sed Guru wanted

[Robert Bonomi]

> From owner-freebsd-questions at freebsd.org  Fri Jul 12 05:13:11 2013
> Date: Fri, 12 Jul 2013 11:04:04 +0200
> From: Matthias Apitz <guru at unixarea.de>
> To: freebsd-questions at freebsd.org
> Subject: sed Guru wanted
>
>
> Hello,
>
> I can delete in a text file with
>
>  sed '/pattern1/,/pattern2/d' < file
>
> all lines between the lines with the given patterns, including themself 
> also; how could I specify that the deletion should exclude the line with 
> /pattern1/, i.e. the addr is something like /pattern1/+1 ?

IF you use ed(1) style commands, then '/pattern1/+1,/pattern2/d' _is_ the
answer.  <GRIN>

See: 'man 1 ed', specifically the LINE ADDRSSING section.


That said, it is also trivial with a simple 'state machine' construct in 
awk(1):

    /pattern2/  { skipping = 0; next; }
    skipping    { next; }
    /pattern1/  { skipping = 1; next; }

Note:  omit the 'next;' from the 'pattern' line if you want that line to be
       INCLUDED in the output;
Note:  the order of the lines shown is important.


Comment: one _can_ implement something similar to the above state machine
in ed (making use of looping and conditional executin commands, and the 
'hold' buffer to track state), but it gets (*very*) messy, difficult to
maintain, and presents a 'decoding' problem for the =next= person who has
to maintain it.

_I_ find awk to be generally preferable (more easily maintainable) for 
any situation involving anything more than trivial line range specifications.