bash programming book

2 3 Calculate how much from 1 to N, n is the parameter you bring in when you execute the script? VI for3.sh#!/bin/bashfor for I in ' seq $ ' do let sum+= $idoneecho "sum= $sum" execution: #bash for3.sh 100sum=5050 5 Seconds Countdown Daojishi.sh#!/bin/bashn=5for i in ' seq 5 ' do echo ' countdown: $n ' Let n--sleep 1done execution: #bash daojishi.sh countdown: 5 Countdown: 4 Cou

#version:0.0.15#author:lcc.org#description:nbsp, ..... Dir= "/mnt/sysroot" [-d $DIR ]| | install-d $DIRfunction cpcmd{cmd_path=$ (which--skip-alias$1) Local cmdir=$ (echo $cmd _path|sed ' s,/$,, ' |sed-r ' [email Protected] (. */) ([^/]+) @\[emailprotected] ') [-d $DIR $cmdir]| | install-d $DIR $cmdir[-f $DIR $cmd_path]echo-e "\033[32m$dir$cmd_path\033[0misexist" | | cp $cmd _path $DIR $cmd_path}functioncp_lib{foriin$ ( ldd $cmd _path|grep-o--color=auto "/.*[[:space:]" |tr-d ' '); dolocallibd

As a result of the work, several bash scripts were written in the previous months, primarily for automated testing, packaging, installation packages, and so on. Although compared to C + + programming, to be simple, stupid, but it in the Unix-like system can greatly improve the efficiency of the work. So here's a brief summary of some of the considerations in scripting. 1. Shell Overview The shell is an inte

A detailed description of the variables of Bash programming under Linux (i)1. Language classification:1.1. Static language: Compiled languageStrongly typed: Variables must be declared beforehand and even initialized before they are used;Programs written in advance into executable formatRepresentatives are: C, C + +, JAVA, C #Dynamic language: Interpreted languageWeak type: variable time declaration, even th

Labels: Bash basics and standard I/O pipeline shell programming Basics 1. Bash basics and configurations From the user's perspective, the shell type: Logon Shell Log On Through a terminal normally Su-Username Su-l Username Non-Logon Shell Su Username Virtual terminal opened under the graphic Terminal Automatically executed shell script

Bash Script Programming:If statement, Bash-n, Bash-xCONDITION:Bash command:The execution status result of the command;Success: TrueFailure: flaseThe meaning of success or failure: Depending on the command used;Single branch:if CONDITION; ThenIf-trueFiDual Branch:if CONDITION; ThenIf-trueElseIf-falseFiMulti-branch:if CONDITION1; ThenIf-trueElif CONDITION2; ThenIf-

;Environment variables:Variable assignment:(1) Export Name=value(2) Name=valueExport name(3) Declare-x Name=value(4) Name=valueDeclare-x NameVariable reference: ${name}, $nameNote: Bash has many environment variables embedded in it (usually all uppercase characters) to define the work environment for bashPATH, Histfile, Histsize, Histfilesize, Histcontrol, SHELL, HOME, UID, PWD, oldpwdView environment variables: Export, Declare-x, PRINTENV, envUndo en

'] ' + echo CCCompare the next 5-6 lines can be found, the difference is to judge once, or judge two times4.2 String Judgments#!/bin/bash-xstr1= "ABC" If [-Z "$str 1"]; Then Echo ' str1 was empty ' else echo ' str1 is not empty ' fiprintf "\ n" str2= "" if [-N "$str 2"]; then Echo ' str2 I s not empty ' else echo ' str2 is empty ' fiprintf ' \ n ' If ["$str 1" = "$str 2"]; then echo ' str1 = str2 ' Else Echo ' str1 Note:-N is-not empty to deter

Location and special variables for bash programming under Linux (iv)1.bash Position Variable:$, $, ... The 1th parameter, the second argument, ...Shift poll substitution, cullingExample: Using a script to interpret the meaning of positional variables, create the following script:Nano shift.sh Create a script file and add the following:#!/bin/

Can I do about It?Matters ComputationalType Theory and functional programmingGetting started with Open source development (PDF)Database Fundamentals (PDF)Clever algorithmsSummary of the GoF Design PatternsFlow based programmingAlgorithms and Data-structures (PDF)Compiler Construction (PDF)Project Oberon (PDF)The Little Book of semaphoresEssential Skills for Agile developmentI Am a BugMining of Massive DatasetsData-intensive Text processing with MapRe

Linux under Bash programming character test with For Loop statement (v)1. Character test:= =: Test for equality, equality is true, not equal to False! =: Test Whether it is unequal, not equal to true, etc as false>,-N String: Tests whether the specified string is empty, empty is true, or false-Z String: Tests whether the specified string is not empty, is not empty, and the null is False2.for loop: Enter con

BASH Programming Conditional judgment: Determine whether the prerequisites for subsequent operations are satisfiedCommon Types of Judgments:Integer judgment:Character Judgment:File judgment:$?: Status return value0: True1-255: FakeWe can use the status return value as the judging condition, do not need to add ' 'Boolean value:True and FalseLogical operation:and Operation:Or Operation: | |Non-op:!The conditi

Bash Programming Essentialsvariables :Local variable: Valid only for the current shell process, not valid for other shells other than the current shell (including its parent, child, etc.);Environment variables: Valid for Shell processes and their child shell processes;Local variables: Valid only within a certain piece of code space in the current shell process, usually for function local programs;Positional

Linux under Bash programming combination test and write comprehensive script (v)1.Bash Programming Combination test conditions-A: With relation-O: or relationship!: Non-relationalPresentation Method 1:[$#-gt 100-a $#-le 500]Presentation method 2:[$#-gt] [$#-le 500]2. Write a script that adds and deletes users as follo

File test operations-advanced bash Script Programming Guide /Span> 7.2 file testing operations----------------Returns true if...-E file exists-File a exists.This option has the same effect as-e, but it has been discarded and is not encouraged.-F file is a regular file (not a directory or a device file)-S file length is not 0-D files are directories.-File B is a block device (floppy disk, cdrom, etc)-The c f

Bash script programming Step-by-step articlefunction, array, string manipulationfunction: functions in scripting are fundamentally different from the functions in our math. The functions here are mainly for the purpose of implementing procedural programming code reuse. For example, a function to calculate a number, when we need to use the calculation of numbers,

Programming styleProgram programming to solve problemsThe instruction organizes the data, the instruction is stackedTo complete a complex taskSequential execution: Traversing execution, running one by oneSelect execution: There is a selection criteria, the result can only have one choice, only to execute some code fragmentsLoop execution: Run the same operation on a class of objects one by one, similar to t

In bash programming, it often involves using while statements to deal with the number of unknown loops at times. While syntax While [Express]do#commanddone2. Practical Practice Prompt to enter an integer greater than 10 less than 20; While1.sh:#!/bin/bashecho-n "Please input a digit between:" Read Nwhile [$n-lt 10]| | [$n-gt]doecho-n "Please input a digit between an

~/tscripts $ unset namereadonly6. Non-read-only variable can be canceled, cancel print to empty[Email protected] ~/tscripts $ unname=~/~/tscripts $ echo $unname7. Single quotation marks~ $ name='Leo'$name ' $'name'8. Double quotes" I am $name " "\\i am $name \ \"\i am Leo \9. Stitching strings" He is $name " is "$name is handsome"! is handsome! "$name is handsome! "-bash:! " : Event not found10. Get the string length[Email protected] ~ $ echo ${