lpi linux essentials

number. Environment variables for the process:/proc/pid/environ9: Get the length of the variable: length=${#var}10: You can use $ (()), $[], and let in arithmetic operations.11: Accuracy Determination: echo "scale=2; 2*0.15 "| Bc12: Binary conversion: echo "obase=2;9999" |BC obase can be any binary (2, 8, 16, 60, etc.)13: $ $ is the first parameter, [email protected] is extended to "$", "$", "$", $* is expanded to "$1c$2c$3" C is the IFS qualifier (for example, space or:, etc.).This article is

motor, wherein the disc is composed of a sector, a track and a cylindrical surface.The operating system (Operating System,os) is actually a set of programs that focus on managing all the activities of the computer and all the hardware in the drive system.The computer is mainly in binary production units, commonly used disk capacity unit is byte, its unit conversion to 1byte=8bit.The operating system is only to drive and manage the hardware, and to use hardware, you need to through the applicati

Tags: Linux basics Lite2017/11/17 0:23:14Blog:1. Instructions for querying the Help documentation:(1) Use the type to see if the command is an external command or an internal command(2) If an external command is used, the following 3 commands are queried:Man number of chapters command: You need to first use the Whatis command to query which chapter the command belongs to, and then execute the commandsCommand --help: Directly execute this line command

peripherals and install device drivers (such as network cards)5. Familiar with the Grub/lilo guide and simple repair operation.6. Familiar with Linux file system and directory structure.7. Master Vi,gcc,gdb and other common editors, compilers, debuggers.8. Understand shell aliases, pipelines, I/O redirection, input and output, and shell scripting.9. Learn about networking in a Linux environment.The above i

Linux Technology Learning Essentials, you have mastered it---beginners must see1, how to do the embedded Linux before learning preparation?to become a qualified embedded Linux engineers need to learn the knowledge in the field of software and hardware, and need to master the development norms and principles in the begi

"alt=" Full stack prerequisite Linux Basic full Stack prerequisite Linux basic "class=" AlignCenter size-full wp-image-76939 "title=" Full stack prerequisite Linux foundation full stack prerequisite Linux basic "width=" "height=" 724 " />As far as application management is concerned, Ubuntu needs to be familiar with a

Linux Learning Essentials (reproduced from Red Union)First, the basic requirements of learning Linux1. Master at least 50 more common commands.2. Familiar with Gnome/kde and other x-windows desktop environment operation.3. Master the common installation methods for. Tgz,. RPM and other software packages4. Learn to add peripherals, install device drivers (such as network cards)5. Familiar with Grub/lilo guid

private keysSsh-keygen-t RSA (This is the case with test)Enter------------password------Confirm passwordThe first file is a private keyThe second file is a public keyUpload test's private key to Test1.Ssh-copy-idEnter the test1 passwordSuccessfully uploadedSwitch to Test1Cd. SSHLlThe private key of test was foundAt this time we use test to go to the user login test1, need to enter a password, not test1 passwordTurn fromIt Essentials

the best fit for you.The Nano shortcuts available are shown below the user interface, and the Nano has only the functionality of the most basic text editing software. It is very compact and is ideal for editing system configuration files. For those who do not need complex command-line editing capabilities, the Nano is perfectly equipped.What do you think?Here are some other editors I'd like to mention: the Nice editor (NE): The official website says: "If you have enough information, you have th

number is 1, the error output number is 2performed in the system with a normal user "Student"Find/etc-name passwdbecause the student user rights issue will have the following outputFind: '/etc/pki/ca/private ': Permission denied # # # #没有进入权力, errorFind: '/etc/pki/rsyslog ': Permission deniedFind: '/etc/audit ': Permission denied/ETC/PASSWD # # #正确输出Find/etc-name passwd > File # # # # #重定向正确输出Find/etc-name passwd 2> File # # # # # #重定向错误输出Find/etc-name passwd > File # # # # #重定向所有输出Note : 2>,>

