Basic concepts of Linux shell programming

Shell programming is actually a program that combines multiple commands, based on bash.

Serious attention

The difference between $hostname and $ (hostname)

$hostname is to take the value of the hostname variable

$ (hostname) is the execution result of the fetch hostname command

Shell's basic format

First line: #!/bin/bash description command interpreter

Second line: function description

You can write a formal script in the back.

Write code comments after each complex code, and if there is a hierarchical relationship it is best to indent and add a blank line moderately

Basic concepts of Linux shell programming