#include "main.h"

//======================================================================
/*
$ ps aux # a:all users, u:detailled, x:daemons // look at bash  PID

Socket = bidirectionnal ; choose an extremity
PARENT					   		CHILD
		[1]	>> SOCKFD >> [0]
			<< SOCKFD <<
*/
//======================================================================
int main(int argc, char **argv)
{
	int ok;
	int value=100;
	char *msg;
	char buffer[0x100];
	int sockFd[2];
	
	bool usePause=false;
	bool useSock=false;
	
	// Parse Args
	for(int i=1;i<argc;++i)
	  {
		  if(!strcmp(argv[i],"pause")) usePause=true;
	  }
	
	
	ok = socketpair(PF_LOCAL,SOCK_STREAM,0,sockFd);
						if( ok == -1 ) { perror("pipe"); exit(1); }
	
	pid_t child=fork(); //>>>>>>>> CREATE CHILD >>>>>>>>>>>>>>>>>>>>>>>>
  
	switch(child)
	{
		case -1: perror("fork"); return EXIT_FAILURE; break;
		
		//############ CHILD CODE ######################################
		case 0 : 
			  close(sockFd[1]); // child will not use this end
			  msg="first message from child to parent\n";
			  write(sockFd[0],msg,strlen(msg));  
			  if(usePause) { sleep(1); } 
			  msg="second message from child to parent\n";
			  write(sockFd[0],msg,strlen(msg));
			  shutdown(sockFd[0],SHUT_WR); // done with writing
			  for(;;)
					{
					int r=read(sockFd[0],buffer,0xFF);
							if(r==0) break; // end of file
							if(r==-1) { perror("read"); exit(1); }
					buffer[r]='\0';
					printf("child received [%s]\n",buffer);
					}
			  close(sockFd[0]); // done with reading

			break;		
		
		//############ PARENT CODE #####################################
		default : 
			  close(sockFd[0]); // parent will not use this end
			  for(;;)
					{
					int r=read(sockFd[1],buffer,0xFF);
									if(r==0) break; // end of file
									if(r==-1) { perror("read"); exit(1); }
					buffer[r]='\0';
					printf("parent received [%s]\n",buffer);
					}
			  const char *msg="first message from parent to child\n";
			  write(sockFd[1],msg,strlen(msg)); 
			  if(usePause) { sleep(1); } 
			  msg="second message from parent to child\n";
			  write(sockFd[1],msg,strlen(msg));
			  close(sockFd[1]); // done with writing

			int status;
		    pid_t p=waitpid(child,&status,0);	// PARENT MUST WAIT FOR HIS CHILD
								if(p==-1) { perror("waitpid");  return EXIT_FAILURE; }
			break;
	}	
			
return EXIT_SUCCESS;
}
//^^^^^^^^^^^^^^^^^^^^^^^^^^ EOF ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^