Re: Why does close_stdout close stdout and stderr?

[Paul Eggert <eggert@cs.ucla.edu>]

Kamil Dudka wrote:

>> OK, but this shouldn't be a problem with any applications currently
>> using close_stdout. At least, none of the applications I know about.
> 
> How would you know if they did?

The usual way: ordinary users would be complaining. By "ordinary users" I mean 
users other than developers who are employing unusual compiler options, 
LD_PRELOAD settings, etc. for testing.
> As long as you link libraries dynamically, any of the directly or indirectly
> linked libraries can introduce an ELF destructor or atexit() handler anytime,

I don't see any way around this problem in general with the closeout module's 
current API, because when it discovers an I/O error it calls _exit, and _exit 
also clashes with that kind of cleanup handling.

If we want Coreutils and similar programs to be robust even for developers with 
unusual configurations for testing, I expect we'll need to change the programs 
to not use the closeout module at all. This would complicate these programs, 
since we'd need to check every way that every stdin-reading or stdout- or 
stderr-writing program can exit normally, and modify the affected programs to 
check the relevant I/O streams just before the normal exit occurs.