How to prevent "smart searching" in Safari?
Proper way out:


open the search engine page (e.g.:google.com) and paste the string into the search field.


Easiest way out:


paste the above into the URL bar (which is increasingly abused as a search field as well.) 

To indicate that you are cleverer than Safari, jump to the first position and insert a space character. (e.g. Ctrl+a, followed by Space)

That indicates to the browser that you are searching for a string and not trying to insert a botched URL. The leading space will be ignored by your search engine. This works in almost all cases when you want to make sure that Safari parses the contents of the URL bar not as an address but as a search string.

Now some strings seem to be more equal than others. Input "/etc/inetd.conf" and indeed Safari also ignores the first space for that. Then there are other examples like:
 /private/etc searches directly, /private searches directly, /private/ opens a Finder window… Some paths seem to be hardcoded.

In the example above / etc/inetd.conf should take you to a desired result.