GetCommandLine(),....SetCommandLine() ?

[Elias]

Hello.
Usually, You can only pass command lines to programs only when launching
then!
Don't know if there is an answer to my question, but i'll give it a try:
Can i set program's command line on runtime?

I want to be able to create a process using CreateProcess()
and at a certain point, I'll suspend it and set a new command line and then
resume it....Is that possible?

-elias
http://eassoft.cjb.net

[Rob Kennedy]

"Elias" <elias_ba...@yahoo.com> wrote in message
news:3aefbcf9_1@dnews...

I don't know, but I don't understand why you'd want to do that. Since
command lines don't generally change, why would a program ever process its
command line more than once? If your ultimate goal is just to change the
behavior of the program, there are several other well-established methods of
inter-process communication available. Describe what it is you're really
trying to accomplish by changing the command line.

--Rob

[Elias]

True, the application only processes it's command line only once,
but i want to createprocess in suspended mode w/o passing command line
params first and then SetCommandLine.
and then resume it.

-elias

"Rob Kennedy" <rike...@students.wisc.edu> wrote in message
news:3aefbf46$2_1@dnews...

[Leonid Troyanovsky]

Elias wrote:

> True, the application only processes it's command line only once,
> but i want to createprocess in suspended mode w/o passing command line
> params first and then SetCommandLine.
> and then resume it.

If you create a process in suspend mode, then a process is not initialize.
Use a pipe for standart input instead.

--
WBR, LVT.

[Elias]

Never used pipes....
Will they allow me to SetCommandLine() when the process is executed?

"Leonid Troyanovsky" <lv...@eco-pro.ru> wrote in message
news:3AEFCDD7...@eco-pro.ru...

[Leonid Troyanovsky]

Elias wrote:

> Never used pipes....
> Will they allow me to SetCommandLine() when the process is executed?

No, they only allow you to pass parameters into a child process.

--
WBR, LVT.

[Leonid Troyanovsky]

Elias wrote:

> Never used pipes....

This exapmle of redirection standart _output_ of child process to pipe:

program childRD;

uses
Windows,
SysUtils,
Dialogs,
uchildRD in 'uchildRD.pas';

var
s : String;

begin
s := InputBox('cmd','command','cmd /c echo Hi');
ShowMessage(ExecRD(s,2000));
end.

--
WBR, LVT.

-------------------------------uchildRD.pas-------------------------------

unit uchildRD;

interface

uses
Windows,
SysUtils;

function ExecRD (const cmdline : String; Timeout :Dword):String;

implementation

type
ThreadParams = record
hReadPipe : THandle;
s : String;
end;
PThreadParams = ^ThreadParams;

function ThreadRead(Params : Pointer):Dword; stdcall;
var
Info : PThreadParams;
Buffer : array [0..4095] of Char;
nb: DWord;
i: Longint;
begin
Result := 0;
Info := PThreadParams(Params);
while ReadFile( Info^.hReadPipe,
buffer,
SizeOf(buffer),
nb,
nil) do
begin
if nb = 0 then
Break;
for i:=0 to nb-1 do
if buffer[i] = #10 then
Info^.s := Info^.s + #13#10
else
if buffer[i] <> #13 then
Info^.s := Info^.s + buffer[i];
end;

end;

function OEMToStr(const OEM : String):String;
begin
SetLength(Result, Length(OEM));
OEMToChar(@OEM[1], @Result[1]);
end;

function ExecRD;
var
hReadPipe,
hWritePipe: THandle;
saPipe: TSecurityAttributes;

StartInfo: TStartupInfo;
ProcInfo: TProcessInformation;

Params : PThreadParams;
ReaderID : Dword;
ReaderHandle : THandle;

begin
Result := '';
Params := nil;
ReaderHandle := 0;

saPipe.bInheritHandle := true;
saPipe.lpSecurityDescriptor := nil;
saPipe.nLength := SizeOf(TSecurityAttributes);

if not CreatePipe(hReadPipe,hWritePipe,@saPipe,0) then
RaiseLastWin32Error;

FillChar(StartInfo,SizeOf(StartInfo),0);
StartInfo.dwFlags:= STARTF_USESTDHANDLES or
STARTF_USESHOWWINDOW;
StartInfo.wShowWindow:=SW_HIDE;
StartInfo.hStdOutput:= hWritePipe;
StartInfo.hStdError:= hWritePipe;
StartInfo.cb:=SizeOf(StartInfo);

try

if CreateProcess(nil,
PChar(cmdline),
nil,
nil,
True,
0,
nil,
nil,
StartInfo,
ProcInfo)
then
begin
CloseHandle(ProcInfo.hThread);
CloseHandle(hWritePipe);
end
else
RaiseLastWin32Error;

New(Params);
Params^.hReadPipe := hReadPipe;

ReaderHandle := CreateThread( nil,
0,
@ThreadRead,
Params,
0,
ReaderId);
if ReaderHandle = 0 then
RaiseLastWin32Error;

if WaitForSingleObject(ReaderHandle, Timeout) = WAIT_TIMEOUT then
begin
TerminateThread(ReaderHandle,0);
TerminateProcess(ProcInfo.hProcess, 1);
Result := 'Process terminated.'#13#10;
end;

Result := OEMToStr(Result+Params^.s);

finally
if ReaderHandle > 0 then
CloseHandle(ReaderHandle);
if ProcInfo.hProcess > 0 then
CloseHandle(ProcInfo.hProcess);
if hReadPipe > 0 then
CloseHandle(hReadPipe);
if Assigned(Params) then
Dispose(Params);
end;

end;
end.

[Rob Kennedy]

"Elias" <elias_ba...@yahoo.com> wrote in message

news:3aefc317_1@dnews...

> True, the application only processes it's command line only once,
> but i want to createprocess in suspended mode w/o passing command line
> params first and then SetCommandLine.
> and then resume it.

I still don't understand. Instead of creating the process and then setting
its command line (which I don't think you can do), why not figure out the
command line first and _then_ create the process?

Since you're creating the process suspended already, it will not have done
anything before you try setting its command line, so I don't see how that
would be any different from starting the process with the right command line
at the start.

--Rob