list5-2.cpp

这是c++编程方面的名著的例子代码

// Listing 5-2
// Demonstates the use of  execl
// one of the family of exec( ) functions
// used to spawn child processes
// accepts a sequence of four integers that will be
// passed to the program from list5-1

#include <iostream.h>
#include <strstream.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>

void main(int argc, char *argv[])
{

 
   if(argc == 5){
      char Argument[81];
      strcpy(Argument,"");
      strstream Buffer;
      Buffer << "list5-1" << " ";
      Buffer << (atol(argv[1]) * 2) << " ";
      Buffer << (atol(argv[2]) * 3) << " ";
      Buffer << (atol(argv[3])+ atol(argv[1])) << " ";
      Buffer << atol(argv[4]) << ends;  
      Buffer >> argv[0];
      Buffer >> argv[1];
      Buffer >> argv[2];
      Buffer >> argv[3];
      Buffer >> argv[4];     
      cout << "Child Process Executes " << Buffer.str() << endl;     
      execvp("list5-1",argv);
   }

}