Programmer Think

preface When searching for logs on linux, if I want to find logs for a certain period of time, such as looking for logs from 8 a.m. to 2 p.m. this morning. It's not convenient to filter it directly with grep. You can use sed to find it according to time sed -n '/ start time date /, / end time date / p' all.log Find log For example, the time f ...

Java code modularization - method 1. Concept of method The purpose of Java method: modularity, reusability and simple application 2. Structure 3. Grammar public satatic int add(int a,int b,int c){ int sum = a+b+c; return sum; } public: access control characterStatic: static / /!!!int /double/void: enlarged return typeadd: na ...

linux three swordsman 1. Three swordsman application scenarios characteristiccommandscenegrepfilterThe grep command filters the fastestsedReplace, modify file content, take lineIf replacement / modification is required;Take out the content in a range (from 11:00 to 12:00)awkColumn fetching and statistical calculationTake columnComparison, com ...

1. Agent Components Components in Agent include Source, Channel, Sink. 1.1 Source The Source component can handle various types and formats of log data. Common source s in Flume: avroexecnetcatspooling directorytaildir Common CategoriesdescribeavroListen for Avro ports and receive Event s from external Avro client streamsexecExec source r ...

Linux three swordsmen awk awk description awk - pattern scanning and processing language； awk is gawk, which is more like a language and is very powerful in file processing; awk can customize variables, functions, loops, conditional statements, etc; awk judges and processes data line by line; awk usage awk command syntax Precedin ...

Let's practice printing process descriptor task_ Fields in struct The method used here is to insert the kernel module, and the method used is to traverse the process linked list 1, Task_ A preliminary interpretation of struct First, download your own source code. You can refer to my previous blog https://blog.csdn.net/weixin_45730790/article ...

1, Common parameters of camera (camera) The path of V4L2 related header files under Linux is / kernel source code directory / include/linux/videodev2.h, and V4L2 related API documents. White balance (automatic white balance AWB), color temperature, exposure (automatic exposure AE, exposure compensation EV), brightness, contrast, saturation ...

1, Experimental purpose 1. Understand the content of virtual file system in Linux 2. Learn how to write kernel modules 3. Implementation of file operation algorithm in virtual file system / proc 2, Experimental environment Centos7.9，vim 3, Experimental content Write a kernel module, add a directory hello in the / proc file system, and add a fi ...

Docker ! 1. Appearance of docker One product: development – launch two sets of environments! Application environment, application configuration! Development – O & M. Question: I can run on my computer! Service unavailable due to version update! For operation and maintenance, the test is very big? The environment configuratio ...

[experiment] package com.infuq.tmp; public class Main { public static void main(String args[]) { for (;;) { try { Thread.sleep(5000); } catch (InterruptedException e) { e.printStackTrace(); } } } } In the above code, let the JVM not exit. Let's do so ...