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bashloopsdo-while

Emulating a do-while loop in Bash

What is the best way to emulate a do-while loop in Bash?

I could check for the condition before entering the while loop, and then continue re-checking the condition in the loop, but that's duplicated code. Is there a cleaner way?

Pseudo code of my script:

while [ current_time <= $cutoff ]; do
    check_if_file_present
    #do other stuff
done

This doesn't perform check_if_file_present if launched after the $cutoff time, and a do-while would.

Solution

  • Two simple solutions:

    1. Execute your code once before the while loop

      actions() {
   check_if_file_present
   # Do other stuff
}

actions #1st execution
while [ current_time <= $cutoff ]; do
   actions # Loop execution
done

    2. Or:

      while : ; do
    actions
    [[ current_time <= $cutoff ]] || break
done