best bash scripting book

#description:galaxycd/varfori in$ (Ls/var);doif[-f $i ];then echo "Commonfile." elif[-L $i ];thenecho "Symbolicfile ." elif[-d $i ];thenecho "DirectOry. " elseecho "Othertype" fidone method three:#!/bin/bash# version:0.0.8#author:lcc.org#description:adddirforiin$ ( Ls/var) doif[-f/var/$i ];thenecho "Commonfile" elif[ -l/var/$i ];thenecho "Symbolicfile" elif[-d/var/$i ]; thenecho "Directory" elseecho "Othertype" FidoneExample four: How many listen are

Bash (GNU Bourne-again Shell) is a Unix shell written for the GNU program, which is the default shell used by many Linux platforms.Variables for bash scripting:1. $BASHRepresents the path of a bash binary program fileEg: Edit the bash file, such as 1.sh, in which the followi

used with variable names, and if the loop body does not include a variable name, a dead loop may occurHow the list is generated:1) Give a direct2) List of pure integersSEQ: Output An integer listseq [First [INCREMENT]] Last3) curly braces unfold{first.. Last}4) return value of the execution result of the command5) GLOBBING6) references to certain variables: [email protected], $*Features of the For loop:1. There is almost no cycle of death;2. The entire list needs to be loaded into memory during

Bash shell scripting Getting Started (iii) cycleWhat is loop execution?To run a code segment repeatedly multiple timesHow many times to run repeatedly:Number of cycles known beforehandNumber of cycles unknown beforehandThere are entry conditions and exit conditionsRelated commands: For, while, Until,selet,Use for commandRole:Assigns the element in the list to the "variable name" in turn; The loop body is ex

addition to Shebang, the # occupies the absolute beginning of the content, is the comment line, the interpreter ignores the contents of such a line;3. The explanation ignores all blank lines in the script;4. Lots of commands and keywords (if,else,then,do,while,for, ... ）Note: Once the shell script runs in the current shell according to Shebang's instructions, an interpreter (child shell) is opened explaining the execution of the code, and the contents of the shell script are implemented in a ch

; Thenuserdel-r $USER [$DEBUG-eq 1] ECho "Delete $USER finished." else[$DEBUG-eq 1] echo "$USER not exist." Fidonefi Exercise: Write a script showlogged.sh, which uses the format: Showlogged.sh-v-c-h|--help where the-h option can only be used alone to display help information; the-C option displays the number of users logged on on the current system If you use the-V option at the same time, both the number of simultaneous users logged in and the information about the logged-on user are display

/wyfs02/m02/7f/11/wkiom1cr12dwqsklaadjvt32yyi610.jpg " title=" help.jpg " alt=" Wkiom1cr12dwqsklaadjvt32yyi610.jpg " >. admuseradv abcdefg & nbsp options or incorrect parameter errors result in error messages 650) this.width=650; "src=" Http://s5.51cto.com/wyfs02/M02/7F/11/wKiom1cR16iQ3Av7AACRq6FruD0836.jpg "title=" Error.jpg "alt=" Wkiom1cr16iq3av7aacrq6frud0836.jpg "/>This article is from the "Xavier Willow" blog, please be sure to keep this source http://willow.blog.51cto.com/6574604/176440

True when the length of a string is greater than 0 -Z str1 True when the length of a string is 0 Str True when the string is non-empty As an example, compare strings to test the user id:If ["$ (whoami)"! = ' root ']; Thenecho "You had no permission to run $ as Non-root user."Exit 1;Fi Numeric comparison (integer) operator Compare Results Num1-eq num2 Two numbers equal to True

Learn more about the character test of Linux and the practice of bash scriptingOne, character test options= =: Tests whether two strings are equal, equals true, and not equal to false.！ =: Tests whether two strings are unequal, unequal to true, and equal to false.-N String: Tests whether the specified string is empty, NULL is true, and is not NULL for false.-Z String: Tests whether the specified string is not empty, is not empty, is true, and Null is