deleting some empty lines with sed

[Larry Wall]

In article <281DB41B.9E6 at marob.uucp> daveh at marob.uucp (Dave Hammond) writes:
: Perhaps I'm oversimplifying the problem, but wouldn't
: 
: tr -s '\012'
: 
: squeeze multiple, consecutive newlines to a single newline?

Yes, it would, and yes, you are.  They wanted to squeeze 3 or more
consecutive newlines down to 2.

Incidentally, with perl 3.044 and later you can do it with

	perl -00pe 's/^\n+//'

or, less efficiently (because of file slurping overhead and string copying
due to modifying the middle of a long string, and because the previous
solution uses anchored search),

	perl -0777pe 's/\n{3,}/\n\n/g'

Oddly enough, any octal number will work in place of 0777 except 012, which
would set the input delimiter to newline.

Larry Wall
lwall at netlabs.com