How do I run a command-line program in Delphi?
Solution 1:
An example using ShellExecute()
:
procedure TForm1.Button1Click(Sender: TObject);
begin
ShellExecute(0, nil, 'cmd.exe', '/C find "320" in.txt > out.txt', nil, SW_HIDE);
Sleep(1000);
Memo1.Lines.LoadFromFile('out.txt');
end;
Note that using CreateProcess()
instead of ShellExecute()
allows for much better control of the process.
Ideally you would also call this in a secondary thread, and call WaitForSingleObject()
on the process handle to wait for the process to complete. The Sleep()
in the example is just a hack to wait some time for the program started by ShellExecute()
to finish - ShellExecute()
will not do that. If it did you couldn't for example simply open a notepad
instance for editing a file, ShellExecute()
would block your parent app until the editor was closed.
Solution 2:
Variant 1 (using the "advanced" CreateProcess):
This will run a 'DOS' program and retrieve its output:
function GetDosOutput(CommandLine: string; Work: string = 'C:\'): string; { Run a DOS program and retrieve its output dynamically while it is running. }
var
SecAtrrs: TSecurityAttributes;
StartupInfo: TStartupInfo;
ProcessInfo: TProcessInformation;
StdOutPipeRead, StdOutPipeWrite: THandle;
WasOK: Boolean;
pCommandLine: array[0..255] of AnsiChar;
BytesRead: Cardinal;
WorkDir: string;
Handle: Boolean;
begin
Result := '';
with SecAtrrs do begin
nLength := SizeOf(SecAtrrs);
bInheritHandle := True;
lpSecurityDescriptor := nil;
end;
CreatePipe(StdOutPipeRead, StdOutPipeWrite, @SecAtrrs, 0);
try
with StartupInfo do
begin
FillChar(StartupInfo, SizeOf(StartupInfo), 0);
cb := SizeOf(StartupInfo);
dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
wShowWindow := SW_HIDE;
hStdInput := GetStdHandle(STD_INPUT_HANDLE); // don't redirect stdin
hStdOutput := StdOutPipeWrite;
hStdError := StdOutPipeWrite;
end;
WorkDir := Work;
Handle := CreateProcess(nil, PChar('cmd.exe /C ' + CommandLine),
nil, nil, True, 0, nil,
PChar(WorkDir), StartupInfo, ProcessInfo);
CloseHandle(StdOutPipeWrite);
if Handle then
try
repeat
WasOK := windows.ReadFile(StdOutPipeRead, pCommandLine, 255, BytesRead, nil);
if BytesRead > 0 then
begin
pCommandLine[BytesRead] := #0;
Result := Result + pCommandLine;
end;
until not WasOK or (BytesRead = 0);
WaitForSingleObject(ProcessInfo.hProcess, INFINITE);
finally
CloseHandle(ProcessInfo.hThread);
CloseHandle(ProcessInfo.hProcess);
end;
finally
CloseHandle(StdOutPipeRead);
end;
end;
Variant 2:
Capture console output in [Realtime] and how it in a TMemo:
procedure CaptureConsoleOutput(const ACommand, AParameters: String; AMemo: TMemo);
const
CReadBuffer = 2400;
var
saSecurity: TSecurityAttributes;
hRead: THandle;
hWrite: THandle;
suiStartup: TStartupInfo;
piProcess: TProcessInformation;
pBuffer: array[0..CReadBuffer] of AnsiChar; <----- update
dRead: DWord;
dRunning: DWord;
begin
saSecurity.nLength := SizeOf(TSecurityAttributes);
saSecurity.bInheritHandle := True;
saSecurity.lpSecurityDescriptor := nil;
if CreatePipe(hRead, hWrite, @saSecurity, 0) then
begin
FillChar(suiStartup, SizeOf(TStartupInfo), #0);
suiStartup.cb := SizeOf(TStartupInfo);
suiStartup.hStdInput := hRead;
suiStartup.hStdOutput := hWrite;
suiStartup.hStdError := hWrite;
suiStartup.dwFlags := STARTF_USESTDHANDLES or STARTF_USESHOWWINDOW;
suiStartup.wShowWindow := SW_HIDE;
if CreateProcess(nil, PChar(ACommand + ' ' + AParameters), @saSecurity,
@saSecurity, True, NORMAL_PRIORITY_CLASS, nil, nil, suiStartup, piProcess)
then
begin
repeat
dRunning := WaitForSingleObject(piProcess.hProcess, 100);
Application.ProcessMessages();
repeat
dRead := 0;
ReadFile(hRead, pBuffer[0], CReadBuffer, dRead, nil);
pBuffer[dRead] := #0;
OemToAnsi(pBuffer, pBuffer);
AMemo.Lines.Add(String(pBuffer));
until (dRead < CReadBuffer);
until (dRunning <> WAIT_TIMEOUT);
CloseHandle(piProcess.hProcess);
CloseHandle(piProcess.hThread);
end;
CloseHandle(hRead);
CloseHandle(hWrite);
end;
end;
Source: delphi.wikia.com