UDP Library/Component Suggestions
lazarus / 38-Networking and Web Programming

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lgrfbs · 2021-09-21 04:51

Hello
Now I've found some inspiration again to program a little.
I need a UDP library/component that works for both Linux and Windows,
what should I look for?

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sstvmaster · 2021-09-21 08:40

Here is an overview of network libraries:
https://wiki.lazarus.freepascal.org/Networking_libraries

You can use: LNet, Indy or Synapse.

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franciscoluiz · 2021-09-21 14:51

pls try upd super components
https://sourceforge.net/projects/udpsupercomponents/

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Warfley · 2021-09-23 01:00

I wouldn't use a library for UDP. UDP is a very simple protocol (as
you can only recieve full datagrams every transmission is only a
single read or write).

With the sockets unit this is very easy:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses
sockets; var  Sock: TSocket;  Addr: PSockAddr_in;  AddrLen: PSizeInt; 
AString: String;  DataSize: SizeInt;begin  Sock := fpsocket(AF_INET,
SOCK_DGRAM, 0);  if Sock < 0 then    WriteLn('Something  went horribly
wrong');  New(Addr);  New(AddrLen);  try    // Send a string stored in
AString to HOST_IP at PORT:    // Set address of receiver   
Addr^.sin_family := AF_INET;    Addr^.sin_port := HToNS(PORT);   
Addr^.sin_addr.s_addr := LongWord(StrToNetAddr(HOST_IP));    //
perform sending operation    fpSendTo(Sock,  Pointer(AString),
AString.Length, 0, Addr, SizeOf(Addr^);    // Receive Data and write
to AString:    SetLength(AString, 512); // 512 is the maximum datagram
size in many implementations    DataSize := fpRecvFrom(Sock, AString,
AString.Length, 0, Addr, AddrLen);    SetLength(AString, DataSize);  
WriteLn('Data received from ', NetAddrToStr(Addr^.sin_addr.s_addr), ':
' . AString);  finally    Dispose(Addr);    Dispose(AddrLen); 
end;end;
Or to simplify:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses
sockets; procedure SendString(Sock: TSocket; const AHost: String;
APort: Word, const Data: String);var  Addr: TSockAddr_IN;begin 
Addr^.sin_family := AF_INET;  Addr^.sin_port := HToNS(APort); 
Addr^.sin_addr.s_addr := LongWord(StrToNetAddr(AHost)); 
fpSendTo(Sock, Pointer(Data), Data.Length, 0, @Addr,
SizeOf(Addr));end; procedure ReceiveString(Sock: TSocket; out
SenderHost: String; out SenderPort: Word): String;var  addr:
PSockAddr_IN;  addrLen: PSizeInt;  DataSize: SizeInt;begin 
New(addr);  New(addrLen);  try    SetLength(Result, 512);    DataSize
:= fpRecvFrom(Sock, Pointer(Result), Result.Length, 0, addr,
addrLen);    SetLength(Result, DataSize);    SenderHost :=
NetAddrToStr(addr^.sin_addr.s_addr);    SenderPort :=
NToHs(addr.sin_port);  finally    Dispose(addr);    Dispose(addrLen); 
end;end; var  Sock: TSocket;  data: String;  HostIP: String =
'127.0.0.1';  HostPort: Word = 1337;begin  Sock := fpSocket(AF_INET,
SOCK_DGRAM, 0);  if Sock < 0 then    Exit; // error;  // Send console
input to host  ReadLn(data);  SendString(Sock, HostIP, Port, data); 
// Receive data:  data := ReceiveString(Sock, HostIP, Port); 
WriteLn('Received from ', HostIP, ':', Port, ' ', data);end;
This is pretty much all you need to work with UDP. I don't see any
reason to include some third party librar for using something that can
be expressed with two functions having each less than 10 lines of code