Delphi calls external programs and blocks them into external programs

Background note:

Some time ago, a data conversion system was developed. The business logic stated that the data needed to be compressed into. tar.gz format.

I use Windows system, Mr. batch file processing, and then call WinExec to execute batch file, sleep and wait for a period of time, complete the automatic compression of data.

Later, it was found that the size of the file to be compressed is uncertain. Sleep fixed time when WinExec is executed alone may lead to compression failure, incomplete files or damage.

Optimizing scheme:

Instead of WinExe, CreateProcess is used to start processes, execute batch files, and the system automatically fills in the TProcess Information structure.

At this point, the program will automatically block into the batch, waiting for the end of the batch handle process or timeout. This can solve the problem of compression damage.

Give me an example Demo:

The D7 code is as follows:

 1 unit uMain;
 2 
 3 interface
 4 
 5 uses
 6   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 7   Dialogs, RzButton, StdCtrls;
 8 
 9 type
10   TFrmMain = class(TForm)
11     mmMsg: TMemo;
12     btnExecute: TRzBitBtn;
13     btnClear: TRzBitBtn;
14     procedure MsgDsp(v_Str: string);
15     procedure btnExecuteClick(Sender: TObject);
16     procedure btnClearClick(Sender: TObject);
17   private
18     { Private declarations }
19   public
20     { Public declarations }
21   end;
22 
23 var
24   FrmMain: TFrmMain;
25 
26 implementation
27 
28 {$R *.dfm}
29 
30 procedure TFrmMain.MsgDsp(v_Str: string);
31 begin
32   mmMsg.Lines.Add('[ admin ] - [' + v_Str + '] - [' + FormatDateTime('YYYY-MM-DD hh:mm:ss zzz', Now()) + ']');
33 end;
34 
35 procedure TFrmMain.btnExecuteClick(Sender: TObject);
36 var
37   sInfo: TStartupInfo;
38   pInfo: TProcessInformation;
39   cmdLine: string;
40   exitCode: Cardinal;
41 begin
42   MsgDsp('Initialization parameters');
43   cmdLine := 'C:\Program Files\7-Zip\7zFM.exe';
44   FillChar(sInfo, sizeof(sInfo), #0);
45   sInfo.cb := SizeOf(sInfo);
46   sInfo.dwFlags := STARTF_USESHOWWINDOW;
47   sInfo.wShowWindow := SW_NORMAL;
48   MsgDsp('Parameter initialization completed, start WinExec debugging');
49   //CreateProcess Used to start a process, After the process starts, Will fill in TProcessInformation This structure,
50   //At this point, the program blocks into the handle, waiting for the end of the process or timeout of the handle
51   if not CreateProcess(nil, pchar(cmdLine), nil, nil, false, CREATE_NEW_CONSOLE or NORMAL_PRIORITY_CLASS, nil, nil, sInfo, pInfo) then
52   begin
53     MsgDsp('WinExec Debugging failed!');
54     MessageBox(Application.handle, 'Designated program failed to start!', 'error', MB_OK or MB_ICONSTOP);
55   end
56   else
57   begin
58     //Waiting for process termination or timeout of the specified handle
59     WaitForSingleObject(pInfo.hProcess, INFINITE);
60     GetExitCodeProcess(pInfo.hProcess, exitCode);
61     MsgDsp('WinExec Successful debugging!');
62   end;
63 end;
64 
65 procedure TFrmMain.btnClearClick(Sender: TObject);
66 begin
67    mmMsg.Clear;
68 end;
69 
70 end.

The operation results are as follows: