Shell

First, what is the shell?The shell is a command-line interpreter that provides users with an interface system-level program that sends a request to the Linux kernel to run the program, and the user can start, suspend, or even write some programs

Spark 1.4 was downloaded and the following error was encountered while running Spark-shell: Java.net.unknownhostexception:ukon-m-q0ep:ukon-m-q0ep:nodename nor servname provided, or not knownAt Java.net.InetAddress.getLocalHost

In practice, it is sometimes necessary to remotely start programs on other Linux hosts from the Web management interface, which can be easily met by SSH protocol. In fact, in the Hadoop architecture, this principle is used when the DN is started on

#!/bin/bash#递归打印当前目录下的所有目录文件. PRINTF() {ls $| while ReadLine#一次读取每一行放到line变量中 Do[- D $/$line] && {dir="$/$line" Echo $DIR} dir1= ' DirName$DIR`#求路径. A= ' Ls-f$DIR 1| grep/| Grep"\$line\>"`#判断line是不是一个目录. if["$A"=="$line/"]; ThenPrintf"$

when using Find, just write the desired action in a file, you can use the exec to match the Find lookup, very convenient (In some operating systems only the-e x E C option is allowed to execute commands such as L s or ls-l). Most users use

Historical command HistoryOption:-C Empty History command-W Save History Command nowThe history command entered under Linux will be saved in the root directory: ~/root/.bash_history fileSave 1000 by default to modify environment variables in the/etc/

cat mail.sh#!/bin/bash#--------------------------------------------------# created:2015-05-04#  author:jimmygong# mail:[email protected]# function:shell mutt msmtp# version:1.0

######### #20150419 ############################# #题目: Variable a= ' a/b/c ' how to intercept get c @@@@@@@@@@@@@@@@ From the operation and maintenance class 21 long wing finishing @@@@@@@@@@@@@@@@@@@[[email protected] shell]$ uname -r 2.6.32-504.

The company's new demand, suspected PV and IP ratio is not right, see if there is malicious east:Nginx Configuration:Log_format main "" $http _user_agent "" $http _x_cookie "" $request _time "" $upstream

You can use, let (()) [] perform basic arithmetic operations, and use advanced operations bc more efficiently.Look directly at the code and the output is clear.Let[Zhengweiwu A: -~]$ no1=4[Zhengweiwu A: -~]$ no2=5[Zhengweiwu A: -~]$ Letresult=no1+no2

Suppose we define a variable as:File=/dir1/dir2/dir3/my.file.txtWe can replace each other with ${} to get different values:${file#*/}: Take out the first/its left string: dir1/dir2/dir3/my.file.txt${file##*/}: Take out the last/and left string:

Presumably the requirement is that the AIX system Usysfault command takes the fault light information, but this command appears to be performed only by the root user, and the other user executes the error. All sorts of ways to empower all fail, so

Suppose we define a variable as:File=/dir1/dir2/dir3/my.file.txtWe can use${ }Replace each to get different values:${file#*/}: Take out the first one./And the string to its left:Dir1/dir2/dir3/my.file.txt${file##*/}: Take the last one off./And the

Read the CU forum Shell 13 After a few small experiments, prepare to forget!Shell 13 Q Address: http://bbs.chinaunix.net/thread-218853-1-1.html#!/bin/bashfunction func_com () {Local a=1 local b= "2c3" Echo ${a}b echo $ab}function Func_arra Y ()

Tag: The grep command of the Shell scripting toolgrep (abbreviated from globally search a Regular expression and Print) is a powerful text-search tool for Linux systems that can search for text using regular expressions , and print out the matching

The coffee is too much to drink. I guess I'll have no sleep tonight. Mom, Egg.The arithmetic operation of the shell. There are too many. There are many tools available to download on the Web. This article only selects the commonly used to carry on

Summary of Shell Small issuesThis article source: http://blog.csdn.net/bluishglc/article/details/44276607 prohibited any form of reprint, or will entrust CSDN official maintenance rights! Summary of Shell Small issues If

$ -----The name of the current program is actually an internal parameter, unlike $1,$2 .... because it must have! $#----The total number of arguments passed to the program, that is, the legend of the array size$?----the previous code or shell

If your Zabbix Admin password is too weak or use the default password (Admin/zabbix), and the hacker cracked the password, Zabbix server in front of the hacker has no resistance. Hackers can create "system.run[command,]" Monitoring items to execute

1. View Current user (number of users) [email protected]: ~# who [| wc-l][email protected]: ~# whoKallen Tty4 2015-01-16 10:46Kallen tty5 2015-01-16 10:47Kallen Tty2 2015-01-16 10:42Kallen tty3 2015-01-16 10:42Root Tty6 2015-01-16 10:58Kallen tty1 2