Obviously for many cases avoiding output is better than post-output filtering. For these cases the originating process should do the filtering. However, in many

Obviously for many cases avoiding output is better than post-output filtering. For these cases the originating process should do the filtering. However, in many practical situations the data sets are small enough to not matter, or the operation wanted will not filter out most data anyway. Basically, you're arguing that grep is a bad tool (it has the same issues) yet its a very commonly used tool.