There are any number of tools for resizing the browser window to check responsive designs. One that stands out for me is the Media Query Bookmarklet from the Sparkbox Foundry. This shows you the currently applied media queries and browser size in both pixels and ems.
Once you've used this you'll wonder how you managed without it.
Note: The main page says in works in Chrome and Safari. It also works in IE10.
Details at http://seesparkbox.com/foundry/media_query_bookmarklet
Full Scale made the Inc. 5000 for the fifth year straight, the 12th listing across my three companies. Here is why the one award you cannot buy is worth stopping for.
I let a tool I liked sit dead for a year rather than build the features I wanted. An MCP server meant I never had to, and your customers can do the same to your product.
du -sh for the quick answer, ncdu for the cleanup, df for the disk itself: every command for checking directory size in Linux, plus why du and df never agree.
One :%s command replaces every match in a file before a find dialog would even open. The Vim substitute patterns worth the muscle memory: flags, ranges, capture groups, and multi-file edits.