sed script to combine blank lines?

[Maarten Litmaath]

In article <192 at vlsi.ll.mit.edu> young at vlsi.ll.mit.edu (George Young) writes:
\Is there a 'sed' wizard out there?  I often want to take a big ascii file
\(like a .c file after cc -E) and collapse each group of 'blank' lines
\into exactly one blank line.  'Blank' here is any combination of blanks,
\tabs and maybe ^L's.

How about `awk'?

% cat /usr/local/bin/deblank
#! /bin/sh
exec awk '$0 !~ /^[ \t\f]*$/ { print; prev = 0; next }
		{ if (prev) next }
		{ prev = 1; print "" }
'
%
-- 
Hippic sport:                         |Maarten Litmaath @ Free U Amsterdam:
             a contradiction in terms.|maart at cs.vu.nl, mcvax!botter!maart