Re: [Gnuplot-info] How to ignore "popen failed"?

[Tatsuro M. <tma...@ya...>]

----- Original Message -----
> From: Tatsuro MATSUOKA <tma...@ya...>
> To: theozh <th...@gm...>; gnu...@li...
> Cc: 
> Date: 2017/7/28, Fri 16:38
> Subject: Re: [Gnuplot-info] How to ignore "popen failed"?
> 
> 
> 
> 
> 
> ----- Original Message -----
>>  From: theozh 
>>  To: gnuplot-info
>>  Cc: 
>>  Date: 2017/7/28, Fri 04:42
>>  Subject: Re: [Gnuplot-info] How to ignore "popen failed"?
>> 
>>  Hi Iva,
>>  thank you for this observation.
>>  Yes, I typically start my scripts under wgnuplot.exe, where the original
>>  code terminates when no file is found.
>>  If I start the same code under the gnuplot.exe terminal it works fine!
>> 
>>  Maybe somebody can explain why there is this difference and maybe
>>  whether or how it's possible to make it behave the same under 
> wgnuplot.exe?
>> 
>>  So, for the time being, no need for extra software like awk, cygwin,
>>  Perl, wrapper-Script, ...
>>  Thanks, Theo.
>> 
> 
> What happens you execute the script on wgnuplot_pipes.exe?
> 
> Tatsuro
> 
> 
In windows binary distribution, there is a file named README-Windows.txt
There described 

* wgnuplot.exe:  GUI version and the default gnuplot executable. As of version 5 
  it emulates pipe functionality.
  
* wgnuplot_pipes.exe:  Variant with full pipe functionality at the expense of
  an additional console window.

* gnuplot.exe:  Text (console) mode version of the gnuplot executable with full
  pipe functionality as it is common on other platforms. In contrast to
  wgnuplot.exe, this program can also accept commands on stdin (standard input)
  and print messages on stdout (standard output). It replaces pgnuplot.exe and
  is recommended to be used with 3rd party applications using gnuplot as graph
  engine, like e.g. Octave (www.octave.org).

Perhaps what you met is side effect? of pipe emulation.

I have tried 

flist=system ("dir /B *.dat")
in the folder where no *.dat on wgnuplot_pipes.exe
A message 'File not found' appears in the additional console  and  "popen failed" does not appear.
I have tried on wgnuplot_pipes.exe

I think that workaround at present is to use wgnuplot_pipes.

BTW, please open a bug ticket on 
https://sourceforge.net/p/gnuplot/bugs/

This topic should be discussed there but not gnuplot-info list in my opinion.

Tatsuro 
Tatsuro