How to list variables declared in script in bash?

Question

In my script in bash, there are lot of variables, and I have to make something to save them to file. My question is how to list all variables declared in my script and get list like this:

VARIABLE1=abc
VARIABLE2=def
VARIABLE3=ghi

Answer 1

set will output the variables, unfortunately it will also output the functions defines as well.

Luckily POSIX mode only outputs the variables:

( set -o posix ; set ) | less

Piping to less, or redirect to where you want the options.

So to get the variables declared in just the script:

( set -o posix ; set ) >/tmp/variables.before
source script
( set -o posix ; set ) >/tmp/variables.after
diff /tmp/variables.before /tmp/variables.after
rm /tmp/variables.before /tmp/variables.after

(Or at least something based on that :-) )