Good day, dear experts. Once again, collecting brains on the floor, I appeal to your help. I'm testing the application, among other things, during the execution, information is read from the console, and some bjaka happens at that time. It is necessary to localize the problem, but I can’t not only localize it, I can’t even understand how these pipes (pipes) work, and I don’t find something in the internet of the TSeartAttributes, TStartupInfo, etc. class notation. Here is a piece of code typical of this topic, please comment on what is happening there or advise where this topic is clearly described.

function ipconfig(v_cmd:string):string; const BUFSIZE = 2000; var SecAttr: TSecurityAttributes; hReadPipe, hWritePipe: THandle; StartupInfo: TStartUpInfo; ProcessInfo: TProcessInformation; Buffer: Pchar; WaitReason,BytesRead: DWord; l_str:string; i:integer; begin with SecAttr do begin nlength:= SizeOf(TSecurityAttributes); binherithandle:= true; lpsecuritydescriptor:= nil; end; if Createpipe(hReadPipe, hWritePipe, @SecAttr, 0) then begin Buffer:= AllocMem(BUFSIZE + 1); FillChar(StartupInfo, Sizeof(StartupInfo), #0); StartupInfo.cb:= SizeOf(StartupInfo); StartupInfo.hStdOutput:= hWritePipe; StartupInfo.hStdInput:= hReadPipe; StartupInfo.dwFlags:= STARTF_USESTDHANDLES + STARTF_USESHOWWINDOW; StartupInfo.wShowWindow:= SW_HIDE; if CreateProcess(nil, PChar('ipconfig '), @SecAttr, @SecAttr, true, NORMAL_PRIORITY_CLASS, nil, nil, StartupInfo, ProcessInfo) then begin repeat WaitReason:= WaitForSingleObject( ProcessInfo.hProcess,100); //Application.ProcessMessages; //WriteLn( WaitReason); until(WaitReason <> WAIT_TIMEOUT); repeat BytesRead := 0; ReadFile(hReadPipe, Buffer[0], BUFSIZE, BytesRead, nil); Buffer[BytesRead]:= #0; OemToAnsi(Buffer,Buffer); //Копим l_str := l_str + String(buffer); until(BytesRead < BUFSIZE); end; result:=l_str; FreeMem(Buffer); CloseHandle(ProcessInfo.hProcess); CloseHandle(ProcessInfo.hThread); CloseHandle(hReadPipe); CloseHandle(hWritePipe); end; end;

    1 answer 1

    Used here are StartUpInfo, SecurityAttributes, etc. are standard structures and functions of the Windows32 API. Documentation on them can be found on the website MSDN ( prooflink ). Regarding this procedure: it runs the ipconfig program with settings for output to the so-called. pipes (pipes) - line 26. Due to this, after the program is completed, the procedure can read the entire output of ipconfig into the console - lines 33 -38, and returns the resulting line.

    • I would like to add that WaitForSingleObject can return the value of WAIT_FAILED. What was not considered here, but, it seems to me, would be worth it. - Dex