Re: [Bug-glpk] [Fwd: glpsol's --write format changed]

[Heinrich Schuchardt]

Hello Andrew,

It would help if glpsol --write would write a format version descriptor
into the first line. Then a reading program can easily check if it can
parse the file.

E.g.
c File-Format: GLPK MIP 1.0

Best regards

Heinrich Schuchardt

On 01/21/2017 02:37 PM, Andrew Makhorin wrote:
>> -------- Forwarded Message --------
>> From: Morten Welinder <address@hidden>
>> To: address@hidden
>> Subject: glpsol's --write format changed
>> Date: Fri, 20 Jan 2017 08:18:55 -0500
>>
>> It looks like the format for "glpsol --write ..." changed in Glpk
>> version 4.59, a version
>> described as a maintenance release.
>>
>> I realise that this was probably deliberate.  Nevertheless, I would
>> like you to think of
>> it as a bug.
>>
>> The effect of such a change is to break programs that interact with
>> glpsol.  In my case,
>> Gnumeric broke when some Linux distribution upgraded Glpk.
>>
>> Please keep such interactions in mind for future format changes.
>>
>> I note that neither the new format nor the old one contains any format
>> version indication.
>> Detection of format is thus inherently an ad hoc affair.
>>
>> Morten Welinder
>> Gnumeric maintainer
>>
>>
> 
> Thank you for your bug report.
> 
> In my defence I'd like to note that it is quite difficult to design
> all aspects of the interface at once. The old format was chosen
> temporarily just to provide functionality of write_sol and subsequent
> read_sol, and there was no intention to use this old format for
> communication between glpk and other application programs. Starting
> from glpk 4.60 all api routines use so called "glpk format" (which is
> a thoroughly designed unified plain text format based on dimacs format),
> and I have no plans to change this format in the future.
> 
> 
> Andrew Makhorin,
> the author and maintainer of glpk
> 
> 
> 
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