Replace delimited block of text in file with the contents of another file

Question

I need to write a simple script to replace a block of text in a configuration file with the contents of another file.

Let\'s assume with have the following simplifie

Answer 1

You may also use the ed command (cf. http://wiki.bash-hackers.org/howto/edit-ed ):

cat <<-'EOF' | sed -e 's/^ *//' -e 's/ *$//' | ed -s server.xml
   H
   /BEGIN realm/i
   .
   /BEGIN realm/+1,/END realm/-1d
   .-1r realm.xml
   wq
EOF