лабораторки по ОС препод Челноков / 2семестр / wi2 / chernok / lab32 / 32

/***************************************************************************
                          main.c  -  description
                             -------------------
    begin                : чФТ нБК  4 23:32:08 MSD 2004
    copyright            : (C) 2004 by бМЕЛУЕК
    email                : achernok@mail.ru
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <stdio.h>
#include <sys/types.h>
#include <signal.h>


static pid_t fpid,spid;
static int fd[2];
static void onsigint(int sig);
static void onsigusr11(int sig);
static void onsigusr12(int sig);
char buff[2];
int main(int argc, char *argv[])
{
  signal(SIGINT,&onsigint);
  fpid=getpid();
  pipe(fd);
  switch(spid=fork())
  {
    case -1:;
    case  0:
       signal(SIGUSR1,&onsigusr12);
       while(1)
          pause();
    default:
       signal(SIGUSR1,&onsigusr11);      
       buff[0]='1';
       buff[1]='2';
       write(fd[1],buff,2);
       kill(spid,SIGUSR1);
       while(1)
         pause();
  }
}
void onsigint(int sig)
{
  signal(SIGINT,&onsigint);
  printf("Recieved signal to abort process %d\n",getpid());
  exit(0);
}
void onsigusr11(int sig)
{
  signal(SIGUSR1,&onsigusr11);
  read(fd[0],buff,2);
  printf("Recieved from SECOND process: %s\n",buff);
  buff[0]='1';
  buff[1]='2';
  sleep(1);
  write(fd[1],buff,2);
  kill(spid,SIGUSR1); 
}
void onsigusr12(int sig)
{
  signal(SIGUSR1,&onsigusr12);
  read(fd[0],buff,2);
  printf("Recieved from FIRST  process: %s\n",buff);
  buff[0]='2';
  buff[1]='1';
  sleep(1);
  write(fd[1],buff,2);
  kill(fpid,SIGUSR1);
}