#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <netinet/in.h>
#include <netdb.h>

#define PORT 1023

const char MESSAGE[] = "Hi there!\n";

int main( void ) {
int                SrvSocket, ChildPid;
int                On = 1;
struct linger      Linger = { 0 };
char               Hostname[80];
struct hostent     *pHostEnt = NULL;
struct sockaddr_in ServerName = { 0 };

   SrvSocket = socket( PF_INET, SOCK_STREAM, IPPROTO_TCP );
   if( SrvSocket == -1 ) {
      perror( "Can't create socket!\n" );
      exit( 1 );
   }
   if( setsockopt( SrvSocket, SOL_SOCKET, SO_REUSEADDR, (const char*)&On, sizeof( On ) ) ) {
      perror( "Can't set reuse address on socket!\n" );
      exit( 1 );
   }
   Linger.l_onoff = 1;
   Linger.l_linger = 20;
   if( setsockopt( SrvSocket, SOL_SOCKET, SO_LINGER, (const char*)&Linger, sizeof( Linger ) ) ) {
      perror( "Can't set lingering for socket!\n" );
      exit( 1 );
   }
   if( gethostname( Hostname, sizeof( Hostname ) ) ) {
      perror( " Can't get my own hostname!\n" );
      exit( 1 );
   }
   pHostEnt = gethostbyname( Hostname );
   if( ! pHostEnt ) {
      perror( "Can't get hostentry!\n" );
      exit( 1 );
   }
   memset( &ServerName, 0, sizeof( ServerName ) );
   memcpy( &ServerName.sin_addr, pHostEnt->h_addr, pHostEnt->h_length );
   ServerName.sin_family = AF_INET;
   ServerName.sin_port = htons( PORT );
   if( bind( SrvSocket, (struct sockaddr*)&ServerName, sizeof( ServerName ) ) ) {
      perror( "Can't bind socket!\n" );
      exit( 1 );
   }
   if( listen(SrvSocket, BACKLOG ) ) {
      perror( "Can't listen on socket!\n" );
      exit( 1 );
   }
   while( 1 ) {
      struct sockaddr_in ClientName;
      int SlaveSocket, ClientLength = sizeof( ClientName );

      memset( &ClientName, 0, sizeof( ClientName ) );
      SlaveSocket = accept( SrvSocket, (struct sockaddr*)&ClientName, &ClientLength );
      if( SlaveSocket == -1 ) {
         perror( "Can't accept connection!\n" );
         exit( 1 );
      }
      ChildPid = fork();

sleep( 10 );

      switch( ChildPid ) {
         case -1:
            perror( "Can't fork!\n" );
            exit( 1 );
         case 0:
            close( SrvSocket );
            if( getpeername( SlaveSocket, (struct sockaddr*)&ClientName, &ClientLength )) {
               perror( "Can't get peername!\n" );
            } else {
               printf( "Connection request from %s\n", inet_ntoa( ClientName.sin_addr) );
            }
            write( SlaveSocket, MESSAGE, strlen( MESSAGE ) );
            close( SlaveSocket );
            exit( 0 );
         default:
            close( SlaveSocket );
      }
   }
   exit( 0 );
}