我需要在程序中启动两个外部程序,并将第一个程序的STDOUT连接到第二个程序的STDIN.如何在Delphi中实现这一目标(RAD Studio 2009,如果重要的话)？我在
Windows环境中运行.
作为命令行命令,我的情况看起来像这样：
dumpdata.exe | encrypt.exe "mydata.dat"
解决方法
一个似乎有效的快速测试(受到
JCL的重大启发)：
child1：说’你好,世界！’ 3倍至标准输出
program child1;
{$APPTYPE CONSOLE}
uses
SysUtils;
procedure Main;
var
I: Integer;
begin
for I := 0 to 2 do
Writeln('Hello,world!');
Write(^Z);
end;
begin
try
Main;
except
on E: Exception do
begin
ExitCode := 1;
Writeln(ErrOutput,Format('[%s] %s',[E.ClassName,E.Message]));
end;
end;
end.
child2：回显OutputDebugString的标准输入(可以通过DebugView查看)
program child2;
{$APPTYPE CONSOLE}
uses
Windows,SysUtils,Classes;
procedure Main;
var
S: string;
begin
while not Eof(Input) do
begin
Readln(S);
if S <> '' then
OutputDebugString(PChar(S));
end;
end;
begin
try
Main;
except
on E: Exception do
begin
ExitCode := 1;
Writeln(ErrOutput,E.Message]));
end;
end;
end.
parent：启动child1重定向到child2
program parent;
{$APPTYPE CONSOLE}
uses
Windows,Classes,SysUtils;
procedure ExecutePiped(const CommandLine1,CommandLine2: string);
var
StartupInfo1,StartupInfo2: TStartupInfo;
ProcessInfo1,ProcessInfo2: TProcessInformation;
SecurityAttr: TSecurityAttributes;
PipeRead,PipeWrite: THandle;
begin
PipeWrite := 0;
PipeRead := 0;
try
SecurityAttr.nLength := SizeOf(SecurityAttr);
SecurityAttr.lpSecurityDescriptor := nil;
SecurityAttr.bInheritHandle := True;
Win32Check(CreatePipe(PipeRead,PipeWrite,@SecurityAttr,0));
FillChar(StartupInfo1,SizeOf(TStartupInfo),0);
StartupInfo1.cb := SizeOf(TStartupInfo);
StartupInfo1.dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
StartupInfo1.wShowWindow := SW_HIDE;
StartupInfo1.hStdInput := GetStdHandle(STD_INPUT_HANDLE);
StartupInfo1.hStdOutput := PipeWrite;
StartupInfo1.hStdError := GetStdHandle(STD_ERROR_HANDLE);
FillChar(StartupInfo2,0);
StartupInfo2.cb := SizeOf(TStartupInfo);
StartupInfo2.dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
StartupInfo2.wShowWindow := SW_HIDE;
StartupInfo2.hStdInput := PipeRead;
StartupInfo2.hStdOutput := GetStdHandle(STD_OUTPUT_HANDLE);
StartupInfo2.hStdError := GetStdHandle(STD_ERROR_HANDLE);
FillChar(ProcessInfo1,SizeOf(TProcessInformation),0);
FillChar(ProcessInfo2,0);
Win32Check(CreateProcess(nil,PChar(CommandLine2),nil,True,NORMAL_PRIORITY_CLASS,StartupInfo2,ProcessInfo2));
Win32Check(CreateProcess(nil,PChar(CommandLine1),StartupInfo1,ProcessInfo1));
WaitForSingleObject(ProcessInfo2.hProcess,INFINITE);
finally
if PipeRead <> 0 then
CloseHandle(PipeRead);
if PipeWrite <> 0 then
CloseHandle(PipeWrite);
if ProcessInfo2.hThread <> 0 then
CloseHandle(ProcessInfo2.hThread);
if ProcessInfo2.hProcess <> 0 then
CloseHandle(ProcessInfo2.hProcess);
if ProcessInfo1.hThread <> 0 then
CloseHandle(ProcessInfo1.hThread);
if ProcessInfo1.hProcess <> 0 then
CloseHandle(ProcessInfo1.hProcess);
end;
end;
procedure Main;
begin
ExecutePiped('child1.exe','child2.exe');
end;
begin
try
Main;
except
on E: Exception do
begin
ExitCode := 1;
Writeln(Error,E.Message]));
end;
end;
end.