JIYIK CN >

Scp copies files between two hosts over the network, and the data is encrypted during transmission. Its underlying layer uses ssh for data transmission. And it has the same authentication mechanism and the same security level as ssh. When u...

Since we want to delete the files under the directory regularly, we need to use the Linux crontab command. And the content format of each work routine is also introduced in the format of each crontab work. Similarly, we need to use shell sc...

Compared with at , which executes a command only once, crontab, which we are going to talk about in this article, executes the set commands in a loop. Similarly, the use of crontab requires the support of the crond service. The service is s...

This article mainly involves a knowledge point, which is the atd service. Similar to this service is the crond service. The functions of these two services can be similar to the two functional functions of javascript. Those who have learned...

Usually, in Linux system we need to frequently delete some temporary files or junk files. If we delete them one by one manually, it will be quite troublesome. I have also been learning shell script programming recently, so I tried to write...

In shell script programming, predicates are often used. There are two ways to use predicates, one is to use test, and the other is to use []. Let's take a look at how to use these two methods through two simple examples. Example 1 # test –...

? is a special variable. This variable represents the return value of the previous command. That is to say, when we run certain commands, these commands will return a code after running. Generally, if the command is successfully run, the re...

In Linux, the best editor should be vim. However, the complex commands behind vim's powerful functions also make us daunted. Of course, these commands do not need to be memorized by rote. As long as you practice using vim more, you can reme...

A lot of software found today is in the tar.xz format, which is a lossless data compression file format that uses the LZMA compression algorithm. Like gzip and bzip2, it supports multiple file compression, but the convention is not to compr...

As the most commonly used web server, Apache can be used in most computer operating systems. As a free and open source Unix-like operating system, Linux and Apache are a golden pair. This article will introduce the installation and use of A...

This article is a part of the ongoing series of Awk tutorials and examples. Like any other programming language, Awk also has user-defined variables and built-in variables. In this article, let's review how to define and use awk variables....

In our previous article in the iptables firewall series, we reviewed how to iptables -A add firewall rules using . We also explained how to allow incoming SSH connections. At a high level, it involves the following 3 steps. Delete all exist...

This article explains how to iptables -A add iptables firewall rules using the (append) command. -A for appending. If it makes it easier for us to remember -A as adding rules (rather than appending rules), then that's fine. However, remembe...

The iptables firewall is used to manage packet filtering and NAT rules. iptables comes with all Linux distributions. Knowing how to set up and configure iptables will help us manage the Linux firewall effectively. The iptables tool is used...

This article is part of our ongoing series on Linux iptables. When our iptables rules are not working as expected, we may need to log the packets dropped by iptables for troubleshooting. This article explains how to log incoming and outgoin...