How to paste many lines to a file using a bash script?

Question

I'm writing a script which will automatically configure a NIS client with the correct settings. I'm trying to set the /etc/nsswitch.conf file and I'd like to overwrite whatever is already there with my settings. Now my question is, how can I do that? how can i paste about 20 lines of settings into the client's nsswitch.conf file straight from the script? I know i can do something like:

echo "line 1" > /etc/nsswitch.conf
echo "line 2" >> /etc/nsswitch.conf

But that's an ugly way to do it, I hope there is a better way to achieve this goal

Answer 1

I would use cat together with here-doc syntax for this:

cat <<EOF > /etc/nsswitch.conf
group:          compat
shadow:         compat

hosts:          files mdns4_minimal [NOTFOUND=return] dns mdns4
...
EOF

The statement above will overwrite or create the file with the contents between the first line and EOF. In the form above even variables like group: $group would be expanded by bash. If you don't want this, then use <<'EOF' (note the single quotes ' around the EOF)