Shell

With "'"""todayis" ' date ' preceded by a character, followed by ' date ' Represents the Execute Date command. PDATE=""'date'is Date" Expr " is used to calculate the result of a=9b=tenvar1= $a +$becho $var 1 output is "9 +10"expr" is used

Shell types: Bourne shell, Bourne Again shell, C shell, Korn shell, Perl shell Users can choose their favorite shell (specified when the system administrator creates an account for the user), and in the last field of the/etc/passwd file, you can

First, IntroductionThe shell is the command-line interpreter that the user interacts with the operating system.There are many kinds of shells:bash, csh, sh, ksh 、、、The command line we saw when we waited for Linux was a bash.Two, the first

File D.txt The following contentGGG 1portals:192.168.5.41:3260Werew 2portals:192.168.5.43:3260How to change the file D.txt content to the following contentGGG 192.168.5.41:3260Werew 192.168.5.43:3260Problem Solving Ideas:[[email protected] study]#

Please put the following stringstu494e222fstu495Bedf3stu49692236stu49749b91Switch to the following form:stu494=e222fStu495=bedf3stu496=92236Stu497=49b91Question 2:Echo I am Oldboy training, please put the output of each character to the order,

The file file2 content is as follows:0 Qwert1 ASDFGHJK2 ASDJKL2 zxcvbn3 Dfghjkll4 222224 TYUIOP4 BNMMake the first column equal to one row, not the first column, that is, the following format:22222;tyuiop;bnmQwertAsdfghjkAsdjkl;zxcvbnDfghjkllThe

Tag: set command; unset commandFor example: There are now two user-defined variablesName= "Andy Lau"Age=20The set command is used to view variables650) this.width=650; "Src=" Http://s5.51cto.com/wyfs02/M01/87/EF/wKioL1fkk0CQqSUwAADT1GLzRuI190.png-wh_

Stop it:#!/bin/bashPid= ' Ps-ef|grep/opt/lampp|grep-v Grep|awk ' {print $} ' |wc-l 'B=0If [$pid-gt $b]ThenPs-ef|grep/opt/lampp|grep-v Grep|awk ' {print $} ' |xargs kill-9echo "LAMMP has stopped!"Elseecho "LAMMP is not running!"FiStart:#!/bin/bashPid=

1. Exclude portions of files from disk usage statisticsDu--exclude "*.iso" dir2. Find the maximum of 10 files in a specified directoryFind-type f-exec du-k {} \ |sort-nrk 1 |head-n 103. List the maximum 10 commands for the current systemCat.

Software Name: Upx3.03+upolyx.5 Shell v1.0 Chinese Green Editionsoftware Category: Chinese softwareOperating Environment: Windowssoftware language: Simplified ChineseLicensing method: free versionFile Size:635 KBSoftware level:Finishing Time:2012-10-

1. Crontrab for Linux in the projectScheduled execution under Linux is mostly done using a custom plan in the crontab file, but it's not very complex, and it's basically remembered once and for all, and the key is to remember the/var/spool/cron

There is no direct command in the bash shell to determine whether a variable is a pure number, then we are using an indirect method:Problem Description:Read-t 30-p "Please a number:" NUMUse the Read command to accept the user from the keyboard input

First:For tar in *.tar.gz; Do tar xvf $tar; DoneFor tar in *.tar.bz2; Do tar xvf $tar; DoneSecond: Bulk unzip all tar.gz files in a folder with the tar commandLS *.tar.gz | Xargs-n1 Tar XZVFThird: find-maxdepth 1-name "*.gz" |xargs-i tar xvzf {}This

Programming languages are generally divided into static languages and dynamic languages.Static language: Compiled language strongly typed (variable) pre-compiledExample: C C + + Java C #Dynamic language: Interpreted language weak type (default

Dynamic language: Interpreted language, is a weak type of language, Characteristics: Edge interpretation edge execution. Example: PHP, SHELL, Python, PerlWeak: variable time declaration, or even type-insensitive.Strong: Variables must be declared

A type command is provided in the Linux command to see whether the system commands are built-in or external:650) this.width=650; "Src=" Http://s4.51cto.com/wyfs02/M02/87/5C/wKiom1fePj-hZmqXAACtHTQFAN0922.png-wh_500x0-wm_3 -wmp_4-s_2639269358.png

A 9x9 multiplication table was written with a shell script, for reference only! Text below ...650) this.width=650; "src=" Http://s1.51cto.com/wyfs02/M01/87/53/wKiom1fc_6mT0-TPAABEz2kbGyk527.png "title=" 99.PNG "alt="

What is a shell?The shell itself is a C language program, it is the user use Unix/linux Bridge, most of the user's work is done through the shellThe shell has two ways of executing commands:Interactive (Interactive): Explains the execution of a user'

Memory utilization as above = "-/+buffers/cache:used"/"mem:total" = 6293404/16333656For the free command, the following formula is available:Total = used + Free;(-buffers/cache) used = mem:used-mem:buffers-mem:cached;(-buffers/cache) used=

　New Peanut Shell has a leading dynamic analysis technology, the software speed, security, stability, and has a reputation and brand double protection, with 12 million users, is the world's largest number of users dynamic domain name resolution. 　　1,