Programmer Group

Timing Auto-Execution in Linux (at,crontab) concept In Linux systems, there are two ways to schedule work ahead of time at executes only once crontab repeats periodically Through the application of these two tools, we can realize the function of timing and automatic operation at the operating system level. Experimental environment ...

Three swordsmen Three Swordsmen of Text under linux grep egrep,grep,fgrep Text Search Needs grep: Search the text according to the pattern and display the line of text that conforms to the pattern. pattern: matching condition of combination of text characters and metacharacters of regular expressions grep [option] "pattern" file grep root ...

1 LTP Introduction and Internal Mechanisms 1.1 Introduction to LTP LTP(Linux Test Project) is an open source community cooperation project based on GPL protocol. Initiated by SGI in 2000, IBM, OSDL and Bull jointly participated. After 2001, they were jointly developed and maintained by SUSE, Fujitsu, Red Hat and Oracle. The reliability, s ...

Openssl configuration file: / etc/pki/tls/openssl.cnfThree strategies: matching, supporting and optional. Matching: refers to the requirement to fill in the application information and CA settings information must be consistent; support: refers to the need to fill in the application information; optional: refers to whether it is necessary or no ...

Using rz and sz to transfer files between Linux and Windows [root@centos01 ~]# yum install -y lrzsz # Installation Tools sz test.txt # Pop up a dialog box to pass to the selected path rz # After returning, the corresponding file is selected from the dialog box and passed to the current directory of linux Linux to Windows Windows passed to Li ...

I. shutil module Advanced File, Folder and Compressed Packet Processing Module shutil.copyfileobj(fsrc, fdst[, length])Copy the contents of a file to another file import shutil shutil.copyfileobj(open('old.xml','r'), open('new.xml', 'w')) shutil.copyfile(src, dst)Copy file shutil.copymode('f1.log', 'f2.log') #The target file must ex ...

#!/bin/bash echo -e "\\033[1;34m start make sd \\033[0m" #Getting sd card information sd_main=`ls -l /dev/disk/by-id/ | grep usb- | awk -F '/' 'NR==1{print $3}'` sd_1=`ls -l /dev/disk/by-id/ | grep usb- | awk -F '/' 'NR==2{print $3}'` sd_2=`ls -l /dev/disk/by-id/ | grep usb- | awk -F '/' 'NR==3{print $3}'` if [ -d "/de ...

AOP (Aspect Oriented Programming) is slice-oriented programming. The so-called slice-oriented programming is that the program can be divided into numerous time nodes according to time. Using the idea of AOP, other codes can be inserted into any time node to achieve their business needs. In other words, for those non-user requirements, such as ...

Catalog abstract Section 1: Differences and Relations between px4 and apm Section 2: The role of px4 and apm in each folder Section 3: Start-up process of px4 and apm UAV abstract This section mainly records the comparison documents between the code architecture of px4 and Ardupilot, welcome criticism and corre ...

This article modifies an error and adds a more detailed explanation to the article translated by Fu Huizhong (original author: Thomas Niemann). introduction Writing compilers was a very time-consuming task until 1975.This year Lesk[1975] and Johson [1975] published papers on lex and yacc.These tools greatly simplify writing compilers.Details ...