network-programming

问题 first - it's not a question of "how to bind to port of another software". now, i have a client-server app, based on TCP and i'd like to make it UDP, but i'm missing something.. i have 2 rules (which i put) to this app: 1) the "server" can stay behind router without any port forwarding configuration. 2) the "client" can listen to only one port. in TCP i do it like this: 1) the server opens initial connection to the client on port X. 2) when the client wants to open communication channel to the

问题 I am using GNU Radio to stream RF data out using a UDP sink. The data is streamed to a controlling program. As part of this process I am frequency shifting (with a multiply block), filtering and down sampling. I would like to change the values of frequency shift at run time. Is there a way for me to have values from a UDP source saved directly to a variable? The only solution I can think of now is to forever generate a sine wave and then pipe that into GNU Radio, and then multiply my signal

问题 Edit: This question is not necessary, as the WSASend() function can inherently be used in a blocking mode, even if the socket has the overlapped attribute and is associated with a completion port. To use it in a blocking mode: just don't supply an overlapped structure or a completion routine when calling WSASend() . I want to make sure that when I send data, the function will only return when this data has been placed in the send buffer. So this is what I come up with (pseudo code): void

问题 I have a server client application that I am currently working on. The server is receiving data fine over a WAN and the client seems to receive the data, but the client is only receiving one communication. Is there anything over a WAN that would make a client always only receive the first return UDP communication and none of the subsequent. Thanks for the help. Client UDP Listening code private void receiveUDP() { System.Net.IPEndPoint test = new System.Net.IPEndPoint(System.Net.IPAddress.Any

问题 I trying get text data from internet with C++ but I couldn't find anything useful. like python; import urllib data = urllib.urlopen("examplesite.com/data.txt").read() 回答1: Take a look at libcurl. It is a C library, with C++ bindings. The libcurl website includes a collection of examples in C, including one that copies a URL to a block of memory, getinmemory.c For C++, the main page of the curlcpp binding at https://github.com/JosephP91/curlcpp shows an example of downloading a URL to a file.

问题 Here is my code: package main import ( "fmt" "net" ) func main() { addr, _ := net.ResolveTCPAddr("tcp", "127.0.0.1:8081") listener, _ := net.ListenTCP("tcp", addr) fmt.Printf("listener addr: %s\n", listener.Addr().String()) for { conn, err := listener.AcceptTCP() if err != nil { // handle error fmt.Println("err") return } go handleConnection(conn) } } func handleConnection(conn *net.TCPConn) { fmt.Printf("conn addr: %s\n", conn.LocalAddr().String()) fmt.Printf("conn remote addr: %s\n", conn

问题 I need write a program on Mac OS X to manage some number of projectors on the LAN (using IP address), and I'm trying to figure out how to monitor their connection status. Something like a simple ping just to make sure I can reach them. I've tried using the NSURLRequest requestWithURL call. It worked, but the program stops responding for quite a while if any of the projectors are offline. I'm just looking to get the status and change the UI indication. Are there better ways to do this? Any

问题 I need write a program on Mac OS X to manage some number of projectors on the LAN (using IP address), and I'm trying to figure out how to monitor their connection status. Something like a simple ping just to make sure I can reach them. I've tried using the NSURLRequest requestWithURL call. It worked, but the program stops responding for quite a while if any of the projectors are offline. I'm just looking to get the status and change the UI indication. Are there better ways to do this? Any

问题 I want to use this batch script to add new entries into my host file automatically by using windows batch. I want to edit host file only when i m in office. I want to say like that: if(network name=='OfficeWifi') do changes... @echo off set hostspath=%windir%\System32\drivers\etc\hosts // if(network name=='OfficeWifi') echo 81.155.145.48 ns1.intranet.de >> %hostspath% exit thx for your help 回答1: You can get the network name (SSID) of the currently connected wireless network using the

问题 let's assume that I am listening a network , and I acquired some bits, but I want to know if there is a way to determine bits are encrypted ? what method or algorithm exists ? I mean if the bits are meaningless, it means encrypted but is there are more technical approach or algorithm to determine from bits let's say I have 0101010100001011001001100001001, how would you tell that if this is encrypted ? 回答1: Generally speaking, you can't. Encrypted data is, in almost all cases,