Programmer Group

preface sed (Stream EDitor) is a powerful and simple text parsing and conversion tool. It can read the text, edit the text content (delete, replace, add, move, etc.) according to the specified conditions, and finally output all lines or only some lines processed. sed can also realize quite complex text processing operations without inter ...

Introduction to file system (FS) File system composition ① File system interface ② Software collection for object management ③ Object and attribute File system role From the perspective of system, file system is a system that organizes and allocates the space of file storage device, is responsible for file storage, and protects and retri ...

1.shell: command parser. When entering a command in the terminal, it will be parsed by the shell and execute an executable file with the same name. You can view which shells the current system supports through cat /etc/shells. Use echo $SHELL. Shell is the environment variable $is the value of the environment variable to view the command parser ...

1. Download MariaDB database 1.1 test: whether the current virtual machine can correctly link to the Internet. ping www.baidu.com is used here for testing. 2. Installation method: 1. Command to install database:   yum   install mariadb-server            Install MariaDB databas ...

Linux Notes Installation section: swap virtual memory is twice as large as memory, such as 4G (no setting if large) Boot partition master boot 500M /Root Full Allocation You can also create a / data that can be used to mount things -------------- Configuration section: hostnamectl set-hostname name #Set Host Name exec bash #Refresh Remo ...

Processes, Threads, Programs A process is the smallest unit of the system for resource allocation and scheduling. It is an instance of program execution. A running program is also a container for threads. Threads are the smallest units that the operating system can schedule operations. They are the actual units of operation in a process, and ...

System Administration Troubleshooting Running out of Memory Ram: the data being used, such as 2 + 2 = 4, the 2 + 2 process is stored in RAM SWAP: a 100g hard disk, express 4G, is sent out to SWAP. It can be used when there is not enough Memory. Its function is the same as that of stand by Cache: the cache is used in conjunction with the CPU. ...

The earliest examples of this paragraph were found online because of the continuous use of shared memory and memory mapping, and then changed to meet our needs, but the underlying differences and connections were not considered. Today, because the data sharing libraries being tested for the Cognitive Framework involve shared memory, colleagues ...

I. Boot-up process of Linux system 1.1. Start-up self-test (BIOS) Start-up self-check (BIOS): After the server host is powered on, CPU, memory, graphics card, keyboard and other devices will be initially detected according to the settings in the motherboard BIOS. After successful detection, system control will be transferred according t ...

RF24 project code analysis Header file https://github.com/nRF24/RF24/blob/master/RF24.hSource file https://github.com/nRF24/RF24/blob/master/RF24.cppData stream sending / receiving example https://github.com/nRF24/RF24/blob/master/examples_linux/streamingData.cpp Function bool writeFast(const void* buf, uint8_t len) This function makes full ...