Shell script if statement

The structure of the if statement

Single branch structure

A corresponding fi must be connected at the end of the if statement to represent the end of the statement.

The judgment process of if single branch structure.

if conditional test operation

then command sequence

fi #Ending statement

if a=yes

ze output okok

Dual-branch structure

Judgment process of if double-branch structure

if conditional test operation

then command sequence 1

else command sequence 2

fi #Ending statement

Run it

Multi-branch structure

if conditional test operation 1

then command sequence 1

elif conditional test operation 2

then command sequence 2

else

Command sequence 3

fi