% Echo%date% Del *%date:~4,10%-5.dmp Exp Nianjin/nianjin file=d:\temp\nianjin%date%.dmp Owner=nianjin As shown in the following: Simplified auto-Export script2. backup file geo-copy script (win copy to Linux) FTP command Script Ftp-n 192.168.226.129 FTP Command Execution content User why 123456 Cd/home/why/ftptest Bin Put Seo.pptx Bye ! The c

program calls the library in each operating system exists. system call (Library of wheat):systemcall API(Steamed bread Library): Advanced Call11. Kernel Function: Process Management Memory Management File System Network functions Hardware Drivers Security Mechanisms12, the basic principles of Linux:1, consisting of a small program with a single purpose; a combination of small procedures to complete complex tasks;2, all documents;3, try to avoid captu

/8F/A6/wKiom1jnY4uiqu_kAAAiRR3kfAg764.jpg-wh_500x0-wm_ 3-wmp_4-s_1105899805.jpg "title=" 36020170407175711659.jpg "alt=" Wkiom1jny4uiqu_kaaairr3kfag764.jpg-wh_50 "/>systemctl Set-default multi-user.target # #开机不开启图形650) this.width=650; "Src=" https://s5.51cto.com/wyfs02/M00/8F/A7/wKiom1jnY7LSheZMAAAgY1XBteo325.jpg-wh_500x0-wm_ 3-wmp_4-s_2779274314.jpg "title=" 36020170407175718927.jpg "alt=" Wkiom1jny7lshezmaaagy1xbteo325.jpg-wh_50 "/>systemctl Set-default graphical.target # #开机启动图形650) this.wid

Chown chattr lsattr PSWhoAmIView System User login Information command (6)W W.H.O.Users Lastlastlog Fingers View Hardware-related commands (6) Ethtool Mii-tool Dmidecode DMESG Lspci Other (14) ChkconfigEcho YumWatch alias UnaliasDate ClearHistoryEject TimeNohup NCXargsAdvanced Linux Command memory for monitoring physical components: Top Freevmstat mpstat iostat sarcpu:top vmstat mpstat iostat SarI/O:vmstat Mpstat iostat SAR process: IPCS IPCRM Load:U

) SIGRTMAX-2 6, Common signal 1) SIGHUP 1--suspend detection of the control process and terminal; 2) SIGINT 2--Press CTRL + C to send a signal 3) SIGKILL 9--strong kill Process 4) SIGTERM 15--default to terminate process 5) SIGTSTP 20--Press CTRL + Z to send a signal 7, kill process by process name [email protected] ~]$ Killall-9 suSu:no process killed 8, capturing and responding to a signal test trap[email protected] ~]$ Cat singlehandle.sh | Sed '/^$/d '#!/bin/bashfunction handler (){Echo Hey,

################################################: Overwrite output"Append outputSET-C: Prohibit overwriteSet +c: Turn off disable overrides################################################2>: Redirect Error overwrite2 ": redirect Error append output################################################>: Errors are correctly redirected to a file[Email protected] testcp]# ls/homes >/tmp/t1.txt ls/home>/tmp/t1.txt[Email protected] testcp]# Cat/tmp/t1.txtLS: Unable to access/homes: No file or directoryLS:

1. Print Network interface list[touch_more]# ifconfig | cut-c-10 | Tr-d ' | Tr-s ' \ n 'Eth0Lowww.qixoo.qixoo.com//cut-c-10; The first 10 characters of the output;Tr-d "; Delete all spaces;Tr-s ' \ n '; Compress repeated line breaks2. View Name server[touch_more]# cat/etc/resolv.conf# Generated by NetworkManagerDomain LocaldomainSearch LocaldomainNameServer 192.168.119.23. DNS Lookup[touch_more]# nslookup www.csdn.netserver:192.168.119.2address:192.168.119.2#53Non-authoritative Answer:Www.csdn.n