Socket error
lazarus / 38-Networking and Web Programming

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xmldom · 2012-01-21 13:54

Hello. I need to use socket in my application.
I found this code on
http://www.linuxsoft.cz/article.php?id_article=125 :

Code: [Select]program IP_server; { -*- mode:delphi; -*- }
uses sockets,inet,linux;

const
   port = 4456;      { Cislo portu na kterem budeme naslouchat }

var
   s        : longint;       { socket }
   sin,sout : text;          { pascalske proudy }
   i        : integer;
   c        : char;
   pid      : longint;
   line     : string;
   addr     : TInetSockAddr;

function getName(addr :longint ):string;
var
   h  : THost;
   a  : longint;
begin
   a:=NetToHost(addr);
   h.AddressLookup(THostAddr(a));
   getName:=h.Name;
   h.done;
end;

begin
   s:=socket(AF_INET,SOCK_STREAM,0);
   if s=-1 then begin
      halt(1);
   end;
   addr.family:=AF_INET;  { Jedna se o adresu domeny INET, tj. IPv4 }
   addr.port:=ShortHostToNet(port);
   addr.addr:=0;          { Naslouchame na 0.0.0.0 tj. na vsech
rozhranich }
   if not bind(s,addr,sizeof(addr)) then halt(1);
   if not listen(s,5) then halt(1);
   while accept(s,addr,sin,sout) do begin
      pid:=fork;
      if pid=-1 then halt(2);
      if pid=0 then begin
         reset(sin);
         rewrite(sout);
         writeln('Server: prichozi spojeni od:',getName(addr.addr));
         writeln(sout,'Mnauu');
         repeat
            readln(sin,line);
            for i:=0 to length(line) div 2-1 do begin
               c:=line[i+1];
               line[i+1]:=line[length(line)-i];
               line[length(line)-i]:=c;
            end;
            writeln(sout,line);
         until eof(sin);
         close(sin);
         close(sout);
         halt(0);
      end;
   end;
end.Code: [Select]program Unix_Client;

uses sockets,inet;

const
   port = 4456;               { port serveru }

var
   s        : longint;        { socket }
   sin,sout : text;           { pascalske proudy }
   line     : string;
   addr     : TInetSockAddr;      { struktura pro connect }
   host     : THost;          { objekt hostitele (coz zni hrozne ucene
^_~) }

begin
   if paramcount<>1 then begin
      writeln('Usage: ',paramstr(0),' <address>');
      halt(4)
   end;
   s:=socket(AF_INET,SOCK_STREAM,0);
   if s=-1 then begin
      halt(1);
   end;
   host.NameLookup(paramstr(1));
   addr.family:=AF_INET;               { Rodina adres, tj AF_INET }
   addr.port:=ShortHostToNet(port);  
   addr.addr:=HostToNet(LongInt(host.IPAddress)); { IP adresa serveru
}
   host.done;
   if not connect(s,addr,sin,sout) then halt(2);
   reset(sin);
   rewrite(sout);
   repeat
      readln(sin,line);
      writeln(line);
      readln(line);
      if (line='') then break;
      writeln(sout,line)
   until false;
   close(sin);
   close(sout);
end.
  
But I can't compile it:
Code: [Select]f:\pascal>fpc ip-client.pas
Free Pascal Compiler version 2.4.2 [2011/03/08] for i386
Copyright (c) 1993-2010 by Florian Klaempfl
Target OS: Win32 for i386
Compiling ip-client.pas
Fatal: Can't find unit inet used by Unix_Client
Fatal: Compilation aborted
Error: c:\lazarus\fpc\2.4.2\bin\i386-win32\ppc386.exe returned an
error exitcode
 (normal if you did not specify a source file to be compiled)

f:\pascal>
f:\pascal>fpc ip-server.pas
Free Pascal Compiler version 2.4.2 [2011/03/08] for i386
Copyright (c) 1993-2010 by Florian Klaempfl
Target OS: Win32 for i386
Compiling ip-server.pas
Fatal: Can't find unit inet used by IP_server
Fatal: Compilation aborted
Error: c:\lazarus\fpc\2.4.2\bin\i386-win32\ppc386.exe returned an
error exitcode
 (normal if you did not specify a source file to be compiled)

f:\pascal>
Where I do an error?
Unit "inet" is not build in fpc?

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marcov · 2012-01-21 14:16

That's a very old example for FPC 1.0.

Better
- try one of the socketsuites (Synapse, Indy)
- or search for a newer (post 2005) example.

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Shebuka · 2012-01-23 11:00

I'v done recently a test project for a bug that is essentially what
you need to take inspiration from:
http://bugs.freepascal.org/view.php?id=20484 (attached file)