ExecUtils.h

#include <sys/wait.h>

enum PIPE_FILE_DESCRIPTERS
{
	  READ_FD  = 0,
		  WRITE_FD = 1
};

enum CONSTANTS
{
	  BUFFER_SIZE = 100
};

#define ASSERT_IS(a, b) assert(a == b)
#define ASSERT_NOT(a, b) assert( a != b)
#define FAIL(s) printf("%s\n", s); exit(-1);

void execute(string binaryPath){
  int       parentToChild[2];
  int       childToParent[2];
  pid_t     pid;
  string    dataReadFromChild;
  char      buffer[ BUFFER_SIZE + 1 ];
  ssize_t   readResult;
  int       status;

  ASSERT_IS(0, pipe(parentToChild));
  ASSERT_IS(0, pipe(childToParent));

  switch ( pid = fork() )
  {
    case -1:
      FAIL( "Fork failed" );
      exit(-1);

    case 0: /* Child */
      ASSERT_NOT(-1, dup2( parentToChild[ READ_FD  ], STDIN_FILENO  ) );
      ASSERT_NOT(-1, dup2( childToParent[ WRITE_FD ], STDOUT_FILENO ) );
      ASSERT_NOT(-1, dup2( childToParent[ WRITE_FD ], STDERR_FILENO ) );
      ASSERT_IS(  0, close( parentToChild [ WRITE_FD ] ) );
      ASSERT_IS(  0, close( childToParent [ READ_FD  ] ) );

          /*   file,  arg0,  arg1,   arg2 */
      execlp(  "python",  "python",  "rewrite-binary.py",  binaryPath.c_str() );

      FAIL( "This line should never be reached!!!" );
      exit(-1);


    default: /* Parent */
      cout << "Child " << pid << " process running..." << endl;

      ASSERT_IS(  0, close( parentToChild [ READ_FD  ] ) );
      ASSERT_IS(  0, close( childToParent [ WRITE_FD ] ) );

      while ( true )
      {
        switch ( readResult = read( childToParent[ READ_FD ],
                                    buffer, BUFFER_SIZE ) )
        {
          case 0: /* End-of-File, or non-blocking read. */
            cout << "End of file reached..."         << endl
                 << "Data received was ("
                 << dataReadFromChild.size() << "):" << endl
                 << dataReadFromChild                << endl;

            ASSERT_IS( pid, waitpid( pid, & status, 0 ) );

            cout << endl
                 << "Child exit staus is:  " << WEXITSTATUS(status) << endl
                 << endl;

            exit(0);


          case -1:
            if ( (errno == EINTR) || (errno == EAGAIN) )
            {
              errno = 0;
              break;
            }
            else
            {
              FAIL( "read() failed" );
              exit(-1);
            }

          default:
            dataReadFromChild . append( buffer, readResult );
            break;
        }
      } /* while ( true ) */
  } /* switch ( pid = fork() )*/
}