Next generation Unix pipe by Alex Larsson
That is a terrible idea: sometimes the app can take advantage of a constraint to minimize work done.In your example, if we just wanted to filter for a particular user, dps would have to print out ALL of the information and then you could pick at it.  This doesn't seem bad for ps (because there's a hard limit) but in many other examples the output could be much larger than what is needed.  That's why having filtering and output flags in many cases is more efficient in generating everything.As a side note: To demonstrate a dramatic example, I tried timing two things:    - dumping NASDAQ feed data for an entire day, pretty-printing, and then using fgrep
    - having the dumper do the search explicitly (new flags added to program)

Both outputs were sent to /dev/null.   The first ran in 35 minutes, the second in less than 1 minute