I think we want to use `&> /dev/null` for redirection as it ensures absolute silence:

```
grep "chef_server_webui\[[\'\"]enable[\'\"]\]" /etc/chef-server/chef-server.rb &> /dev/null
```

The existing way complains if the file being grepped does not exist:

```
# grep "chef_server_webui\[[\'\"]enable[\'\"]\]" /etc/chef-server/chef-server.rb 2>&1 >/dev/null
grep: /etc/chef-server/chef-server.rb: No such file or directory
```