Necessary tools for automatic operation and maintenance shell script introduction

Shell Scripts are implementations Linux/Unix An essential tool for system management and automatic operation and maintenance , It is also the knowledge that every operation and maintenance engineer needs to master , It can help us improve our work efficiency , It can also reduce unnecessary repetitive work . But a lot of people are right shell Don't understand , I can't tell what is shell, What is? shell Script , Next, let's introduce... Through this article .

What is? shell?

Shell Refers to the command interpreter . Its function is to interpret and execute commands and programs entered by the user , Every command the user enters ,Shell Just explain and implement one of them . This dialogue mode that can get an immediate response as soon as you enter a command on the keyboard is called interactive mode .

What is? Shell Script ？

When a command or program statement is executed through a program file rather than a command line , Then this program is called Shell Script . If Shell The script has many built-in commands 、 Statement and loop control , Then execute it all at once , This way of executing scripts through files is called non interactive . Users can go to Shell Enter a series of commands and command statement combinations in the script . These orders 、 Variables and process control statements are organically combined , It forms a powerful Shell Script .

Shell Script in Linux Position in operation and maintenance work

Shell Scripting languages are well suited for dealing with plain text data , and Linux Almost all configuration files in the system 、 Log files ( Such as NFS、Rsync、Httpd、Nginx、LVS、MySQL etc. ), And most startup files are plain text files . therefore , Learn from good examples shell Scripting language , You can use it in Linux Play a huge role in the system .