Shell

Error One:The alias of the field cannot be used after Hive's where,Error Two:You cannot define a function in Hive's groupby, otherwise an error (replaced with a nested select)Error Three:When running: $./hive_game_operationstatis5.sh, the error

Rookie learn shell script, hands practiced hand simple small experiment, use shell script to determine if Nginx is normal operation, if not run the Nginx service start up.First, based on process judgment1, get the nginx process to determine whether

A simple shell script A simple shell script to writeSuppose I want to know how many people are currently logged on the system, and use the who command to tell you who is logged in to the system now:1.[[email protected] ~]$ who2.KANO

the role of the shell is to convert a user-entered text command into an internal nuclear identification data instruction to the kernel for execution, and the kernel needs to be translated into binary to be executed by the CPU bottomthe user

Awk is a powerful text analysis tool, with the search for grep and the editing of SED, which is especially powerful when it comes to analyzing data and generating reports. To put it simply, awk reads the file line-by-row, using spaces as the default

Debugging a serial port under Linux is a hassle, especially in an embedded environment, and many times it is time to debug with another device.Here to figure out a feasible serial debugging method, you can simply check whether the serial port is

The Find command, which is used as often as a CD. It is only possible that the majority of the time it takes only one or two parameters to be used. Or, barely enough. But when we take the initiative to look at the manual of Find, we will find that

Shell Features:History is saved in ~/.bash_hostory and retains 1000 records: defined inEcho $HISTSIZE!: Previous Command!$: Last parameter of previous command! 950: No. 950 order!c: The most recent command in history that starts with CTAB: Command

First, mathematical operations 1. Expr commandThis command can perform mathematical operations on the command line.650) this.width=650; "title=" 1451372345836139.jpg "alt=" 8.jpg "src=" http://www.178linux.com/ueditor/php/upload/ Image/20151229/1451

Traverse directory where all files are directories or files for file in. /* do if test-f $file then echo $file is the file fi if test-d $file then echo $file is the directory FidoneFilelist= 'ls./Proto 'Echo$filelist

Monitoring ideas, Architecture introductionRequirements: Use the shell to customize a variety of personalized alarm tools, but the need for unified management, standardized management.Idea: Specify a script package that contains the main program,

Quote: I have not written a shell script before, perhaps because of laziness, perhaps not forced to write to the point of the shell. However, some time ago, the job requirements, required to rerun a few months of the script, these scripts are timed

1. File permissions1.1 The user has a special permission called Setuid (S), which appears in the execution permission (x) location, and the Setuid permission allows the user to execute the executable file with the owner's permission, even if the

Application of eval in shellEval can be used for nesting of variablesDr=ddir$inumEval ssdir=$ (Echo \$ $SR)Example:#!/bin/bashDate= ' Date +%y%m%d

Transferred from: http://blog.chinaunix.net/uid-23046336-id-3475462.htmlPrograms programmed under Linux apes know shell scripts, and even if you're not familiar with them, you should have heard them! What about the dead loop in the shell script?For

Detects whether the IP entered is legitimate#!/bin/bashRead-p "Input An IP address:" Ip_addrN1= ' echo $ip _addr|awk-f. ' {print $} 'N2= ' echo $ip _addr|awk-f. ' {print $} 'N3= ' echo $ip _addr|awk-f. ' {print $} 'N4= ' echo $ip _addr|awk-f. '

Shell redirection Debugging informationFulinux*************************************************************************************************************** ***********************Author: fulinuxReprint statement:

DescriptionMultiple tomcat containers, while starting and shutting down, use pipework control for each Docker container's network management. This script is used to manage the creation, deletion, startup, and shutdown of multiple containers. The

The first thing to think about is if else conditional judgment statement, the following gives a comprehensive statement: ifcondition Thencondition istrueExecute all commandselifStatementelifCondition1 ThenCondition1 istrueExecute all

First, function: function1.function Conceptfunction is a Process-programmed , the purpose is to Code Reuse , is a Modular Programming , Structured Programming Programming Method function: The code of an independent function as a whole, and a name