Shell Scripting while loop

Education is not limited to just classrooms. It can be gained anytime, anywhere... - Ravi Ranjan (M.Tech-NIT)

Shell Scripting while loop

Linux scripting while loop is similar to C language while loop. There is a condition in while. And commands are executed till the condition is valid. Once condition becomes false, loop terminates.


Syntax of while loop is shown in the snapshot below,

Linux Shell Scripting While loop 1


We have shown the example of printing number in reverse order.

Shell Scripting While loop 2

Output is displayed in the below snapshot,

Shell Scripting While loop 3

while infinite loop:

Infinite loop is also called endless loop. It is made with while true (it means condition will always be true) or while : (it means an empty expression), where colon (:) is equivalent to no operation.

Shell Scripting While loop 4

Look at the above snapshot, this script includes while truesyntax.

Linux Shell Scripting While loop 5

Look at the above snapshot, this script includes while: syntax.

Both of them display the same output.