Re: Confusing "Success" error message

[Andries E. Brouwer]

On Fri, Nov 08, 2019 at 03:50:43PM +0100, Tim Rühsen wrote:

> > so under unusual circumstances datetime_str() can change errno.
> 
> Sure it does - but never to 0 (Success). And that is what the OP is
> reporting.

Also such things happen.

Some system calls or library calls are such that all values
are possible as return value, so that one cannot recognize
failure from a return value like -1 or NULL.
In such cases, proper behaviour is to set errno to 0,
do the call, and examine errno to see whether it has become nonzero.

Andries