excluding first and last lines from sed /START/,/END/

Question

Consider the input:

=sec1=
some-line
some-other-line

foo
bar=baz

=sec2=
c=baz

If I wish to process only =sec1= I can for example comment

Answer 1

you could also use awk

awk '/sec1/{f=1;print;next}f && !/sec2/{ $0="#"$0}/sec2/{f=0}1' file