How to implement a server socket compatible to telnet?
in [ADA]
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From: snoopysalive on 20 Aug 2008 17:25 Come on guys, stop arguing. In the end, I've found a solution: ----------------------------------------------------------------------- with Ada.Text_IO, Ada.Exceptions, Ada.Streams, Ada.Unchecked_Deallocation, GNAT.Sockets; use Ada.Text_IO, Ada.Exceptions, Ada.Streams, GNAT.Sockets; procedure IP_Server is BUFFER_SIZE : constant Positive := 1024; type String_Access is access all String; procedure Free is new Ada.Unchecked_Deallocation (String, String_Access); CRLF : constant String := ASCII.CR & ASCII.LF; Host : constant String := "localhost"; Port : Port_Type := 7777; Address : Sock_Addr_Type; Server : Socket_Type; Client : Socket_Type; Channel : Stream_Access; Data : Stream_Element_Array (1..1); Offset : Stream_Element_Count; Buffer : String_Access := new String (1..BUFFER_SIZE); Cnt : Natural := 0; Test : Float := 0.0; begin -- IP_Server Initialize; Address.Addr := Addresses (Get_Host_By_Name (Host), 1); Address.Port := Port; Create_Socket (Server); Set_Socket_Option (Server, Socket_Level, (Reuse_Address, True)); Bind_Socket (Server, Address); Listen_Socket (Server); Accept_Socket (Server, Client, Address); Channel := Stream (Client); Cnt := 0; loop Read (Channel.all, Data (1..1), Offset); if Character'Val (Data (1)) = ASCII.CR or Character'Val (Data (1)) = ASCII.LF or Character'Val (Data (1)) = ASCII.NUL or Offset = 0 then exit; else Cnt := Cnt + 1; Buffer.all (Cnt) := Character'Val (Data (1)); end if; end loop; -- Read values from client-stream character by character. -- Reading should be stopped when Windows-linefeed or -- NULL was found, because telnet seams to be sending -- strings in a Windows-like format including the -- terminating \0-character known from C-strings. declare Old : String_Access := Buffer; begin Buffer := new String'(Buffer (1..Cnt)); Free (Old); end; -- The buffer-size of Str is 1024 elements. It's necessary -- to create a new String containing only relevant characters -- for being able to process the message further. declare Pong : String := "pong" & CRLF; O : Stream_Element_Array (1..Pong'length); begin if Buffer.all = "ping" then for I in Pong'range loop O (Stream_Element_Offset (I)) := Character'Pos (Pong (I)); end loop; Write (Channel.all, O); end if; end; -- If Buffer's message equals "ping" the server will -- send "pong" to the client. "pong" must be casted -- from String to Stream_Element_Array first. Close_Socket (Client); Close_Socket (Server); Finalize; exception when E : Socket_Error => Put_Line (Standard_Error, "Socket_Error => " & Exception_Message (E)); end IP_Server; ----------------------------------------------------------------------------------- Thanks to the thread under http://groups.google.com/group/comp.lang.ada/browse_thread/thread/c58b7bd180ea81b2 I found out how to read character by character from the client. However, it's not very comfortable to cast the echo-string manually but it's better than not being able to communicate with telnet or other C-based clients. Bye, Matthias
From: anon on 20 Aug 2008 18:57
But he wants to deal with Telnet. It states that in the title. And actually, a complete program PingPong is coded in the file "GNAT.Sockets.ads " which deals with both server and client code. Like I say KNOW your compiler and its packages That way you might be able to skip spending time seaching the internet or books. In <0baa592d-1291-4298-90e3-88ca85a476a8(a)k13g2000hse.googlegroups.com>, "snoopysalive(a)googlemail.com" <snoopysalive(a)googlemail.com> writes: >Come on guys, stop arguing. In the end, I've found a solution: > >----------------------------------------------------------------------- >with Ada.Text_IO, > Ada.Exceptions, > Ada.Streams, > Ada.Unchecked_Deallocation, > GNAT.Sockets; >use Ada.Text_IO, > Ada.Exceptions, > Ada.Streams, > GNAT.Sockets; > >procedure IP_Server is > > BUFFER_SIZE : constant Positive := 1024; > > type String_Access is access all String; > > procedure Free is new Ada.Unchecked_Deallocation > (String, String_Access); > > CRLF : constant String := ASCII.CR & ASCII.LF; > Host : constant String := "localhost"; > Port : Port_Type := 7777; > > Address : Sock_Addr_Type; > Server : Socket_Type; > Client : Socket_Type; > Channel : Stream_Access; > > Data : Stream_Element_Array (1..1); > Offset : Stream_Element_Count; > > Buffer : String_Access := new String (1..BUFFER_SIZE); > Cnt : Natural := 0; > > Test : Float := 0.0; > >begin -- IP_Server > Initialize; > > Address.Addr := Addresses (Get_Host_By_Name (Host), 1); > Address.Port := Port; > > Create_Socket (Server); > Set_Socket_Option (Server, Socket_Level, (Reuse_Address, True)); > Bind_Socket (Server, Address); > Listen_Socket (Server); > Accept_Socket (Server, Client, Address); > Channel := Stream (Client); > > Cnt := 0; > loop > Read (Channel.all, Data (1..1), Offset); > if Character'Val (Data (1)) = ASCII.CR or > Character'Val (Data (1)) = ASCII.LF or > Character'Val (Data (1)) = ASCII.NUL or > Offset = 0 then > exit; > else > Cnt := Cnt + 1; > Buffer.all (Cnt) := Character'Val (Data (1)); > end if; > end loop; > -- Read values from client-stream character by character. > -- Reading should be stopped when Windows-linefeed or > -- NULL was found, because telnet seams to be sending > -- strings in a Windows-like format including the > -- terminating \0-character known from C-strings. > > declare > Old : String_Access := Buffer; > begin > Buffer := new String'(Buffer (1..Cnt)); > Free (Old); > end; > -- The buffer-size of Str is 1024 elements. It's necessary > -- to create a new String containing only relevant characters > -- for being able to process the message further. > > declare > Pong : String := "pong" & CRLF; > O : Stream_Element_Array (1..Pong'length); > begin > if Buffer.all = "ping" then > for I in Pong'range loop > O (Stream_Element_Offset (I)) := Character'Pos (Pong (I)); > end loop; > Write (Channel.all, O); > end if; > end; > -- If Buffer's message equals "ping" the server will > -- send "pong" to the client. "pong" must be casted > -- from String to Stream_Element_Array first. > > Close_Socket (Client); > Close_Socket (Server); > > Finalize; > >exception when E : Socket_Error => > Put_Line (Standard_Error, "Socket_Error => " & Exception_Message >(E)); > >end IP_Server; >----------------------------------------------------------------------------------- > >Thanks to the thread under http://groups.google.com/group/comp.lang.ada/browse_thread/thread/c58b7bd180ea81b2 >I found out how to read character by character from the client. >However, it's not very comfortable to cast the echo-string manually >but it's better than not being able to communicate with telnet or >other C-based clients. > >Bye, >Matthias |