Networking and Programming in One

Have you ever needed to replace some text in a file really quickly? Then you have to open up your text editor, find the line, and then type out your replacement. What if you have to do that many times? What if it isn’t also exactly the same thing and you have to run multiple searches and replace each occurrence? It gets tedious very quickly, but there’s a better way of doing it with a tool called sed. We’ve written about POSIX and went over some of the interfaces and utilities a system must provide in order to be POSIX compliant. The command line tool sed is one of those utilities that provide a feature-rich way to filter, find, substitute, and rearrange data in texts files. It is an extremely powerful tool that is very easy to get started with, but very difficult to learn through and through due to its seemingly endless number of features. First, we should note that the GNU implementation of sed, while POSIX compliant, goes above and beyond the specification to provide exte...

First install the proftpd app with the command "apt-get install proftpd", then hit enter. Then you will see 2 options for running applications proftpd in inetd or standalone mode. Inetd and standalone difference is when an ftp server accessed only occasionally or accessing a bit with the reasons for saving resources / memory. If an ftp server accessible continuously and many users accessing select standalone mode. After the installation is complete, check whether proftpd is running or not with the command "nmap localhost". If nmap has not been installed, install "apt-get install nmap" first. If port 21 exists, then the ftp server is already running. Then, test the ftp server from the client, use the command "ftp 10.252.108.44". Then enter the user name on the server, do not forget to enter the password as well. In this case i use user "student". Once logged in on the ftp server, type the command "ls" to fi...

The Seven OSI Layer 7 OSI Layer is a network architectural model developed by the International Organization for Standardization (ISO) body in Europe in 1977. OSI has an extension, namely: Open System Inter Connection which is a collection of Layers that are not interdependent but are related to each other Others, the intent of the statement is that each Layer already has their respective Duties and Responsibilities and Mutual Fill each other, and the same as a Group cooperation. Seven OSI Layer has 2 levels layer Function of each Layer Physical Layers  : Functions for determining network transmission media, signaling methods, bit synchronization, network architecture, network topology and cabling. Devices that can be connected with the Physical layer are the NIC (Network Interface Card) and the cables. DataLink Layer : This works to determine how data bits are grouped into a format called frames. In this Layer there are error correction, flow c...

HTTP (Hypertext Transfer Protocol) HT TP (Hypertext Transfer Protocol) is a protocol used by WWW (World Wide Web). HTTP defines how a message can be formatted and sent from server to client. HTTP also controls what actions to be taken by web servers and web browsers in response to commands in this HTTP protocol. The problem with HTTP is that communication is not fully secure. Information we send to websites such as contact information can be easily retrieved by third parties. For example, it is not advisable to transact on the Internet and banking affairs, as the packets sent using this protocol are not encrypted, so they are considered less secure. A session on HTTP is a sequence of request transactions and a network response by using the HTTP protocol. An HTTP client will start a request. The client will open a Transmission Control Protocol (TCP) connection to a specified port on a host (usually port 80 or 8080) server listening on port 80 will wait for client reques...

After successfully installing Linux, you are actually required to update Linux system files. But it can be done as you wish, when, where, is up to you. 1. Check For Update Now that we've added all those new sources, even if they've already popped up of their own accord. sudo apt-get update 2. Upgrade Packages Now that we have finished adding things to get updates from and secured them, it's time to update what you already have. sudo apt-get upgrade 3. Major Upgrades Some updates are bigger than others. This command is for the huge ones. sudo apt-get dist-upgrade 4. install the media player Some linux distro already installed media player but less than maximum. So install some of these media players. sudo apt-get install smplayer vlc So when you are connected to the internet, do not forget to run the above command. But if it's not done it's okay, it all depends on you.