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file right ① Readable r ② Writable w ③ Executable x It can also be expressed in numbers: r=4, w=2, x=1. So 7=rwx ls -l //View current directory file properties The operation results are as follows: -rwxrw-r-- 1 xdq book 1 Sep 7 16:41 read.c 10 characters are used to determine different user permissions. It is divided into four parts: ...

Preface In some complex Linux maintenance tasks, a large number of repetitive inputs and interactions are time-consuming and error-prone. Writing a proper shell script program can accomplish a series of maintenance tasks in batch and automate, greatly reducing the burden of administrators. 1. An overview of Shell scripts 1. What is a ...

1, Basic concepts of threads 1,Basic concepts Threads are special processes. In the operating system, threads cannot exist independently. Threads are created by processes. A process can have multiple threads. If the process exits, the thread will also exit. 2,resources Each process has its own independent heap, stack, data segment, code se ...

There is A blog Redirection was introduced briefly, but it was very shallow at that time. Now let's get a better understanding of redirection. 1 Standard File Descriptor Linux uses a file descriptor to identify each file object. The file descriptor is a non-negative integer that uniquely identifies files opened by a session. Each process can ...

What is docker docker is a lightweight virtual machineRunning applications in linux container and open source The difference between docker and virtual machine differencecontainervirtual machineStarting speedSecond orderMinute levelOperation performanceNear native (90% running directly in the kernel)About 50% lossquantityDepending on the ...

What is SDL? SDL is actually a function library convenient for game development. SDL provides several functions to control image, sound, output and input, so that developers can develop application software across multiple platforms (Linux, Windows, Mac OS X, etc.) with the same or similar code. What's the use of learning SDL? At present, SDL ...

Active information collection Use the agent to send requests to achieve concealment, otherwise it is easy to be blocked; Use noise to submerge the real detection flow Discovery - layer 2 Discovery (arp layer): Non routable, broadcast based Control a machine, use two-tier tools, and continue to infiltrate the controlled machine as a springbo ...

Docker overview Docker is an open source tool for running applications in Linux. It is a lightweight virtual machine. It was born in 2013. Its original initiator is dotCloud company. Its design purpose is "Build, Ship and Run Any App,Anywhere", that is, through the management of the life cycle of application packaging, release ...

Common commands There are many commands in Linux. With the options of various commands, there are really thousands. How do we remember these commands? The answer is only two words: multi-purpose. We don't have many commonly used linux commands. As long as we use and practice frequently, we will master them quickly. For some uncommon commands, ...

Tuning system System administrators can adjust various device settings based on a variety of use case workloads to optimize system performance. The tuned daemon uses a tuning profile that reflects the requirements of a specific workload to apply tuning in both static and dynamic ways. Configuring the static tuning tuned daemon applies the ...