关于如何使用VC开发命令行获取命令返回值的问题？

[clwk]

搜了一段可以实现此功能：
ExecuteCmd(CString str)
{
SECURITY_ATTRIBUTES sa;
HANDLE hRead,hWrite;

sa.nLength = sizeof(SECURITY_ATTRIBUTES);
sa.lpSecurityDescriptor = NULL;
sa.bInheritHandle = TRUE;
if (!CreatePipe(&hRead,&hWrite,&sa,0))
{
MessageBox("Error on CreatePipe()!");
return NULL;
}
STARTUPINFO si={sizeof(si)};
PROCESS_INFORMATION pi;
si.hStdError = hWrite;
si.hStdOutput = hWrite;
si.wShowWindow = SW_HIDE;
si.dwFlags = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
TCHAR* cmdline=StringToChar(str);
if (!CreateProcess(NULL,cmdline,NULL,NULL,TRUE,NULL,NULL,NULL,&si,&pi))
{
MessageBox("Error on CreateProcess()!");
return NULL;
}
CloseHandle(hWrite);

char buffer[4096];
memset(buffer,0,4096);
CString output;
DWORD byteRead;
while(true)
{
if (ReadFile(hRead,buffer,4095,&byteRead,NULL) == NULL)
{
break;
}
output += buffer;
}
return output;
}

问题是：执行了一条python命令，由于返回值很多，Read的时候，不能逐条读取返回值，总是等到全部返回后，才能read操作结束，请问此问题该如何解决，请提供思路，多谢！

[schlafenhamster]

http://www.codeforge.com/read/41729/consolePipe.h__html

[赵4老师]

仅供参考：

#pragma comment(lib,"user32")
#include <stdio.h>
#include <string.h>
#include <windows.h>
int main() {
    SECURITY_ATTRIBUTES sa          = {0};
    STARTUPINFO         si          = {0};
    PROCESS_INFORMATION pi          = {0};
    HANDLE              hPipeOutputRead  = NULL;
    HANDLE              hPipeOutputWrite = NULL;
    HANDLE              hPipeInputRead   = NULL;
    HANDLE              hPipeInputWrite  = NULL;
    BOOL                bTest = 0;
    DWORD               dwNumberOfBytesRead = 0;
    DWORD               dwNumberOfBytesWrite = 0;
    CHAR                szMsg[100];
    CHAR                szBuffer[256];

    sa.nLength = sizeof(sa);
    sa.bInheritHandle = TRUE;
    sa.lpSecurityDescriptor = NULL;

    // Create pipe for standard output redirection.
    CreatePipe(&hPipeOutputRead,  // read handle
            &hPipeOutputWrite, // write handle
            &sa,      // security attributes
            0      // number of bytes reserved for pipe - 0 default
            );

    // Create pipe for standard input redirection.
    CreatePipe(&hPipeInputRead,  // read handle
            &hPipeInputWrite, // write handle
            &sa,      // security attributes
            0      // number of bytes reserved for pipe - 0 default
            );

    // Make child process use hPipeOutputWrite as standard out,
    // and make sure it does not show on screen.
    si.cb = sizeof(si);
    si.dwFlags     = STARTF_USESHOWWINDOW | STARTF_USESTDHANDLES;
    si.wShowWindow = SW_HIDE;
    si.hStdInput   = hPipeInputRead;
    si.hStdOutput  = hPipeOutputWrite;
    si.hStdError   = hPipeOutputWrite;

    CreateProcess (
          NULL, "cmd.exe",
          NULL, NULL,
          TRUE, 0,
          NULL, NULL,
          &si, &pi);

    // Now that handles have been inherited, close it to be safe.
    // You don't want to read or write to them accidentally.
    CloseHandle(hPipeOutputWrite);
    CloseHandle(hPipeInputRead);

    // Now test to capture DOS application output by reading
    // hPipeOutputRead.  Could also write to DOS application
    // standard input by writing to hPipeInputWrite.
    sprintf(szMsg, "ver\n");
    WriteFile(
          hPipeInputWrite,      // handle of the write end of our pipe
          &szMsg,               // address of buffer that send data
          strlen(szMsg),        // number of bytes to write
          &dwNumberOfBytesWrite,// address of number of bytes read
          NULL                  // non-overlapped.
          );

    while(TRUE)
    {
       bTest=ReadFile(
          hPipeOutputRead,      // handle of the read end of our pipe
          &szBuffer,            // address of buffer that receives data
          256,                  // number of bytes to read
          &dwNumberOfBytesRead, // address of number of bytes read
          NULL                  // non-overlapped.
          );

      if (!bTest){
          sprintf(szMsg, "Error #%d reading pipe.",GetLastError());
          printf("%s",szMsg);
          break;
      }

      // do something with data.
      szBuffer[dwNumberOfBytesRead] = 0;  // null terminate
      printf("%s",szBuffer);
      if ('>'==szBuffer[dwNumberOfBytesRead-1]) break;
    }

    sprintf(szMsg, "chcp\nexit\n");
    WriteFile(
          hPipeInputWrite,      // handle of the write end of our pipe
          &szMsg,               // address of buffer that send data
          strlen(szMsg),        // number of bytes to write
          &dwNumberOfBytesWrite,// address of number of bytes read
          NULL                  // non-overlapped.
          );

    while(TRUE)
    {
       bTest=ReadFile(
          hPipeOutputRead,      // handle of the read end of our pipe
          &szBuffer,            // address of buffer that receives data
          256,                  // number of bytes to read
          &dwNumberOfBytesRead, // address of number of bytes read
          NULL                  // non-overlapped.
          );

      if (!bTest){
          sprintf(szMsg, "Error #%d reading pipe.",GetLastError());
          printf("%s",szMsg);
          break;
      }

      // do something with data.
      szBuffer[dwNumberOfBytesRead] = 0;  // null terminate
      printf("%s",szBuffer);
    }

    // Wait for CONSPAWN to finish.
    WaitForSingleObject (pi.hProcess, INFINITE);

    // Close all remaining handles
    CloseHandle (pi.hProcess);
    CloseHandle (hPipeOutputRead);
    CloseHandle (hPipeInputWrite);

    return 0;
}
//C:\test>test
//Microsoft Windows [版本 5.2.3790]
//(C) 版权所有 1985-2003 Microsoft Corp.
//
//C:\test>ver
//
//Microsoft Windows [版本 5.2.3790]
//
//C:\test>chcp
//活动的代码页: 936
//
//C:\test>exit
//Error #109 reading pipe.
//C:\test>

[zgl7903]

试试上面用 CreateNamedPipe 创建命名管道， 然后 PeekNamedPipe 获取数据或其信息

[clwk]

PeekNamedPipe 这个试过了，不管用。 还是多谢你了。