Re: Gprolog 1.4 exec/5 does not work under cygwin

>
> Daniel Diaz-3 wrote:
>>      A first remark without looking at details...
>>
>>      The gprolog version you downloaded is a native Windows app. It does
>>      not know nothing about cygwin.
>>      In particular bash or /bin cannot be resolved.
>>      You can try passing 'c:/cygwin/bin/echo abc' to see if it is better.
>>      For instance try:
>>
>>      exec('dir', I,O,E,P), repeat, get_char(O,T), write(T), T =
>> end_of_file, !, wait(P,S).
>>
>>      What do you obtain ?
>>
>
> Interesting, I get this:
>
>
> $ gprolog
> GNU Prolog 1.4.0
> By Daniel Diaz
> Copyright (C) 1999-2011 Daniel Diaz
> | ?- exec('dir', I,O,E,P), repeat, get_char(O,T), write(T),  T =
> end_of_file, !, wait(P,S).
>   Volume in drive C is OS
>   Volume Serial Number is F44F-E564
>
>   Directory of C:\marku\starlog\trunk
>
> 12/12/2011  12:31 PM<DIR>           .
> 12/12/2011  12:31 PM<DIR>           ..
> 13/12/2011  02:13 PM<DIR>           .svn
> 12/12/2011  12:30 PM<DIR>           art
> 12/12/2011  12:31 PM<DIR>           cuda
> 12/12/2011  12:31 PM<DIR>           doc
> ...
>                 0 File(s)              0 bytes
>                31 Dir(s)  314,787,344,384 bytes free
> end_of_file
>
> uncaught exception: error(system_error('No child processes'),wait/2)
> | ?-
>
>
> which shows that the exec is working, but the wait is not (perhaps the child
> process is not being kept around as a zombie until the wait?)
>
>
>>     or
>>     exec('c:/cygwin/bin/echo abc', I,O,E,P), repeat, get_char(O,T),
>> write(T),  T = end_of_file, !, wait(P,S).
>>     What do you obtain ?
>
> Same result.
> I did this twice - the first time with a non-existent executable and the
> second time with the correct path to cygwin echo.
>
>
> $ gprolog
> GNU Prolog 1.4.0
> By Daniel Diaz
> Copyright (C) 1999-2011 Daniel Diaz
> | ?- exec('c:/cygwin/bin/echo abc', I,O,E,P), repeat, get_char(O,T),
> write(T),  T = end_of_file, !, wait(P,S).
> end_of_file
>
> uncaught exception: error(system_error('No child processes'),wait/2)
> | ?- exec('c:/Apps/cygwin/bin/echo abc', I,O,E,P), repeat, get_char(O,T),
> write(T),  T = end_of_file, !, wait(P,S).
> abc
> end_of_file
>
> uncaught exception: error(system_error('No child processes'),wait/2)
> | ?-
>
>
>
>
>>     If you want a pure cygwin app you should download a source .tar.gz
>> package and build it under cygwin.
>
> Yes, I've tried that.  It builds and installs successfully, but I get the
> same problem with wait/2:
>
>
> Mark.Utting@RWS034 /cygdrive/c/Apps/gprolog-1.4.0/src
> $ which gprolog
> /usr/local/bin/gprolog
>
>
> $ gprolog
> GNU Prolog 1.4.0
> By Daniel Diaz
> Copyright (C) 1999-2011 Daniel Diaz
> | ?- exec('dir', I,O,E,P), repeat, get_char(O,T), write(T),  T =
> end_of_file, !, wait(P,S).
>   Volume in drive C is OS
>   Volume Serial Number is F44F-E564
>
>   Directory of C:\Apps\gprolog-1.4.0\src
>
> 14/12/2011  06:01 AM<DIR>           .
> 14/12/2011  06:01 AM<DIR>           ..
> 17/12/2008  02:36 AM             4,131 .indent.pro
> 18/06/1999  05:53 PM             7,832 AUTOCONF-INFO
> 14/12/2011  06:00 AM<DIR>           BipsFD
> 14/12/2011  05:59 AM<DIR>           BipsPl
> ...
>                22 File(s)        414,279 bytes
>                16 Dir(s)  314,768,809,984 bytes free
> end_of_file
>
> uncaught exception: error(system_error('No child processes'),wait/2)
> | ?-
>
>
>> Does the gprolog 1.4.0 wait/2 call work on your Windows machine?
> Ordinary C programs that use exec and wait seem to work fine,
> for example the fork-03.c program here:
> http://www.csl.mtu.edu/cs4411/www/NOTES/process/fork/wait.html  seems to
> produce the expected output.
>
>
> Thanks
> Mark
>
>
>