_N_了吧唧的_ 发表于 2018-8-31 09:39:37

perl Socket实例

  Perl socket programming tutorial
  Socket programming in perl can be done using the low level socket functions or the IO::Socket module.The IO::Socket module provides an object-oriented interface to the socket functions.
  In this tutorial we are going to use the low level socket functions.
  实例1:连接百度端口80
  # cat 1.pl
  #!/usr/bin/perl -w
  use strict;
  # The socket function can be used to create a socket.In the following code example we shall create a tcp socket.
  use Socket;
  my $proto = getprotobyname('tcp'); # get the tcp protocol
  # Create a socket handle(descriptor)
  socket(SOCKET,AF_INET,SOCK_STREAM,$proto) or die "cant create socket:$!\n";
  # Connecting to a remote server
  my $remote = 'www.baidu.com';
  my $port = 80;
  my $iaddr= inet_aton($remote) or die "unable to resolve hostname: $remote\n";
  my $paddr = sockaddr_in($port,$iaddr); # socket address structure
  connect(SOCKET,$paddr) or die "connect failed : $!\n";
  print "Connected to $remote on port $port\n";
  # Close a socket
  close SOCKET,
  exit(0);
  In the above example we connected to baidu.com on port 80.
  Before the connect function is called the sockaddr_in structure has to be setup.
  The sockaddr_in structure stores the information about the remote address,
  address type and port number. The inet_aton function converts a hostname/ip to
  ip address in long number format.
  # cat 1.pl
  #!/usr/bin/perl -w
  use strict;
  # The socket function can be used to create a socket.In the following code example we shall create a tcp socket.
  use Socket;
  use Encode;
  my $proto = getprotobyname('tcp'); # get the tcp protocol
  # Create a socket handle(descriptor)
  socket(SOCKET,AF_INET,SOCK_STREAM,$proto) or die "cant create socket:$!\n";
  # Connecting to a remote server
  my $remote = 'www.baidu.com';
  my $port = 80;
  my $iaddr= inet_aton($remote) or die "unable to resolve hostname: $remote\n";
  my $paddr = sockaddr_in($port,$iaddr); # socket address structure
  connect(SOCKET,$paddr) or die "connect failed : $!\n";
  print "Connected to $remote on port $port\n";
  # Send data
  # Once connected it's time to start communication by sending some data.The send function can be used for this.
  # Send some data to remote server - the HTTP GET command
  send(SOCKET,"GET / HTTP/1.0\n\n",0) or die "send failed:$!\n";
  # Receive reply from server - perl way of reading from stream.
  # Can also do recv(SOCKET,$msg,2000,0).
  while(my $line = ) {
  #       $line = encode_utf8($line);
  $line = encode("utf-8",decode("gbk",$line));#(translate gbk code to utf-8 code)
  print "$line\n";
  }
  # Close a socket
  close SOCKET,
  exit(0);
  Revise
  In the above examples we learned the following socket operations.
  1. Create a socket
  2. Connect to remote server/system.
  3. Send data
  4. Receive a reply
  The socket program we wrote above is called a client.
  A client connects to a remote server for exchange of information/data.
  Apart from the client the other type of socket program we are going to write is called a server.
  The server serves data to clients connecting to it.
  So lets move on to the next section to do some server programming in perl.
  Server
  The basic steps for making a server are :
  1. Create a socket
  2. Bind to a local address and local port
  3. Listen for incoming connections
  4. Accept incoming connections
  5. Communicate the with the newly connected client - send and receive data.
  So a server does not connect out to a system, instead it waits for incoming connections.
  We have already seen how to create a socket.
  So the next task to make a server would be to bind the socket.
  The bind function can be used for this task.
  Lets take a quick example
  # cat server.pl
  #!/usr/bin/perl -w
  use strict;
  use Socket;
  $| = 1;
  #create a socket handle(descriptor)
  socket(SERVER,AF_INET,SOCK_STREAM,(getprotobyname('tcp'))) or die "cant create socket :$!\n";
  #bind to local port 10000
  my $port = 10000;
  #the socket is bound to port 10000 and address "any".After bind the socket has to be put in listen mode.
  bind(SERVER,sockaddr_in($port,INADDR_ANY)) or die "bind failed:$!\n";
  # listening the incoming connections
  listen(SERVER,10);
  print "Server is now listening...\n";
  # After calling listen,the socket is ready to accept incoming connections using the accept function.
  This shall be done in a loop so that the program can accept connections again and again.
