捕获远程进程的子进程的标准输出

Question

Currently working on a situation where I need to capture the stdout/stderr for a child process of an external process. For this situation would I need a named pipe?

I have currently tried the following:

SECURITY_ATTRIBUTES saAttr;
HANDLE hStdOutRd = NULL;
HANDLE hStdOutWr = NULL;
HANDLE hDupStdOutWr = NULL;

saAttr.nLength = sizeof(SECURITY_ATTRIBUTES); 
saAttr.bInheritHandle = TRUE; 
saAttr.lpSecurityDescriptor = NULL; 

CreatePipe(&hStdOutRd, &hStdOutWr, &saAttr, 0) ) 
SetHandleInformation(hStdOutRd, HANDLE_FLAG_INHERIT, 0) )

HANDLE hExProc = OpenProcess(PROCESS_DUP_HANDLE, false, EXTERNAL_PROC);
DuplicateHandle(GetCurrentProcess(), 
                hStdOutWr, 
                hExProc,
                &hDupStdOutWr, 
                0,
                TRUE,
                DUPLICATE_SAME_ACCESS);

// Child process for EXTERNAL_PROC executes and should inherit the duplicated handle
// Read from hStdOutRd

When reading from the pipe, it either hangs or doesn't return anything. I'm assuming this is the case that it is an anonymous pipe and only works for parent-child processes and not external processes. I would prefer to not use a Named Pipe, would it be possible to DuplicateHandle() the pipes back from the remote process to my process and then access the data? If so, what would that look like?

Answer 1

No, you do not need to use a named pipe, an anonymous pipe will do fine. MSDN provides a full example of capturing output from a child process:

Creating a Child Process with Redirected Input and Output