Shell

Guide At the beginning of learning Inux shell scripting, for its arithmetic and logical operations. It is estimated that many friends feel more difficult to accept. When using the special variable logical operator "[]", you must ensure that

#!/bin/bash tput civis while [ 1 ] do    tput clear    tput cup 3 10    tput setb 0    tput setf 2    echo -e "\e[1;32m$(date "+%Y-%m-%d %H:%M:%S  %A")\e[0m"    sleep 1 done Running in Xshell will have splash screen,

When you use the HBase shell for a Get or scan operation, you will occasionally see some values being converted into 16, just like the followingvalue=w\x5c5\x80So what exactly does this value equal? The algorithm is found after reviewing the data as

Single-branch if statement: If condition test actionThenCommand SequenceFi Example: Determine if the mount point directory exists, or create a new directory if it does not exist. [email protected] script]# cat chkmountdir.sh#!

Assigning values to variablesDefining an integer class using Declare-i[[email protected] scripts]# Aa=5+6[[email protected] scripts]# echo $aa 5+6[[email protected] scripts]# declare-i Aa[[ema Il protected] scripts]# aa=5+6[[email protected] scripts]

NMap, also known as Network Mapper, is the Web scanning and sniffing Toolkit under Linux, which has three basic functions, one is to detect whether a group of hosts are online, the second is to scan host ports, to sniff out network services, and to

(a) Conditions to determine if the meaning of-Z to-D[-A file] is true if file exists.[-B file] True if file exists and is a block special file.[-C file] True if file exists and is a special file of a word .　　[-D file] True if file exists and is a

This article is part of the Linux Shell Series Tutorial (10), more Linux shell tutorials: Linux Shell Tutorials Basically any language has its own looping statements, of course, the shell is no exception, today we introduce the use of shell for

Http://man.linuxde.net/testHttp://blog.chinaunix.net/uid-24780853-id-2578709.html[email protected] ~]# man testtest (1) User Commands Test (1) NAME test - Check file types and compare Valuessynopsis Test EXPRESSION t EST [EXPRESSION] []

Original address: http://www.cuiweiyou.com/1405.html0.shell[Email protected]:~# Hadoop Fsusage:hadoop fs [generic options] [-appendtofile ... ] [-cat [-IGNORECRC] ...] [-checksum ...] [-CHGRP [-R] GROUP PATH ...] [-chmod [-R] PATH ...] [-chown

The shell is a scripting language, so you have to have an interpreter to execute the scripts.The common shell scripting interpreters on Unix/linux include bash, sh, csh, Ksh, and so on, which are used to call them a shell. we often say that there

Shuffle question: Wash a pair of poker, what good way? Can be washed evenly, and can wash fast? How efficient is the order of chaos relative to a file?Chinaunix is really a place where the Shell masters are gathered, so long as you want to get the

Direct run will show time[Email protected] shell]# Datesat APR 12:56:47 CST 2016View Calendar[[email protected] shell]# cal April 2016Su Mo Tu We Th Fr Sa 1 2 3 4 5 6 7 8 910 11 12 13 14 15 1617 18 19 20 21 22 2324 25 26 27 28 29 30View a full year[[

This article is part of the "write-A-shell" series, in which we first complete a shell-based implementation of the most basic functionality in the shells. In this article, I will describe the implementation of the idea, as well as the introduction

IntroductionOften need to deal with shell commands, but there has been no systematic learning, then it will take 1-2 months to learn the shell command system, then open the magical journey of the shell command. This chapter focuses on the print

Method One of the $ expr length "Find out the length of this string from the Linux Bash shell." 57 Method Two Str1=aaaaaaaaaecho ${#str1}Echo-n xxxxx |wc-cecho Xxxx|awk ' {print length ($)} 'echo "$str" |awk ' {print length ($)} 'awk ' {$a =length ($

#!/bin/shmkdir  /home/zhengyk/desktop/tmp   #创建临时文件夹, used to store the extracted files #mkdir  /home/ zhengyk/desktop/local   #创建临时文件夹, used to store filter results List_alldir () {   for file in $ 1/*doif [ -d  $file  ]; thenlist_alldir 

The file descriptor is an integer associated with the file input and output. It is used to track files that have already been opened. The most common file descriptors are stdin, stdout, stderr. We can even redirect the contents of a file description

This article is part (vi) of the Linux Shell Series tutorial, more on the Shell Tutorial: Linux Shell Series Tutorials The shell is very powerful in programming, its array function is also very perfect, today we introduce the use of the shell

1. IntroductionSometimes when we run Java programs on Linux, we need to invoke some shell commands and scripts. The Runtime.getruntime (). Exec () method provides us with this functionality, and Runtime.getruntime () provides us with the following