www.pudn.com > closeonexec.rar > usefd.cpp

// This program is written by Li,Suke. 
// School of Software and Microelectronics, 
// Beijing University. 
// I hope this program can be useful. 
// September 11, 2006 
 
#include  
#include  
#include  
using namespace std; 
 
int main(int argc, char *argv[]) 
{ 
  const char *msg = " This is from usedfd. "; 
  if (argc != 2) { 
     cout << "Usage usefd  " << endl; 
     exit(1); 
  } 
  int fd = atoi(argv[1]); 
 
  cout << "usefd:The file descriptor from usefd is " << fd << endl; 
   
  if (fd > 0) { 
     int n = write(fd, msg, strlen(msg)); 
 
     if (n < 0) { 
        perror("write"); 
        exit(1); 
     } 
  } 
  return 0;   
 
}