Updating a two-way java messenger chat to allow multiplie users
java,multithreading,sockets,messenger,instant
Althoug a bit too broad for SO, I will give you a strategy for how to deal with this kind of server-client programs. For more information just hit your favorite search machine. There must be tons of articles. The basic strategy of a server handling multiple client requests is this:...
Java Socket returns EOF on low bandwidth
That happens when you have Client connected and then It disconnects and you are trying to read from it. I handle this asking the length of the message, If it is negative, I restart the connection. E.G. //CLIENTS LOOP while (true) { ... //MESSAGE LOOP while ( true ) {...
How to get the socket's specific error reason when POLLERR happens?
Call getsockopt() with the option SO_ERROR.
C# Winform to Connect to Device Using IP
As per request of the OP some information about using TcpClient and even TcpListener in case you need to create a server as well. Following link will help you get started with using TcpClient :https://msdn.microsoft.com/en-us/library/system.net.sockets.tcpclient%28v=vs.110%29.aspx?f=255&MSPPError=-2147217396 or this one in code project covers both client and server: http://www.codeproject.com/Articles/1415/Introduction-to-TCP-client-server-in-C in that code...
My get request for http is very slow [closed]
Try to modify String sender = "GET /docs/ HTTP/1.1\n" + "Host:localhost:8080\n"; with String sender = "GET /docs/ HTTP/1.0\n" + "Host:localhost:8080\n"; HTTP/1.1 is using keepalive by default, this may be related to your problem. Last resort you can try to send a Connection: close header...
Drawing with ncurses, sockets and fork
The problem is that your parent process is trying to do two different things that need waiting: "barber sleeps until someone wakes him" accept() Without some kind of joint waiting, this architecture does not work. Both pieces of code sleeps waiting for a single kind of event, disregarding the other...
Set a timeout for an UDP socket with Twisted (python)
I found a solution. When we use UDP, when we send a datagram, if no answer is received after less than 1 second, "self.transport" is set to None and "stopProtocol" method is called. Once we leave "stopProtocol" method, reactor stops to listen the specified UDP port. So this is my...
Get all room name in socket.io
This is not a proper response: [ 'pBtWJZqN23xAJw0sAAAE', 'test' ] [ 'GPnwtq3gi9t1RZcCAAAD', 'Lobby' ] [ 'n7tTlvoH1M7foT3ZAAAC', 'Lobby' ] Let me guess it is actually: [['pBtWJZqN23xAJw0sAAAE', 'test'], ['GPnwtq3gi9t1RZcCAAAD', 'Lobby'], ['n7tTlvoH1M7foT3ZAAAC', 'Lobby']] If it is not, then correct me. Just iterate through the array and collect values: var values = []; for...
Sending double with tcp from java to C#
In Java, DataOutputStream.writeDouble() converts the double to a long before sending, writing it High byte first (Big endian). However, C#, BinaryReader.ReadDouble() reads in Little Endian Format. In other words: The byte order is different, and changing one of them should fix your problem. The easiest way to change the byte...
Running a python script online for free (and accessing using ip and port) [closed]
python,sockets,web-hosting,host
I have temporarily hosted a FB app on pythonanywhere for free and it worked like a charm. In case you plan to use Django, the version they offer usually lags behind. In that case, I'd higly recommend using Openshift, by RedHat....
parameter error in python script & TOR proxy server
python,sockets,subprocess,tor,proxy-server
The issue is in DownloadYP.py - You do not have the files - C:\\rrr\japan\limit.txt I would suggest creating a dummy file in the above directory with that name, and try running the script again. Also, on a side note - You are mixing the os path separaters from unix and...
Detecting incoming port for TFTP data?
The TFTP protocol has the following flow: Client sends a RRQ or WRQ request from a randomly selected CTID port to port 69 on the server: Client:CTID ------> Server:69 Server replies from a randomly selected STID port to the client's CTID: Client:CTID <------ Server:STID all subsequent packets for that transfer...
Use Sockets in multiple *.cpp files
This question seems not specific to sockets, but to global variables in general. If you need to create a global variable (a socket, in this case) which must be accessible by multiple compilation units: You define the global variable in one single compilation unit (i.e. one cpp file) You declare...
