Tutorial Addendum on Perl - Allotment B - Atrium Advice

In the telnet window, blazon in the afterward text:

    

 

    
Fish, I adulation you and account you actual much.

    
But I will annihilate you asleep afore this day ends.

    
.

    

The argument will be antipodal and alternate aback from the ReverseEchoer.pl:

    

 

    
Welcome to About-face Answer Server. 

    
.hcum yrev uoy tcepser dna uoy evol I ,hsiF

    
.sdne yad siht erofeb daed uoy llik lliw I tuB

    
.

    

Note that the telnet program is not announcement argument you typed in.

    

It alone displays the argument accustomed from ReverseEchoer.pl program.

    

SocketClient.pl - A Simple Atrium Applicant Application

    

Instead of using the telnet program, we can use the afterward program, SocketClient.pl,

    

to acquaint with ReverseEchoer.pl:

    

 

    
#- SocketClient.pl

    
#- Absorb (c) 1999 by Dr.  Yang

    
#

    
   $domain = 2; # Internet domain

    
   $type = 1; # Sequenced, reliable, two-way connection, byte streams

    
   $proto = 6; # Manual Ascendancy Agreement (TCP)

    
   socket(SOCK,$domain,$type,$proto);

    
   $host = pack( C4 , 127,0,0,1); # localhost = 127.0.0.1

    
   $port = 1024; 

    
   $address = pack( S n a4 x8 , $domain, $port, $host);

    
   bind(SOCK, $address);

    
   book STDOUT "Client host: ",join( . ,unpack( C4 , $host)),"

";

    
   book STDOUT "Client port: $port

";

    
   $sHost = pack( C4 , 127,0,0,1); # localhost = 127.0.0.1

    
   $sPort = 8888; 

    
   $sAddress = pack( S n a4 x8 , $domain, $sPort, $sHost);

    
   connect(SOCK, $sAddress);

    
   book STDOUT "Server host: ",join( . ,unpack( C4 , $sHost)),"

";

    
   book STDOUT "Server port: $sPort

";

    
   select(SOCK); $| = 1; select(STDOUT);

    
   while ($m=<SOCK>) {

    
      book STDOUT $m;

    
      $m = <STDIN>;

    
      book Beat $m;

    
   }

    
   close(SOCK);

    
   exit;

    

Note that:

    

    
• Setting $| to 1 is to about-face on auto even to the absence book handle. In adjustment to
  
      

  turn on auto even to SOCK, I accept to use select() action to about-face absence file
  
      

  handles.
  
      



    

Now, run ReverseEchoer.pl, then run SocketClient.pl in a separate command

    

window. If you blazon in the aforementioned argument as in the antecedent test, you will get

    

the afterward output:

    

 

    
Client host: 127.0.0.1

    
Client port: 1024

    
Server host: 127.0.0.1

    
Server port: 8888

    
Welcome to About-face Answer Server.

    
Fish, I adulation you and account you actual much.

    
.hcum yrev uoy tcepser dna uoy evol I ,hsiF

    
But I will annihilate you asleep afore this day ends.

    
.sdne yad siht erofeb daed uoy llik lliw I tuB

    
.

    

Network Account Functions

    

getprotobyname($protoName) - Allotment the agreement amount of the defined agreement name

    

in scalar context, and ($protoName,$aliases,$protoNumber) in account context.

    

getservbyname($serviceName,$protoName) - Allotment the anchorage amount of the specified

    

network account name and agreement name in scalar context, and

    

($serviceName,$aliases,$portNumber,$protoName) in account context.

    

getservbyport($portNumber,$protoName) - Allotment the arrangement account name of the specified

    

port amount and agreement name in scalar context, and

    

($serviceName,$aliases,$portNumber,$protoName) in account context.

    

gethostbyname($hostName) - Allotment the arranged IP abode of the specified

    

host name in scalar context, and ($name,$aliases,$addrtype,$length,@addrs) in list

    

context. The host name can aswell be defined in IP abode format.

    

gethostbyaddr($packedHostAddress) - Allotment the host name of the specified

    

packed IP abode in scalar context, and ($name,$aliases,$addrtype,$length,@addrs)

    

in account context.