Shell conditions and loops

A If statement

if [expression]

Then

Elif[expression]

Then

Else

Fi

Note: There should be a space before and after expression;

Then you can start another line, or you can go with the if peers, to add '; ' ；

Two Case mode

Case Value in

Mode 1)

Command1

Command2

Command3

;;

Mode 2)

Command1

Command2

Command3

;;

*)

Command1

Command2

Command3

;;

Esac

Cases:

Case $value in

value1)

Command

;;

value2)

Command

;;

Esac

Three For loop

For variable in list

Do

Command1

Command2

...

CommandN

Done

Four While loop

While [command]

Do

Statement (s) to BES executed if command is true

Done

Five Util cycle

Until command

Do

Statement (s) to being executed until command is true

Done

Shell conditions and loops