Specified argument was out of the range of valid value to get data from network in c#
c#,sockets,buffer,streamwriter
Instead of this byte[] buffersend = new byte[client.ReceiveBufferSize]; buffersend = GetBytes("00010002000B0300010004C380"); int bytesSend = nwStream.Read(buffersend, 0, client.ReceiveBufferSize); nwStream.Write(buffersend, 0, bytesSend); I think you just want this. byte[] buffersend = GetBytes("00010002000B0300010004C380"); nwStream.Write(buffersend, 0, buffersend.Length); There is no need to new up an array just to replace it with the results of...
ZeroMQ pattern for multiple asynchronous requests to single endpoint
Can it be applied to asynchronous client that can talk to one single server? And could it be a good choice? REQ/REP is not recommended for traffic going over the Internet. The socket can potentially get stuck in a bad state. The DEALER/REP is for a dealer client talking...
Connect to pressure sensor using c# to get the value ,doesn't work in c#
c#,sockets,listener,tcpclient,tcpserver
In your screenshots, PC is a master device (it opens a listening server socket), and the sensor is a slave. While your code assumes, that PC tries to connect to a sensor as a client. The minimal code snippet is this: var listener = new TcpListener(IPAddress.Any, 3000); listener.Start(); using (var...
C: Linux to Windows: Sending text file over TCP produces not exact copy on the Windows side
When sending, you're assuming the data is null terminated: if((send(sockfd, buf, strlen(buf), 0)) < 0){ You should use the count actually returned by the read method, and you shouldn't use fgets() for that purpose. Your receive loop makes no sense. You're calling recv() several times and testing the result...
Sending files in socket programming tcp
Disagree with Galik. Better not to use strcat, strncat, or anything but the intended output buffer. TCP is knda fun. You never really know how much data you are going to get, but you will get it or an error. This will read up to MAX bytes at a time....
Python sending a file over sockets
The argument to socket.recv() is the maximum number of bytes that the call will return, and there's no guarantee that you'll actually get that many on any given call: while file_size > 0: work_file = server.recv(1024) f.write(work_file) file_size -= 1024 print file_size If you receive fewer than 1024 bytes on...
Socket.IO message doesn't update Angular variable
javascript,angularjs,node.js,sockets
You need to wrap the change of the model (changing properties on the $scope), with $scope.$apply(function() {}) in order to to update the view. var container = angular.module("AdminApp", []); container.controller("StatsController", function($scope) { var socket = io.connect(); socket.on('message', function (msg) { console.log(msg); $scope.$apply(function() { $scope.frontEnd = msg; }); }); }); $apply()...
Java Restart a Socket
Try closing input and output stream on the client side. client = new Socket(serverIPString,Integer.parseInt(serverPortString)); InputStream in = client.getInputStream(); OutputStream out = client.getOutPutStream(); //Do your work with input and output stream..... in.close(); out.close(); ...
How is Ctrl+C key behaves in a TCP connection
There's no such thing as sending a signal over TCP. Ctrl+C is a terminal generated signal. Assuming you (or the running process) didn't change the terminal's settings, this means that the terminal driver transforms the Ctrl+C key combination into a kill(x, SIGINT), where x is the process group ID of...
Sending a Mat object over socket from Java to Java
What I think is to Save Mat using FileStorage class using JNI. The following code can be used to save Mat as File Storage FileStorage storage("image.xml", FileStorage::WRITE); storage << "img" << mat; storage.release(); Then send the file using Socket and then retrive Mat back from File. FileStorage fs("image.xml", FileStorage::READ); Mat...
socket io get id of the disconnected socket
node.js,sockets,session-variables
Try this: io.sockets.on('connection', function(socket){ console.log("Connected Socket = " + socket.id) socket.on('disconnect', function(){ console.log("Disconnected Socket = " + socket.id); } } Let me know if that works. EDIT1: Essentially what you were doing was wrong, logically. The callback function associated to a connection was executed after somebody connected, and therefore lost,...
