Unix Executables

Unix Executables

[Matt Raikes]

Is there a way to call a Unix executable(such as gzip) from within my code.

Re: Unix Executables

[Marin David Condic]

There's always a way. Depends on what exactly you had in mind. If you just
want to invoke a program, here's some code cut from a batch of utilities on
my web page (see: http://www.mcondic.com/):

with Interfaces.C;

procedure UTIL.Perform_System_Command (
    Command     : in     String ;
    Wait        : in     Boolean := True ;
    Success     :    out Boolean) is
    --
    Return_Code : Integer ;
    --
    function Sys (
        Item    : in     Interfaces.C.Char_Array) return Integer ;
    pragma Import (C, Sys, "system") ;
    --
    package C renames Interfaces.C ;
    --
begin
    --
    if (Wait) then
        Return_Code := Sys (
            Item    => C.To_C ("ksh -c " & '"' & Command & '"'));
    else
        Return_Code := Sys (
            Item    => C.To_C ("ksh -c " & '"' & Command & " &" & '"'));
    end if ;
    --
    if (Return_Code /= 0) then
        Success := False ;
    else
        Success := True ;
    end if;
    --
end UTIL.Perform_System_Command ;

If you want to actually interface to some OS service that is normally got to
via a subprogram call, then perhaps if you post the call (I presume it is
written in C?) we could help you with the appropriate pragmas, linkage, etc.

A Solution Does Exist, but you might need to be a little more specific.

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com
Web:      http://www.mcondic.com/


"Matt Raikes" <mraikes@vt.edu> wrote in message
news:ab21b49a.0107101051.766f947a@posting.google.com...
> Is there a way to call a Unix executable(such as gzip) from within my
code.

Re: Unix Executables

[M. A. Alves]

On 10 Jul 2001, Matt Raikes wrote:
> Is there a way to call a Unix executable(such as gzip) from within my code.

Many ways.  Function Posix.System, for example.

-----

package Posix is

  function System(Command: String) return Integer;

end Posix;

-----

with Interfaces.C; use Interfaces.C;
with Interfaces.C.Strings; use Interfaces.C.Strings;

package body Posix is

  function C_System(Command: chars_ptr) return int;
  pragma Import(C, C_System, "system");

  function System(Command: String) return Integer is
    C_Command : aliased char_array := To_C(Command);
  begin

return(Integer(C_System(To_Chars_Ptr(C_Command'Unrestricted_Access))));
  end System;

end Posix;

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