10.1 Commond: Suppress normal shell function lookups
10.2 exec: Replacing the current shell process with the Execute command
10.3 Bash:gnu's Bourne-again shell interpreter
10.4 Builtin: Execute shell built-in command
10.5 Enable:
Chapter 1th whileLooping Statementsin a programming language , a while loop is a statement of a control flow that uses an expression that returns a Boolean value that, when the return value of the expression is true , repeats the condition of the
The VI editor has three status modes "VI file name (or path + file name)"1. Command mode2. Input mode3. Last-line modeConversion between three modesVi. start and exit of the VI editorGo directly to the editing environment$ VIEnter the editing
One, the shell quotes1. "", double quotation marks (do not retain the full content, such as encountered $, anti-quotes, \ etc will execute the corresponding shell)echo "Today is `date`" -> Today is Wed Aug 2. Single quotation mark (full retention
Linux Shell location Variables in detail what are positional variables?
Simply put, when the user runs the script, input parameters, the variables corresponding to these parameters are called positional variables.
Logical operations in shell programming, with or without, short-circuit operations, XOR operations, we use the simplest way to understand the XOR.XOR: ^XOR two values, same as false, different for trueUnderstandably, two values refer to binary
DirectoryI. Condition selection: If statementTwo. Conditional judgment: Case statementThree. For loopI. Condition selection: If statement
Single Branchif judgment condition; thenBranch code with true conditionFiExample: Judging whether a number
Before using shell to write scripts, sometimes not only to define a configuration file, often have a template, different environments directly replace the same template content to use, however, until then, has been used in the SED, awk, grep and so
1.1 The following table is a logical operatorTips:! Inverse: A logical value that is opposite to a logical value.-A Chinese meaning is with (&&): Two logical values are true return values are true, and vice versa is false.-O Chinese meaning yes or
Transferred from: http://blog.csdn.net/huanbia/article/details/51318278Problem description
When using SECURECRT to open Spark-shell, sometimes the following problems, when the wrong time to press the BACKSPACE (BACKSPACE) or delete (delete key),
Backs up all modified files in the current directory within the last 24 hours in a "tarball" (Files that have been processed by tar and gzip).The program code is as follows:#!/bin/bashBACKUPFILE=backup-$(date +%y-%m-%d)#
1.bash supports one-dimensional arrays (multidimensional arrays are not supported) and does not qualify the size of the array(1) define an array:Array_name= (value0 value1 value2 value3)OrArray_name= (Value0Value1value2Value3)or individually defined:
Multiple values can be stored in an arrayThe shell array is represented by parentheses, and the elements are separated by a "space" symbol.Syntax format:Array_name= (value1 value2 ... valuen)Defining
Power ShellNote: The following content is written on a non-Windows platform, there may be spelling errors, if any, please correct me, I will amend as soon as possible. It can be implemented using the PowerShell configuration file (\ Profile). \)The
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