Socket don't save values in list
java,multithreading,sockets,arraylist
This happens because you try to read twice from the data stream by calling inData.readUTF() method. First call successfully reads data from the stream, but instead of saving result you try to perform another read 2 lines below. readUTF() is blocking method and thus it waits for another portion of...
Should I use different WSAOVERLAPPED struct for WSASend and WSARecv?
windows,sockets,winsock,winsock2
If you are using event handle (a member of the WSAOVERLAPPED structure) you should definitely use two different structures for sending and receiving.
Python 3.4 listening to selected server and port
You could try setting the timeout for the socket should fit your requirement if I understand correctly that you just need to wait one time for 20 seconds. s.settimeout(20) reply = s.recv(4096) Python Socket settimeout() However you are not guaranteed to get all the data packets delivered at once. So...
Nodejs connect mysql socket to another host?
Remove the (undocumented?) _socket option and change the host value: var client = mysql.createClient({ user: '(your user here)', password: '(your password here)', host: '192.168.12.166', port: '3306' }); However, this assumes that the MySQL database on 192.168.12.166 is configured to accept TCP connections (see the answer to this question on how...
why do I need to update nfds in select call when I remove fds from master set?
You could just set fdMax to the maximum file descriptor value supported by your system (which may be represented by FD_SETSIZE), and not worry about it, but it may cause inefficiencies. select will use the fdMax value as a hint of when it can stop its linear scan of the...
Multiple socket connection
Yes you can create multiple sockets in order to communicate with clients concurrently. See associated links for sample code. Whether or not your application will be a client or a server will depend on how the price checker expects to be communicated with. To make your life easier, focus on...
ipv6 python sockets not working
The problem is that your server is listening on localhost ::1 but you are trying to connect to 2015:cc00:bb00:aa00::2 which is a different Interface. Try setting HOST = "::" in your server in order to have it bind to all interfaces.
Moving a SIte from Drupal to Raw PHP … Error: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
php,mysql,sockets,drupal,drupal-7
Check whether mysql is running with the following command: mysqladmin -u root -p status And if not try changing your permission to mysql folder. If you are working locally, you can try: sudo chmod -R 755 /var/lib/mysql/ Reference Connect to Server...
Socket listener in IntentService
android,sockets,android-broadcast,android-intentservice
IntentService is the wrong choice for this behaviour. You should use a regular Service and manage the threads and connections yourself. You can then send data from an Activity to the Service either by calling startService() with an Intent containing the data, or you can have your Activity bind to...
Python SimpleXMLRPCServer : Socket Error , Connection Refused
python,sockets,xmlrpclib,simplexmlrpcserver
Try binding the server to 0.0.0.0 rather than localhost... server = SimpleXMLRPCServer(('0.0.0.0', 9000), logRequests=True) ...
What could cause a Java TCP socket to close?
Typically the things that cause a socket to close are: the client closes the socket the server closes the socket, possibly due to a timeout the server shuts down and issues a reset, either before shutdown or after restart, which closes the socket a firewall times the connection out and...
How to choose zmq maximum buffer size properly?
Inital note: ZeroMQ buffers & High-watermark(s) for cross-platform code Well besides both of your original questions, there is one more to be aware of. Buffers and High-Watermark mechanics may be different due to different versions of ZeroMQ-libraries. For example: a unix-based grid-computing service uses the most recent ZeroMQ version both...
Coverity - overrun of struct type
inet_addr() returns an in_addr_t, not an u_long. struct sockaddr_in's sin_addr is a struct in_addr, which holds an in_addr_t s_addr. This should do the trick: static struct sockaddr_in remote_server; remote_server.sin_addr.s_addr = inet_addr(remote_servername); ...
Find method contents from a method in superclass? (Java/Eclipse)
No, it isn't possible in Java. Because, you can not modify the return type of a function you override. The Java Tutorials Overriding and Hiding Methods says (in part) An instance method in a subclass with the same signature (name, plus the number and the type of its parameters) and...
Message Ordering with Asynchronous I/O (epoll)
I think using a buffer per connection would be OK in your case. It may however be more elegant to create a buffer per incomplete message. That would mean that you somehow have to know when your message is done, so you would need a small protocol, such as using...
