Shell

The test command is very powerful, but it is difficult to satisfy its escape requirements and the difference between string and arithmetic comparisons. Greater than Less than Equals Not equal to If ["$a"-gt "$b"]

I. OverviewThe shell is a program written in C that provides access to the operating system kernel services through a shell user. It is similar to DOS command and later cmd.exe. The shell is both a command language and a programming language.Shell

When executing shell script, if judgment statement error#!/bin/bashif [0 = = $testNum]then echo "Check result:0" fi　　Testnum is not defined when used, no assignment is empty (originally defined, just a clerical error is similar to tsetnum), after

First, condition judgmentClassification:Condition test TypeNumerical testString testFile test1. Conditional test ExpressionsFormat:[Expression][[Expression]]Test expression2. Numerical test Parameters Description -eq

Logical judgments in shell scripts1.if then fi[[email protected] shell]# cat if1.sh#!/bin/basha=5if [ $a -gt 3 ]then echo okfi2.if then else fi:[email protected] shell]# sh -x if2.sh + a=1+ ‘[‘ 1 -gt 3 ‘]‘+ echo nooknook[[email protected]

在study(Shell)专栏中，会深刻学习到shell编程And as an OPS person, the most basic ability is to learn shell script programmingTo improve efficiency in our work!Shell Programming:Compiler: Also called interpreterThe shell provides us with another function: To

ADB Shell Monkey-P Com.android.recorder--throttle--ignore-crashes--monitor-native-crashes--ignore-security-exceptions--ignore-timeouts--ignore-native-crashes--pct-syskeys 10--pct-nav 20--pct-majornav 20--pct-touch 40--pct-appswitch 10-v-v-V 20000

1, guess the number: first let the system randomly generated a number, give this number to a range (the number of the first 50 and 50), let the user input guess the number, the input judgment, if not meet the number to give high and low hint,

Tilde expansion with wildcard characterstwo types of expansion in the shell that are related to file names . The first one is the wave number expansion . , The second type is a wildcard expansion .Wave Number expansion If the first character of the

If the expression contains special characters, the Shell will replace it. For example, using a variable in double quotes is a substitution, and an escape character is also a substitution.As an example: #!/bin/bash A=ten echo-

Operator Describe Example File comparison Operators -e filename True if filename exists [-e/var/log/syslog] -D filename True if filename is a directory [-d/tmp/mydir]

Before writing the IF condition to judge, generally in writing the shell script may use the dead loop at this time need while statement, it is the best way to do the dead loop, before the while loop need to tell the file test, because it is often

I know two methods: add the path (Nautilus |Pcmanfm dir_path) Method 1: Use Nautilus Install: sudo apt-Get intstall Nautilus Effect: Nautilus ~ Method 2: Use pcmanfm Installation: sudo apt-Get intstall pcmanfm Effect:Pcmanfm ~ However,

In shell, there are three types of quotation marks: single quotation marks, double quotation marks, and reverse quotation marks. Single quotation marks 'all characters enclosed by single quotation marks are common characters. When special characters

Document directory Task: display current bash prompt (PS1) Task: modify current bash prompt Task: add colors to the prompt Task: how to make the prompt setting permanent Tput command Handy tput commands Colors {code} code for tput command

Sudo addgroup hadoop # Add a hadoop GroupSudo usermod-a-g hadoop Larry # Add the current user to the hadoop GroupSudo gedit ETC/sudoers # Add the hadoop group to sudoerHadoop all = (all) All after root all = (all) All Modify hadoop Directory

Linux Command Line and shell script Programming This time, I read the Linux Command Line and shell script programming book for 3rd Times. In general, this book is quite good. It is suitable for beginners. I also learned about shell programming from

Author: gnuhpcSource: http://www.cnblogs.com/gnuhpc/ Offline backup/restore the TDS 1. Preparation (1) logon to the server as root.(2) open a terminal, check if there is the script named tarbackup. Sh in/usr/local/bin directory(3) make sure you

Differences between console, terminal, tty, shell, and other concepts Linux has been used for some time, but I still cannot understand the differences between these concepts. Although I have been using it all the time, many concepts are vague, so it

Shell-encrypted shc vulnerability and shell-encrypted shc Vulnerability Recently, I have been compiling Shell scripts for customers to use. I will inevitably encounter some sensitive information that I don't want them to know. So I used Shc script