Re: In GNAT/Ada95(main) use a C-Program

["David C. Hoos, Sr." <david.c.hoos.sr@ada95.com>]

Gerhard Griessnig <grie@sbox.tu-graz.ac.at> wrote in message
news:375EB748.2ABAAC25@sbox.tu-graz.ac.at...
> Thanks for your response,
> we have also read the GNAT-Users Guide.
> We know how to compile-bind and link C-Programes, but we do not know the
Syntax
> how
> to call a C-Program in an Ada-Main-Program and deliver some Parameters.
> We would need some examples ( Syntax ).
>
If by calling a C-Program, you mean invoking a sepaate executable process,
then the answer doesn't depend at all on the language in which it is
written.
To invoke another process in a subshell, one can use an Ada interface to
the library function "system", exactly as is done in a C program.

one way to provide this interface is with the following library
function:

with Interfaces.C;
function Execute_Shell_Command (The_Command_String : String)
      return Interfaces.C.Int is
   package C renames Interfaces.C;
   function System (S : C.Char_Array) return C.Int;
   pragma Import (C, System, "system");
begin
   return System (C.To_C (The_Command_String));
end Execute_Shell_Command;

Then, for example, to display the contents of the current directory,
you would have the following:

with Execute_Shell_Command;
.
.
.
.
Execute_Shell_command ("ls -l");
.
.
.
Read the man page for system, to get additional details such as
what values is returned by the function, etc.

If, instead of executing in a subshell, and waiting for the shell to
terminate, you want your program to spawn a child process, then
for the Sun platform I would recommend using the Posix Ada bindings
from Florida State University, called Florist, available from
http://www.cs.fsu.edu/~baker/ftp/pub/PART/FLORIST/florist990327.tar.gz
ftp://ftp.cs.fsu.edu/pub/PART/FLORIST/florist990327.tar.gz

Look at the services provided by the packaghe POSIX.Process_Primitives.

> About our platform: We use  a Sun-Workstation,  more details follow.
>
> Bye,
>         Gerhard, Peter
>
>
>
>
> David C. Hoos, Sr. schrieb:
>
> > Gerhard Griessnig wrote in message
<375E60AD.C56EAE59@sbox.tu-graz.ac.at>...
> > >Hello,
> > >we want to bind  C-Programs in  a GNAT-Ada95 Mainprogram.
> > >How is it possible, and who is able to send us some examples.
> > >
> > >We need this
> > >        - to communicate with a RS232
> > >                ( are protocols in GNAT-Ada available ? )
> > >        - to communicate with radar
> > >to our roboter (Khepera on Unix).
> > >
> > The RS-232 portion of your question is dependent of the OS/hardware
> > platform.  Can you provide more details?  I have written some
> > serial port communication stuff for Linux/PC and Win32.
> >
> > For the binding of C to Ada, how about reading the
> > Gnat User's Guide, especially the section titled
> > Mixed Language Programming
>