configwriter.sh

#!/usr/bin/env bash

tr=trigger
tr='==============_AUTOGENERATED_-_EDITS_BELOW_WILL_BE_CLOBBERED'

[ ! -f test ] && cat <<EOF >test
this
is a
trigger
test
some config is
probably here
EOF

day=$(date +%A)
cat <<EOF >data
this is
$day's data.
EOF

cat \
    <(awk "/$tr/{exit}{print}" test) \
    <(echo "$tr") \
    <(date) \
    <(uname -a) \
    data \
    > output

cat output

mv output test

# make external changes to ./test