  #accept incoming connections and talt to clients
  while(1) {
  my $addrinfo = accept(TALK,SERVER);
  my($port,$iaddr) = sockaddr_in($addrinfo);
  my $clienthost = gethostbyaddr($iaddr,AF_INET);
  print "Connection accepted from $clienthost:$port\n";
  # send some message to the client
  print TALK "hello client how are you\n";
  close TALK;
  }
  #close the socket
  close SERVER;
  exit(0);
  # telnet localhost 10000
  Trying 127.0.0.1...
  Connected to localhost.localdomain (127.0.0.1).
  Escape character is '^]'.
  hello client how are you
  Connection closed by foreign host.
  指定server的ip地址:
  # cat 2.pl
  #!/usr/bin/perl -w
  use strict;
  use Socket;
  $| = 1;
  #create a socket handle(descriptor)
  socket(SERVER,AF_INET,SOCK_STREAM,(getprotobyname('tcp'))) or die "cant create socket :$!\n";
  #bind to local port 10000
  my $port = 10000;
  my $server = "192.168.0.6";
  my $iaddr = inet_aton($server);
  my $paddr = sockaddr_in($port,$iaddr);
  #the socket is bound to port 10000 and address "any".After bind the socket has to be put in listen mode.
  bind(SERVER,$paddr) or die "bind failed:$!\n";
  # listening the incoming connections
  listen(SERVER,10);
  print "Server is now listening...\n";
  # After calling listen,the socket is ready to accept incoming connections using the accept function. This shall be done in a loop so that the program can accept connections again and again.
  #accept incoming connections and talt to clients
  while(1) {
  my $addrinfo = accept(TALK,SERVER);
  my($port,$iaddr) = sockaddr_in($addrinfo);
  my $clienthost = gethostbyaddr($iaddr,AF_INET);
  print "Connection accepted from $clienthost:$port\n";
  # send some message to the client
  print TALK "hello client how are you\n";
  close TALK;
  }
  #close the socket
  close SERVER;
  exit(0);
  高级技术:
  Asynchronouse I/O
  Multiple clients can be handled by asynchronous event driven I/O. IO::Select can be used for this.
  # cat iosocket.pl
  #!/usr/bin/perl -w
  use strict;
  use Socket;
  use IO::Select;
  $| = 1;
  my $socket;
  my $servtoclient;
  #create a socket handle(descriptor)
  my $proto = getprotobyname('tcp');
  socket($socket,PF_INET,SOCK_STREAM,$proto) or die "create socket failed:$!\n";
  #bind to local port
  my $port = 10001;
  my $server = "192.168.0.6";
  my $iaddr = inet_aton($server);
  my $paddr = sockaddr_in($port,$iaddr);
  bind($socket,$paddr) or die "bind failed:$!\n";
  #listen incoming connections
  listen($socket,10);
  print "Server $server on port $port is now listening ...\n";
  #accept incoming connections and talk to clients
  my $select = IO::Select->new();
  $select->add($socket);
  while(1) {
  my @ready = $select->can_read(0);
  foreach my $select_io(@ready) {
  #new connection read
  if($select_io == $socket) {
  my $clientinfo = accept($servtoclient,$socket);
  my($clientport,$clientiaddr) = sockaddr_in($clientinfo);
  my $clienthost = gethostbyaddr($clientiaddr,AF_INET);
  print "Connection accepted from $clienthost : $clientport\n";
  # send some message to the client
  send($servtoclient,"Hello client[$clienthost]! Nice to meet you !\n",0);
  $select->add($servtoclient);
  }
  # existing client read
  else {
  chop(my $clientinput = );
  chop($clientinput);
  if ($clientinput =~ /quit/i) {
  $select->remove($select_io);
  $select_io->close;
  }else {
  print "Received -- $clientinput\n";
  # send reply back to client
  send($select_io,"OK : $clientinput\n",0);
  }
  }
  }
  }
  #close the socket
  close $socket;
  exit(0);
  server端运行命令
  # perl iosocket.pl &
   3580
  # Server 192.168.0.6 on port 10001 is now listening ...
  #
  客户端访问:下面是服务器返回的信息
  # telnet 192.168.0.6 10001
  Trying 192.168.0.6...
  Connected to dou.perl.gov (192.168.0.6).
  Escape character is '^]'.
  Hello client! Nice to meet you !
