How to remove extra spaces in bash?

Question

How to remove extra spaces in variable HEAD?

HEAD=\"    how to  remove    extra        spaces                     \"

Result:

Answer 1

I would make use of tr to remove the extra spaces, and xargs to trim the back and front.

TEXT="     This          is  some                             text   "
echo $(echo $TEXT | tr -s " " | xargs)

# [...]$ This is some text