Question

我正在遵循此example，但代码太多了，我真的不确定他们在哪里使用了一些简化。因此，我尝试创建一个简短得多的示例，但无法使管道正常工作。

#include <cstdlib>
#include <cstdio>
#include <windows.h>

int main() {
  HANDLE g_hChildStd_IN_Rd = NULL;
  HANDLE g_hChildStd_IN_Wr = NULL;
  HANDLE g_hChildStd_OUT_Rd = NULL;
  HANDLE g_hChildStd_OUT_Wr = NULL;

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

  char* command = "example.exe";
  if (! CreatePipe(&g_hChildStd_IN_Rd, &g_hChildStd_IN_Wr, &saAttr, 0)) printf("Stdin CreatePipe"); 
  if (! CreatePipe(&g_hChildStd_OUT_Rd, &g_hChildStd_OUT_Wr, &saAttr, 0) ) printf("StdoutRd CreatePipe"); 

  STARTUPINFO siStartInfo = {};
  PROCESS_INFORMATION piProcInfo = {}; 
  siStartInfo.cb = sizeof(STARTUPINFO); 
  siStartInfo.hStdError = g_hChildStd_OUT_Wr;
  siStartInfo.hStdOutput = g_hChildStd_OUT_Wr;
  siStartInfo.hStdInput = g_hChildStd_IN_Rd;
  siStartInfo.dwFlags = STARTF_USESTDHANDLES;

  CreateProcess(NULL, 
      command,            // command line 
      NULL,               // process security attributes 
      NULL,               // primary thread security attributes 
      TRUE,               // handles are inherited 
      CREATE_NEW_CONSOLE, // creation flags 
      NULL,               // use parent's environment 
      NULL,               // use parent's current directory 
      &siStartInfo,       // STARTUPINFO pointer 
      &piProcInfo);       // receives PROCESS_INFORMATION 

  Sleep(1000);
  printf("writing to process\n");
  DWORD dwWritten; 
  WriteFile(siStartInfo.hStdInput, "hello world", 11, &dwWritten, NULL);

  printf("reading from process\n");
  DWORD dwRead; 
  const int BUFSIZE = 1024;
  CHAR chBuf[BUFSIZE]; 

  ReadFile(siStartInfo.hStdOutput, chBuf, BUFSIZE, &dwRead, NULL);
  if ( dwRead > 0 ) {
    printf("Read from the pipe: %s\n", chBuf);
  } else {
    printf("Nothing to read from stdout.\n");
  }

  return 0; 
}

example.exe似乎永远都不会接收任何数据，无论我将哪个管道手柄放入WriteFile-Line中。

example.exe只是一个伪程序，如下所示：

#include <cstdlib>
#include <cstdio>

int main() {
  printf("This is an external process.\n");
  char Buffer[1024];
  fgets(Buffer, 1024 , stdin);
  printf("GOT: %s\n", Buffer);
  return 0;
}

我想知道的是如何设置管道，以便在使用管道启动过程时可以对其进行读写操作。

视窗。创建一个流程并使用其管道

0 个答案: