Re: [boost] [filesystem] truncate() function?

Subject: Re: [boost] [filesystem] truncate() function?
From: Gottlob Frege (gottlobfrege_at_[hidden])
Date: 2009-10-15 08:48:30

On 10/15/09, OvermindDL1 <overminddl1_at_[hidden]> wrote:
> On Wed, Oct 14, 2009 at 10:36 PM, Jonathan Franklin
> <franklin.jonathan_at_[hidden]> wrote:
>> On Wed, Oct 14, 2009 at 8:59 PM, Gottlob Frege <gottlobfrege_at_[hidden]>
>> wrote:
>>> It may be beyond the scope of Boost.Filesystem, but I'd really prefer
>>> C++ exceptions to be thrown instead of SIG faults.  Particularly if
>>> I'm trying to write x-platform code, which might very well be the
>>> reason I'm using Boost.Filesystem instead of direct OS calls in the
>>> first place.
>>
>> I'm pretty sure that the C and C++ lib calls that write to a file will
>> result in your app being terminated as a result of the signal in
>> question when the file being written exceeds the max size.
>>
>> It's been a *long* time since I've written any posix signal handlers,
>> but I think you're going to run into control flow problems if you try
>> to convert this signal to a c++ exception. <cue expert commentary
>> here>
>
> Actually you could probably just set a global volatile boolean, and
> return from the signal handler as normal.  Then test for that boolean
> in the wrapper code, if true then set to false then throw the
> exception, else return.
>

Unfortunately, that is not threadsafe. But I do think it is doable.
Just probably beyond Boost.Filesystem. Maybe a separate library.

Tony