Linux Bash Shell Basic syntax

The use and setting of a variable (note that there can be no spaces before and after the equals sign)

1. Read

Read the input from the keyboard assignment to the variable, using the following method

[Email protected]:/opt/android-sdk/sdk/# read Var_readthis is ' What I get ' from my Keyboard[email protected]:E Cho  ${var_read}this is that I get from my keyboard

2. Declare

Declare variables, if not add declare when defining variables, actually the same effect

[Email protected]:/opt/android-sdk/sdk/# declare a=hw[email protected]:/opt/android-sdk/sdk/# b=hw[ Email protected]:echo  ${a}hw[email protected]:echo  ${b}hw

Also, if the DECLARE command has another syntax:

-A sets the following variable to array

-I set the integer to the back of the change

-R Sets the following variable to read-only

3. Export

Change the following variable into an environment variable, which can be seen in all shells

[Email protected]:/opt/android-sdk/sdk/# var_1=hw[email protected]:/opt/android-sdk/sdk/# Export var_1 [Email protected]:/opt/android-sdk/sdk/# export VAR_2=HW

4. Array

How to define an array: var[index]=content

Linux Bash Shell Basic syntax