Java read bytes from Socket on Linux
linux,windows,sockets,network-programming,raspberry-pi
InputStream input = client.getInputStream(); BufferedReader in = new BufferedReader(new InputStreamReader(input)); Your problem is here. You can't use multiple inputs on a socket when one or more of them is buffered. The buffered input stream/reader will read-ahead and 'steal' data from the other stream. You need to change your protocol so...
My simple client crash everytime it tries to connect to my python socket server
python,sockets,python-3.x,serversocket
There are two issues in your server/client programs. You server has two accept() calls, before the while loop and inside the while loop , this causes the server to actually wait for two connections before it can start receiving any messages from any client. The socket.sendall() function takes in bytes...
Authentication in Socket.io
Try using disconnect method from the socket object, something like this: io.on('connection', function(socket){ //temp delete socket socket.disconnect(); console.log(io.sockets.connected); socket.emit("test"); }); UPDATE: For example if your HTTP server gives to a client a token: app.post('/api/users', function (req, res) { var user = { username: req.body.username }; var token = jwt.sign(user, secret,...
The requested address is not valid in its context when i try to listen a port
Use IPAddress.Any to listen. This seems to be your goal: //listen on all local addresses The listening address you have specified is invalid for some reason. There is no need to specify a numeric address....
Jetty Web Socket Timeout
javascript,sockets,websocket,jetty
From client side you are connecting to some web socket. If port (9995 in your case) is available to connect to then it means that some program (in server mode) is listening and responding. And does something - answers with some data. So, you can connect to such program if...
Implicitly linked C Program is not connecting to localhost
Motoko, please grab C language book and check operations priority. And do it regulary, even experienced developers make errors here. And don't write this crazy style, please learn how to write for humans: if (sfd = socket(family, SOCK_STREAM, 0) < 0) return 1; You should instead do something like this:...
Mixing Java NIO with IO input streams read operation
No. You can only use streams on the channel socket if the channel is in blocking mode, in which case you wouldn't have a SelectionKey.
Only one usage of each socket address (protocol/network address/port) is normally permitted in c#
It looks like you are trying to open the port each time just to block the application until data is available. Do not try reopening the port. instead let the read function do the waiting Best way to wait for TcpClient data to become available? byte[] reap = new byte[2048];...
Exception in opening a socket at my IP address
IPAddress hostIPAddress = IPAddress.Parse("178.189.27.85"); Is your computer actually on the public internet? I would expect your computer to have a private IP (eg 192.168.x.y, 172.16-32.x.y, 10.x.y.z) unless it is directly connected to your internet connection. Assuming you're on Windows, use a Command Prompt and run ipconfig, or visit Control Panel...
How to secure blueprint access in Sails.js
javascript,node.js,sockets,sails.js
Correct me if I misunderstood something but I think your logic is wrong. I assume Bill is also an account, but when you add only his name you don't have any connection with his account information and also can identify him only by a name. In order to have some...
Can not connect to an abstract unix socket in python
python,c++,sockets,unix,unix-domain-sockets
Your C++ doesn't do quite what you think it does. This line: strncpy(addr.sun_path, UD_SOCKET_PATH, sizeof(addr.sun_path)-1); Copies a single null character '\0' into addr.sun_path. Note this line in the manpage for strncpy(): If the length of src is less than n, strncpy() writes additional null bytes to dest to ensure that...
can we open an UDP conection in javascript
No, it is not possible. Websocket connections are an 'upgrade' based on HTTP, an HTTP is based on TCP/IP. So, inherently, you cannot open a UDP connection, since for even getting a websocket connection started, you will already have a TCP/IP connection going. However, if you really do need UDP,...
Are the C functions recvfrom and sendto mutually exclusive?
c,linux,sockets,udp,thread-safety
Are the C functions recvfrom and sendto mutually exclusive? No. They can both be executed by different threads at the same time. sendto() doesn't wait for recvfrom() to read the data. It would place the data into the socket's buffer and return. Multiple sendto() may block for the previous...
ZMQ: No subscription message on XPUB socket for multiple subscribers (Last Value Caching pattern)
python,sockets,proxy,zeromq,publish-subscribe
I found the solution for this problem, and even though I read the docs front to back and back to front, I had not seen it. The key is XPUB_VERBOSE. Add this line to after the backend initialisation and everything works fine backend.setsockopt(zmq.XPUB_VERBOSE, True) Here's an extract from the official...