  同时server端也返回信息:
  # Connection accepted from dou.perl.gov : 42617
  客户端开始发送信息:
  ls---->send
  OK : ls ---->receive
  hello---->send
  OK : hello ---->receive
  hello world---->send
  OK : hello world ---->receive
  同时server端也返回信息:
  Received -- ls
  Received -- hello
  Received -- hello world
  下面是更经典的iosocket程序:
  #!/usr/bin/perl -w
  use strict;
  use Socket;
  use IO::Select;
  $| = 1;
  my $path = "/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin";
  my @paths = split(/:/,$path);
  my $hit = 0;
  my $command;
  my @lines;
  my $line;
  my $socket;
  my $servtoclient;
  my $reply;
  #create a socket handle(descriptor)
  my $proto = getprotobyname('tcp');
  socket($socket,PF_INET,SOCK_STREAM,$proto) or die "create socket failed:$!\n";
  #bind to local port
  my $port = 10001;
  my $server = "192.168.0.6";
  my $iaddr = inet_aton($server);
  my $paddr = sockaddr_in($port,$iaddr);
  bind($socket,$paddr) or die "bind failed:$!\n";
  #listen incoming connections
  listen($socket,10);
  print "Server $server on port $port is now listening ...\n";
  #accept incoming connections and talk to clients
  my $select = IO::Select->new();
  $select->add($socket);
  while(1) {
  my @ready = $select->can_read(0);
  foreach my $select_io(@ready) {
  if($select_io == $socket) {
  my $clientinfo = accept($servtoclient,$socket);
  my($clientport,$clientiaddr) = sockaddr_in($clientinfo);
  my $clienthost = gethostbyaddr($clientiaddr,AF_INET);
  print "Connection accepted from $clienthost : $clientport\n";
  send($servtoclient,"Hello client[$clienthost]! Nice to meet you !\n",0);
  $select->add($servtoclient);}
  else {
  while(chop(my $clientinput = )) {
  chop($clientinput);
  $clientinput =~ s/^[ \t]*//;
  if ($clientinput =~ /quit/i) {
  $select->remove($select_io);
  $select_io->close;
  last;   # (跳出while循环jump out the loop of while)
  #close $socket;
  #exit 0;
  }else {
  @lines = split(/[ ]/,$clientinput);
  chomp($command = $lines);
  foreach my $dir (@paths) {
  search($dir);
  if ($hit == 1) {
  last; # (跳出foreach循环jump out the loop of foreach)
  }
  }
  if ($hit != 0) {
  send($select_io, "Command is [$command]:\n",0);
  $reply = `$clientinput`;
  #send reply back to client
  send($select_io,"$reply",0);
  } else {
  send($select_io,"you enter string [$clientinput]\n",0);
  }
  }
  }
  }
  }
  }
  #close the socket
  close $socket;
  exit(0);
  sub search {
  my $dir = shift;
  opendir(DIR,"$dir") or die "cant open dir:$dir:$!\n";
  my @files = readdir(DIR);
  closedir(DIR);
  foreach my $file (@files) {
  next if ($file =~ m/^\.$/ || $file =~ m/^\.\.$/);
  if ("$file" eq "$command") {
  $hit += 1;
  return(0);
  }else {
  $hit = 0;
  }
  }
  }
  服务器端:
  # perl 7.pl &
   3641
  # Server 192.168.0.6 on port 10001 is now listening ...
  # Connection accepted from dou.perl.gov : 33965
  客户端:
  # telnet 192.168.0.6 10001
  Trying 192.168.0.6...
  Connected to dou.perl.gov (192.168.0.6).
  Escape character is '^]'.
  Hello client! Nice to meet you !
  ls
  Command is :
  1.pl
  1.py
  2.pl
  44.pl
  4.pl
  5.pl
  6.pl
  7.pl
  aaa
  client.pl
  ht.pl
  iosocket.pl
  iosocket.pl.orig
  open_client.pl
  server.pl
  tk.pl
  hostname
  Command is :
  dou.perl.gov
  hostname
  Command is :
  dou.perl.gov
  quit
  Connection closed by foreign host.
  上述程序的说明:
  1)服务器端perl 7.pl &将程序至于后台运行
  2)客户端使用telnet进行测试
  3)可以输入linux中常用的命令:比如:ls hostname ifconfig eth0等。并且命令的前面可以有多个空格或者tap键。
  4)该程序通过搜索系统$PATH路径来确定输入的string是否是一个命令,如果是系统命令的话将$hit的值加1,程序
  通过控制$hit的值来觉得是否输出命令的结果,还是单纯的字符串。

页: [1]
查看完整版本: perl Socket实例