#!/bin/sh

set | sed -n '
:x

# if no occurrence of ‘=()’ print and load next line
/=()/! { p; b; }
/ () $/! { p; b; }

# possible start of functions section
# save the line in case this is a var like FOO="() "
h

# if the next line has a brace, we quit because
# nothing comes after functions
n
/^{/ q

# print the old line
x; p

# work on the new line now
x; bx
'