envsubst vs bash here-doc

envsubst_vs_heredoc.sh

#
# With envsubst
#
$ cat webadmin.ini.tpl # a template file is required
[User:${CUBERITE_USERNAME}]
Password=${CUBERITE_PASSWORD}

[WebAdmin]
Enabled=1
Ports=8080
$ export CUBERITE_USERNAME=admin #vars need to be exported
$ export CUBERITE_PASSWORD=cuberite
$ envsubst < webadmin.ini.tpl > webadmin.ini # neat and tidy single liner
$ cat webadmin.ini # result
[User:admin]
Password=cuberite

[WebAdmin]
Enabled=1
Ports=8080
#
# with bash here-doc
#
$ CUBERITE_USERNAME=admin # vars need not to be exported
$ CUBERITE_PASSWORD=cuberite
$ cat <<EOF > webadmini.ini # crowded but no other file required
[User:${CUBERITE_USERNAME}]
Password=${CUBERITE_PASSWORD}

[WebAdmin]
Enabled=1
Ports=8080
EOF
$ cat webadmin.ini # result
[User:admin]
Password=cuberite

[WebAdmin]
Enabled=1
Ports=8080