Syntax for a single-line Bash infinite while loop

Question

I am having trouble coming up with the right combination of semicolons and/or braces. I\'d like to do this, but as a one-liner from the command line:

while [         


        

Answer 1

If I can give two practical examples (with a bit of "emotion").

This writes the name of all files ended with ".jpg" in the folder "img":

for f in *; do if [ "${f#*.}" == 'jpg' ]; then echo $f; fi; done

This deletes them:

for f in *; do if [ "${f#*.}" == 'jpg' ]; then rm -r $f; fi; done

Just trying to contribute.