How to catch socket exceptions on TcpInboundGateway?
java,spring,sockets,spring-integration
We should probably change that to propagate the exception, but it would be a behavior change so we'd probably have to do it in 4.2 only, unless we make it an option. Actually, after further review; this can't be accommodated - you have to handle the exception via the connection...
Creating Multi-user chat with sockets on python, how to handle the departure of the server?
could you make your server log for heartbeats? and also post heartbeats to the clients on the socket? if so, have a monitor check for the server heartbeats and restart the server application if the heartbeats exceed the threshold value. also, check for heartbeats on the client and reestablish connection...
websockets - reject a socket connection
You can either use socket.close() or socket.terminate() to close the connection.
C++ Winsock programming, receiving no response from HTTP protocol
The HTTP protocol requires all header lines to be ended with CRLF and an empty line to follow. You have all header lines without any line breaks. char message[] = "GET http://www.nasa.gov/index.html HTTP/1.1" "Host: www.nasa.gov" "Accept: */*" "Accept-Language: en-us" "Connection: keep-alive" "User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"; This...
Does FD_ISSET() return the file descriptor which received data
From the POSIX standards reference page on select: FD_ISSET(fd, fdsetp) shall evaluate to non-zero if the file descriptor fd is a member of the set pointed to by fdsetp, and shall evaluate to zero otherwise. So exactly what the result of FD_ISSET (which is really not a function but a...
Sails.js sockets. Good and bad sides. Difference with socket.io
javascript,node.js,sockets,socket.io,sails.js
Sails.js sockets use socket.io under the hood. They are merely a "lightweight wrapper" around socket.io connections.
C++ overload << operator for class object acting as stream
For your function to work at all, you'll need to use references to TcpSocket for the input argument as well as the return type. Also val needs to be T const&, not T&. template<typename T> TcpSocket& operator<<(TcpSocket& sock, T const&val) { unsigned char bytesOfVal[] = //parse bytes of val here......
What type of database is the best for storing array or object like data [on hold]
Redis would probably be fastest, especially if you don't need a durability guarantee - most of the game can be played out using Redis' in-memory datastore, which is probably gonna be faster than writing to any disk in the world. Perhaps periodically, you can write the "entire game" to disk....
Unable to receive data after connection getting Bad file Descriptor error
c,linux,multithreading,sockets
(The issue you observe has nothing to do with running on a dual-boot machine.) The code as shown introduces a race by using the address of the same variable for each incoming connection to pass the socket descriptor to the thread function. The race occures if accept() would return faster...
Chrome UDP sockets not receiving from remote machine
javascript,sockets,google-chrome,udp,google-chrome-app
François Beaufort's now deleted answer provided a useful suggestion, sadly in a way that was more appropriate for a comment. I'm making this a community wiki so that he does not feel robbed of reputation. The HOST part indicates which interface you're listening on for data. Setting it to 127.0.0.1...
No transports available
Oddly enough starting a new project from scratch using the react-native-cli generator I was able to copy and paste all of my components over to the new project and have everything work perfectly. I am not sure where the problem is but I will assume for now that there is...
Python3:socket:TypeError: unsupported operand type(s) for %: 'bytes' and 'bytes'
Normal string formatting cannot be used for bytes. I think the way to go about it is - you'd have to first generate a string, format it and then convert it to bytes with appropriate encoding. So the following changes should work change sock.send(b'Hello %s!' % data) to reply =...
Ping a server without freezing the Thread
What exactly did you want to got in try { tt.join(); } catch (InterruptedException e) { tt.stop(); } block? Here you joined to parallel thread and waits till this thread will ends (got ping result). You have next options: Wait till ping ends Don't wait... and don't got result Use...
cloudflare SSH and sockets: how to run them together?
CloudFlare can't proxy websockets right now for anyone other than an Enterprise customer (we're rolling out broader support later this year). Unless it is going over one of these ports we supportright now, then it needs to be on a subdomain we don't touch (this would also mean the SSL...
