/*
 * Sample program for kill system call  - No.37
 *
 * kill - send signal to a process
 *
 * Synopsis
 *     #include <sys/types.h>
 *     #include <signal.h>
 *
 *     int kill(pid_t pid, int sig);
 *
 * Description
 *     The kill system call can be used to send any signal to any process
 *     group or process.
 *     
 *     If pid is positive, then sig is sent to pid.
 *
 *     If pid equals 0, then sig is sent to every process in the process group
 *     of the current process.
 *
 *     If pid equals -1, then sig is sent to every process except for process
 *     1 (init), but see below.
 *
 *     If pid is less than -1, then sig is sent to every process int the
 *     process group -pid.
 *
 *     If sig is 0, then no signal is sent, but error checking is still
 *     performed.
 *
 * Signals - <bits/signum.h>
 *     SIGHUP          1       * Hangup (POSIX).  *
 *     SIGINT          2       * Interrupt (ANSI).  *
 *     SIGQUIT         3       * Quit (POSIX).  *
 *     SIGILL          4       * Illegal instruction (ANSI).  *
 *     SIGTRAP         5       * Trace trap (POSIX).  *
 *     SIGABRT         6       * Abort (ANSI).  *
 *     SIGIOT          6       * IOT trap (4.2 BSD).  *
 *     SIGBUS          7       * BUS error (4.2 BSD).  *
 *     SIGFPE          8       * Floating-point exception (ANSI).  *
 *     SIGKILL         9       * Kill, unblockable (POSIX).  *
 *     SIGUSR1         10      * User-defined signal 1 (POSIX).  *
 *     SIGSEGV         11      * Segmentation violation (ANSI).  *
 *     SIGUSR2         12      * User-defined signal 2 (POSIX).  *
 *     SIGPIPE         13      * Broken pipe (POSIX).  *
 *     SIGALRM         14      * Alarm clock (POSIX).  *
 *     SIGTERM         15      * Termination (ANSI).  *
 *     SIGSTKFLT       16      * Stack fault.  *
 *     SIGCLD          SIGCHLD * Same as SIGCHLD (System V).  *
 *     SIGCHLD         17      * Child status has changed (POSIX).  *
 *     SIGCONT         18      * Continue (POSIX).  *
 *     SIGSTOP         19      * Stop, unblockable (POSIX).  *
 *     SIGTSTP         20      * Keyboard stop (POSIX).  *
 *     SIGTTIN         21      * Background read from tty (POSIX).  *
 *     SIGTTOU         22      * Background write to tty (POSIX).  *
 *     SIGURG          23      * Urgent condition on socket (4.2 BSD).  *
 *     SIGXCPU         24      * CPU limit exceeded (4.2 BSD).  *
 *     SIGXFSZ         25      * File size limit exceeded (4.2 BSD).  *
 *     SIGVTALRM       26      * Virtual alarm clock (4.2 BSD).  *
 *     SIGPROF         27      * Profiling alarm clock (4.2 BSD).  *
 *     SIGWINCH        28      * Window size change (4.3 BSD, Sun).  *
 *     SIGPOLL         SIGIO   * Pollable event occurred (System V).  *
 *     SIGIO           29      * IO now possible (4.2 BSD).  *
 *     SIGPWR          30      * Power failure restart (System V).  *
 *     SIGSYS          31      * Bad system call.  *
 *     SIGUNUSED       31
 *
 *     _NSIG           64      * Biggest signal number + 1
 *                                 (including real-time signals).  *
 */

#include <stdio.h>
#include <signal.h>

main()
{
	int pid;

	switch (pid = fork()) {
	case -1:
		exit(1);
		break;
	case 0:
		for(;;)
			printf("child\n");
		break;
	default:
		sleep(1);
		kill(pid, SIGKILL);
		printf("child process terminated\n");
		break;
	}

	exit(0);
}