#include <signal.h>

cat /usr/include/bits/signum.h
/* Signal number definitions.  Linux version.
   Copyright (C) 1995,1996,1997,1998,1999,2003 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifdef    _SIGNAL_H

/* Fake signal functions.  */
#define SIG_ERR    ((__sighandler_t) -1)        /* Error return.  */
#define SIG_DFL    ((__sighandler_t) 0)        /* Default action.  */
#define SIG_IGN    ((__sighandler_t) 1)        /* Ignore signal.  */

#ifdef __USE_UNIX98
# define SIG_HOLD    ((__sighandler_t) 2)    /* Add signal to hold mask.  */
#endif


/* Signals.  */
#define    SIGHUP        1    /* Hangup (POSIX).  */
#define    SIGINT        2    /* Interrupt (ANSI).  */
#define    SIGQUIT        3    /* Quit (POSIX).  */
#define    SIGILL        4    /* Illegal instruction (ANSI).  */
#define    SIGTRAP        5    /* Trace trap (POSIX).  */
#define    SIGABRT        6    /* Abort (ANSI).  */
#define    SIGIOT        6    /* IOT trap (4.2 BSD).  */
#define    SIGBUS        7    /* BUS error (4.2 BSD).  */
#define    SIGFPE        8    /* Floating-point exception (ANSI).  */
#define    SIGKILL        9    /* Kill, unblockable (POSIX).  */
#define    SIGUSR1        10    /* User-defined signal 1 (POSIX).  */
#define    SIGSEGV        11    /* Segmentation violation (ANSI).  */
#define    SIGUSR2        12    /* User-defined signal 2 (POSIX).  */
#define    SIGPIPE        13    /* Broken pipe (POSIX).  */
#define    SIGALRM        14    /* Alarm clock (POSIX).  */
#define    SIGTERM        15    /* Termination (ANSI).  */
#define    SIGSTKFLT    16    /* Stack fault.  */
#define    SIGCLD        SIGCHLD    /* Same as SIGCHLD (System V).  */
#define    SIGCHLD        17    /* Child status has changed (POSIX).  */
#define    SIGCONT        18    /* Continue (POSIX).  */
#define    SIGSTOP        19    /* Stop, unblockable (POSIX).  */
#define    SIGTSTP        20    /* Keyboard stop (POSIX).  */
#define    SIGTTIN        21    /* Background read from tty (POSIX).  */
#define    SIGTTOU        22    /* Background write to tty (POSIX).  */
#define    SIGURG        23    /* Urgent condition on socket (4.2 BSD).  */
#define    SIGXCPU        24    /* CPU limit exceeded (4.2 BSD).  */
#define    SIGXFSZ        25    /* File size limit exceeded (4.2 BSD).  */
#define    SIGVTALRM    26    /* Virtual alarm clock (4.2 BSD).  */
#define    SIGPROF        27    /* Profiling alarm clock (4.2 BSD).  */
#define    SIGWINCH    28    /* Window size change (4.3 BSD, Sun).  */
#define    SIGPOLL        SIGIO    /* Pollable event occurred (System V).  */
#define    SIGIO        29    /* I/O now possible (4.2 BSD).  */
#define    SIGPWR        30    /* Power failure restart (System V).  */
#define SIGSYS        31    /* Bad system call.  */
#define SIGUNUSED    31

#define    _NSIG        65    /* Biggest signal number + 1
                   (including real-time signals).  */

#define SIGRTMIN        (__libc_current_sigrtmin ())
#define SIGRTMAX        (__libc_current_sigrtmax ())

/* These are the hard limits of the kernel.  These values should not be
   used directly at user level.  */
#define __SIGRTMIN    32
#define __SIGRTMAX    (_NSIG - 1)

#endif    /* <signal.h> included.  */

       #include <sys/wait.h>
       #include <stdlib.h>
       #include <unistd.h>
       #include <stdio.h>

       int
       main(int argc, char *argv[])
       {
           pid_t cpid, w;
           int status;

           cpid = fork();
           if (cpid == -1) {
               perror("fork");
               exit(EXIT_FAILURE);
           }

           if (cpid == 0) {            /* Code executed by child */
               printf("Child PID is %ld\n", (long) getpid());
               if (argc == 1)
                   pause();                    /* Wait for signals */
               _exit(atoi(argv[1]));

           } else {                    /* Code executed by parent */
               do {
                   w = waitpid(cpid, &status, WUNTRACED | WCONTINUED);
                   if (w == -1) {
                       perror("waitpid");
                       exit(EXIT_FAILURE);
                   }

                   if (WIFEXITED(status)) {
                       printf("exited, status=%d\n", WEXITSTATUS(status));
                   } else if (WIFSIGNALED(status)) {
                       printf("killed by signal %d\n", WTERMSIG(status));
                   } else if (WIFSTOPPED(status)) {
                       printf("stopped by signal %d\n", WSTOPSIG(status));
                   } else if (WIFCONTINUED(status)) {
                       printf("continued\n");
                   }
               } while (!WIFEXITED(status) && !WIFSIGNALED(status));
               exit(EXIT_SUCCESS);
           }
       }

void sig_handler(int sig)
{
    printf("cathed signal %d\n",sig);
    exit(0);
}
int main(int argc,char **argv[])
{
    int i,errno,err;
    pid_t pid;
    // пока он спит, тестим его на восприимчивость сигналов
    for(i = 1;i < NSIG;i++)
    {
        if(i!=SIGSTOP&&i!= SIGKILL)
        {
            errno=0;
            err=signal(i, sig_handler);
            printf("sig %d, status %d, errno %d\n",i,err,errno);
        }
    }
    if((pid=fork())==0)
    {
        execl("./launch","./launch",0);
        sleep(30);
    }
}

void sig_handler(int sig)
{
    exit(0);
}
int main(int argc,char **argv[])
{
    int i,errno,err;
    pid_t pid;
    for(i = 1;i <NSIG;i++)
    {
        if(i!=SIGSTOP&&i!= SIGKILL)
        {
            err=kill(ЗДЕСЬ PID ПРОЦЕССА ДРУГОГО ПОЛЬЗОВАТЕЛЯ, i);
            printf("sig %d, status %d\n",i,err);
        }
    }
    if((pid=fork())==0)
    {
        execl("./launch","./launch",0);
        sleep(30);
    }
}