Making socket communication using bin_prot
Well, bin_prot is just a serialization protocol, and doesn't depend on whatever you're using for a transport layer. Basically, to serialize a value to string, you can use Binable.to_string function (or Binable.to_bigstring). It accepts a packed module. For example, to serialize a set of ints, do the following: let str...
Haxe server-client exchange on all platforms
sockets,websocket,client,server,haxe
What you are looking for is Haxe Remoting, which is part of the Standard Library Haxe remoting is a way to communicate between different platforms. With Haxe remoting, applications can transmit data transparently, send data and call methods between server and client side. relevant sources: http://haxe.org/manual/std-remoting.html http://api.haxe.org/haxe/remoting/ As side note,...
Mysterious number of chars read with read() in simple chat in C?
while sending data from server you must be typing Hello then pressing ENTER key which is nothing but \r\n. So client is reading it as Hello\r\n. So you must be getting two characters extra. I hope it works for you. You can check this by looping through input buffer and...
Refactor an IO recursive loop into a monad folding in Haskell
sockets,haskell,network-programming,io-monad
The idiomatic way to repeat the same action over and over again forever is forever serverLoop :: Socket -> IO () serverLoop sock = forever $ do (conn, _) <- accept sock forkIO $ handleConn conn ...
Handling Keyboard Interrupts
sockets,exception-handling,sml,smlnj,keyboardinterrupt
You've hit a pretty big limitation with Standard ML per se, which is that the standard language does not make any provisions for concurrent programming. And you need concurrency in this particular case. Luckily, you're using SML/NJ, which has some extensions that allow concurrency support — continuations. In SML/NJ, you...
Closed system shellcode experimentation (segfault)
c,sockets,segmentation-fault,shellcode,experimental-design
This doesn't work because shellcode file is an object file. It is an intermediate file format meant for linker consumption. Treating it as a sequence of instructions is plain wrong. Object file contains code, among other things. However this code is incomplete. When a code references a symbol, like write,...
When BSD socket reports that RST was received, if not everything was read yet
Will the first call to send() return an ECONNRESET? Not unless it blocks for long enough for the peer to detect the incoming packet for the broken connection and return an RST. Most of the time, send will just buffer the data and return. will the next call to...
Using sockets to build real time chat for iOS?
ios,objective-c,sockets,chat,real-time
Assuming you've got your server side things setup, you can use Square's Socket Rocket to implement the client side https://github.com/square/SocketRocket If you're using socket.io at the backend, there are plenty of iOS libraries available for those as well. SIOSocket is one such library....
Handling POST request via Socket in Java
java,sockets,http,post,request
The code you have shown is not the correct way to read HTTP requests. First off, Java has its own HttpServer and HttpsServer classes. You should consider using them. Otherwise, you have to implement the HTTP protocol manually. You need to read the input line-by-line until you reach an empty...
Reading packets from a client stops after 1 or 2 received
The while (alreadyread != 5) seems extraneous since alreadyread will be 5 or nowread will be less than 0 after the do-while, and if nowread is less than 0 you exit. You've poorly defined a command, I think we need more information on that. It looks like you're getting a...
Communicating between a PC and UR5 Universal Robotics Robot Arm using TCP/IP LabVIEW
sockets,networking,tcp,labview,robotics
A couple of points: Did you get the provided desktop GUI working? That's always the first step. The pic is helpful, but we need to know what you are trying to send (i.e. the data). What you are trying to send should be a command from what I called the...
Sockets make no sense?
The client doesn't get to cause arbitrary events to fire on the socket. It is always a message event. Using the same client, try this server code in your connection handler: socket.on('message', function(data) { // data === "pressed", since that's what the client sent console.log("Pressed!"); socket.close(); }); ...
Linux local communication sockets: Why is bind() not failing as expected?
Because: unlink(TS_SERVER); You remove the existing socket file, which allows a new one to be created in its place....
Sending image from client on java to server on python
java,python,mysql,sockets,server
I can't see that you sending image size before sending the image, but in Python code you're reading 4 bytes image size first. You need to add sending of image size in your Java code: try { OutputStream outputStream = client.socket.getOutputStream(); ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); ImageIO.write(bufferedImage, "png", byteArrayOutputStream); //...
