1 ------------------------------------------------------------------------------
3 -- GNAT LIBRARY COMPONENTS --
5 -- G N A T . E X P E C T . N O N _ B L O C K I N G _ S P A W N --
10 -- Copyright (C) 2002 Ada Core Technologies, Inc. --
12 -- GNAT is free software; you can redistribute it and/or modify it under --
13 -- terms of the GNU General Public License as published by the Free Soft- --
14 -- ware Foundation; either version 2, or (at your option) any later ver- --
15 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
16 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
17 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
18 -- for more details. You should have received a copy of the GNU General --
19 -- Public License distributed with GNAT; see file COPYING. If not, write --
20 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
21 -- MA 02111-1307, USA. --
23 -- As a special exception, if other files instantiate generics from this --
24 -- unit, or you link this unit with other files to produce an executable, --
25 -- this unit does not by itself cause the resulting executable to be --
26 -- covered by the GNU General Public License. This exception does not --
27 -- however invalidate any other reasons why the executable file might be --
28 -- covered by the GNU Public License. --
30 -- GNAT is maintained by Ada Core Technologies Inc (http://www.gnat.com). --
32 ------------------------------------------------------------------------------
34 -- This is the default version. Used everywhere except VMS.
36 separate (GNAT.Expect)
37 procedure Non_Blocking_Spawn
38 (Descriptor : out Process_Descriptor'Class;
40 Args : GNAT.OS_Lib.Argument_List;
41 Buffer_Size : Natural := 4096;
42 Err_To_Out : Boolean := False)
44 function Fork return Process_Id;
45 pragma Import (C, Fork, "__gnat_expect_fork");
46 -- Starts a new process if possible.
47 -- See the Unix command fork for more information. On systems that
48 -- don't support this capability (Windows...), this command does
49 -- nothing, and Fork will return Null_Pid.
51 Pipe1, Pipe2, Pipe3 : aliased Pipe_Type;
54 Arg_List : aliased array (1 .. Args'Length + 2) of System.Address;
56 Command_With_Path : String_Access;
59 -- Create the rest of the pipes
62 (Descriptor, Err_To_Out, Pipe1'Access, Pipe2'Access, Pipe3'Access);
66 Descriptor.Pid := Fork;
68 -- Are we now in the child (or, for Windows, still in the common
71 if Descriptor.Pid = Null_Pid then
73 Command_With_Path := Locate_Exec_On_Path (Command);
75 -- Prepare an array of arguments to pass to C
76 Arg := new String (1 .. Command_With_Path'Length + 1);
77 Arg (1 .. Command_With_Path'Length) := Command_With_Path.all;
78 Arg (Arg'Last) := ASCII.Nul;
79 Arg_List (1) := Arg.all'Address;
81 for J in Args'Range loop
82 Arg := new String (1 .. Args (J)'Length + 1);
83 Arg (1 .. Args (J)'Length) := Args (J).all;
84 Arg (Arg'Last) := ASCII.Nul;
85 Arg_List (J + 2 - Args'First) := Arg.all'Address;
88 Arg_List (Arg_List'Last) := System.Null_Address;
90 -- This does not return on Unix systems
92 Set_Up_Child_Communications
93 (Descriptor, Pipe1, Pipe2, Pipe3, Command_With_Path.all,
96 Free (Command_With_Path);
99 -- Did we have an error when spawning the child ?
101 if Descriptor.Pid < Null_Pid then
104 -- We are now in the parent process
106 Set_Up_Parent_Communications (Descriptor, Pipe1, Pipe2, Pipe3);
111 Descriptor.Buffer_Size := Buffer_Size;
113 if Buffer_Size /= 0 then
114 Descriptor.Buffer := new String (1 .. Positive (Buffer_Size));
116 end Non_Blocking_Spawn;