/*
	sharedmem.c

	Started by Jeff Ondich on 4/11/96
	Last modified on 4/3/02

	This program demonstrates how to use shared memory
	in Linux.
*/

#include	<sys/types.h>
#include	<sys/wait.h>
#include	<unistd.h>
#include	<string.h>
#include	<stdio.h>


char	pSharedBuffer[100];


int main( void )
{
	int			pid, status;


	/* Initialize the (un)shared memory. */

	strcpy( pSharedBuffer, "Mom, there's a singing moose outside!" );
	fprintf( stderr, "%s\n", pSharedBuffer );


	/* Fork a child process */

	pid = fork();
	if( pid == -1 )
	{
		perror( "fork() failure" );
	}

	else if( pid != 0 )
	{
		fprintf( stderr, "The parent %d is waiting.\n", getpid() );
		wait( &status );
		fprintf( stderr, "The state of affairs is: %s\n", pSharedBuffer );
	}

	else
	{
		fprintf( stderr, "The child %d will try to scare the moose.\n", getpid() );
		strcpy( pSharedBuffer, "The moose is gone now." );
	}

	fprintf( stderr, "%d is quitting\n", getpid() );

	return( 0 );
}