Do I need a queue for a socket pair pattern?
This depends on how exactly write_message and on_message are defined. For many protocols implemented on top of the Tornado IOStream including Tornado's WebSocketHandler, a queue would not be necessary for a 1:1 pairing because IOStream.write has an internal FIFO buffer and so individual writes are atomic. However, if write_message internally...
C sockets: Exit client after all data is received
Your server should close the socket after the whole file content has been sent. This would cause your recv function to return zero and end the client's receive loop. If you want to keep the connection for some reason, then you would need to send some additional information to the...
recv function always gives me the same buffer
while(getline(ss, tok, ',') && i < 16 ){ matrix[i] = static_cast<float>(::atof(tok.c_str())); i++ ; } Since you never reset i, matrix will never be updated after the first time. The recv is fine....
Popen.subprocess in threads
python,multithreading,sockets,popen
The issue could be that some exception is getting thrown before the process can close the connection. You should try the below suggestion and check if that is the case. You should make it a habit to write the code to close connections in a finally block, something like -...
UDP and TCP always use same IP for one client?
python,sockets,networking,tcp,udp
Answering your last question: no. Because: If client is behind NAT, and the gateway (with NAT) has more than one IP, every connection can be seen by you as connection from different IP. Another problem is when few different clients that are behind the same NAT will connect with your...
How to identify a client connected to AF_UNIX socket?
For UNIX Sockets; socket.acept() will return socket, (). i.e: An empty tuple. You can get some information about the "client" socket by looking at socket.fileno() for example. For example with a modified echoserverunix.py: $ python examples/echoserverunix.py <registered[*] (<Debugger/* 19377:MainThread (queued=0) [S]>, <EchoServer/server 19377:MainThread (queued=2) [R]> )> <started[server] (<EchoServer/server 19377:MainThread (queued=1)...
Merging socket request/response in a function
The simple solution is to ignore the generic parameter when adding the Promise to the dictionary. This can easily be done by either inheritance or interfaces, depending on your needs (for example, Task<T> inherits from Task). Unlike Java, you can't simply use Promise<?> like you're trying to. For example: public...
Why specify a host when creating a socket server in Python?
An obvious example is the case of running a service on a multihomed machine. Maybe you want a different key for the sshd on each ip address. Or totally different web servers all listening on port 80 but different addresses. You get the idea. I can't see why it would...
How to build Linux kernel to support SO_ATTACH_BPF socket option?
c,linux,sockets,linux-kernel,bpf
In my setup, which is based on Fedora 21, I use very similar steps to those you linked to compile and install the latest kernel. As an additional step, I will do the following from the kernel build tree to install the kernel header files into /usr/local/include: sudo make INSTALL_HDR_PATH=/usr/local...
psuedo TCP multicast with os.dup2() in python?
python,sockets,tcp,multicast,dup2
After os.dup2() call both file descriptors (FDs) refer to the same socket, thus sharing its buffers. When data is extracted (via recv() or read()) using original FD, this fragment can no longer be extracted using duplicated FD, and vice versa. Each octet of incoming data will be read exactly once...
Socket c++: recv function returns -1
Many errors in the C++ code - like if (bytesSent = 0), which is an assignment with result cast to boolean, so always returning false. You don't pay attention to number of bytes read from a TCP socket, assuming that you receive one complete message as you sent it -...
Java socket receives byte array where each byte is 0
Mixing binary and text modes on the same stream is tricky. You would be advised not to do it. Using DataInputStream (for the name, count and file content) is one possible solution. (And that is what I would try). Another would be to encode the file content as text (e.g....
Is TcpClient a single connection use? How do I send a second message?
Everyone that said not to close the stream was right. The reason I kept closing the stream was because the receiving software would then process my message. But the receiving software would also process my message if it was wrapped in the ASCII "STX" and "ETX" characters. My ultimate problem...
PHP/Java socket communication not working
See: http://php.net/manual/en/function.socket-recv.php The MSG_WAITALL flag will block until it has received the full length of the buffer. Which you have specified as 2048 bytes of data....