Memset ( & dest, 0, sizeof ( dest )); /* zero the struct */ dest. Sin_family = AF_INET; dest. S_addr = inet_addr ( '127.0.0.1' ); /* set destination IP number */ dest. Sin_port = htons ( PORTNUM ); /* set destination port number */ Now we get on to the interesting part: The first line uses memset() to zero the struct.

The second line sets the address family. This should be the same value that was passed as the first parameter to socket(); for most purposes AF_INET will serve. The third line is where we set the IP of the machine we need to connect to. The variable dest.sin_addr.s_addr is just an integer stored in Big Endian format, but we don't have to know that as the inet_addr() function will do the conversion from string into Big Endian integer for us. The fourth line sets the destination port number. The htons() function converts the port number into a Big Endian short integer. If your program is going to be run solely on machines which use Big Endian numbers as default then dest.sin_port = 21 would work just as well.

Networking and Socket programming tutorial in C.; Author: Edison Heng; Updated: 21 Aug 2014; Section: Internet / Network; Chapter: General Programming; Updated: 21. 'On its own, C# simplifies network programming. Combine it with the precise instruction found in C# Network Programming, and you'll find that building networ, ISBN.

Network programming under UNIX is relatively simple in C. This guide assumes you already have a good general idea about C, UNIX and networks. This is the very bare. Sep 28, 2010 Network Programming with C#. Can anyone give me a free reference to programming in networking using C#?

However, for portability reasons htons() should always be used. Now that all of the preliminary work is done, we can actually make the connection and use it. Len = recv ( mysocket, buffer, MAXRCVLEN, 0 ); Now this receives up to MAXRCVLEN bytes of data from the connection and stores them in the buffer string. The number of characters received is returned by recv(). It is important to note that the data received will not automatically be null terminated when stored in the buffer, so we need to do it ourselves with buffer[len] = ' 0'.

And that's about it! The next step after learning how to receive data is learning how to send it. Randall Bramblett Light Of The Night Rar on this page. If you've understood the previous section then this is quite easy.

All you have to do is use the send() function, which uses the same parameters as recv(). If in our previous example buffer had the text we wanted to send and its length was stored in len we would write send(mysocket, buffer, len, 0). Send() returns the number of bytes that were sent. It is important to remember that send(), for various reasons, may not be able to send all of the bytes, so it is important to check that its return value is equal to the number of bytes you tried to send. In most cases this can be resolved by resending the unsent data. A simple server [ ]. Struct hostent * gethostbyname ( const char * name ); This function obtains information about a domain name and stores it in a hostent struct.

The most useful part of a hostent structure is the (char**) h_addr_list field, which is a null terminated array of the IP addresses associated with that domain. The field h_addr is a pointer to the first IP address in the h_addr_list array. Returns NULL on failure.

FAQs [ ] What about stateless connections? [ ] If you don't want to exploit the properties of TCP in your program and would rather just use a UDP connection, then you can just replace SOCK_STREAM with SOCK_DGRAM in your call to socket() and use the result in the same way. It is important to remember that UDP does not guarantee delivery of packets and order of delivery, so checking is important.

If you want to exploit the properties of UDP, then you can use sendto() and recvfrom(), which operate like send() and recv() except you need to provide extra parameters specifying who you are communicating with. How do I check for errors? [ ] The functions socket(), recv() and connect() all return -1 on failure and use errno for further details.