call external program from C++

call_external.cc

#include <iostream>
#include <string>
#include <windows.h>
#include <tchar.h>


void _tmain(int argc, TCHAR *argv[]) {
  STARTUPINFO si;
  PROCESS_INFORMATION pi;

  ZeroMemory(&si, sizeof(si));
  si.cb = sizeof(si);
  ZeroMemory(&pi, sizeof(pi));

  if (argc != 2) {
    printf("Usage: %s [cmdline]\n", argv[0]);
    return;
  }

  // Start the child process. 
  if (!CreateProcess(
    NULL,           // No module name (use command line)
    argv[1],        // Command line
    NULL,           // Process handle not inheritable
    NULL,           // Thread handle not inheritable
    FALSE,          // Set handle inheritance to FALSE
    0,              // No creation flags
    NULL,           // Use parent's environment block
    NULL,           // Use parent's starting directory 
    &si,            // Pointer to STARTUPINFO structure
    &pi)            // Pointer to PROCESS_INFORMATION structure
    ) {

    printf("CreateProcess failed (%d).\n", GetLastError());
    return;
  }

  // Wait until child process exits.
  WaitForSingleObject(pi.hProcess, INFINITE);

  // Close process and thread handles. 
  CloseHandle(pi.hProcess);
  CloseHandle(pi.hThread);

  printf("Running...");
}