indicated to be valid by
| a function's return value.

<http://pubs.opengroup.org/onlinepubs/007908799/xcurses/echo_wchar.html>:
| RETURN VALUE
|     Upon successful completion, these functions return OK. Otherwise,
|     they return ERR. 
| ERRORS
|     No errors are defined. 

So, to detect errors, you should check for echo_wchar() itself returning
ERR, and even then, the value of errno is not defined.


Regards,
Clemens