From: Al Aab <af137@freenet.toronto.on.ca>


============================ seders newsletter #2 ==============================

SED PROBLEM #1

There was that arcane language called BASIC. Here is a statement in BASIC :-

    DRAW "U" : IF P THEN DRAW " U  u  DLrR D LRR D R LL  " : GOTO L

The problem is to beautify the input, using a general sed script, by removing
the blanks between the second double-quote pair. The result should be:

    DRAW "U" : IF P THEN DRAW "UUDLRDLRRRDRLL" : GOTO L

                                     - + -

SED PROBLEM #2

Given a book divided into big chapters, each chapter may be too big to fit in
sed's RAM buffers (the pattern space & the hold space). Each chapter starts
with a line of 3 dashes, chapter n, and another 3 dashes.

How can you select all the chapters that contain "pattern"?

Here is a sample input file to work with:

---cut here---------------------------------------------------------------------
---
chapter 1
---
... pattern --
line 1.1
line 1.2
---
chapter 2
---
line 2.1
   pattern @#$
line 2.2
---
chapter 3
---
line 3.1
line 3.2
---
chapter 4
---
line 4.1
line 4,2
!#@$pattern
(*&^
---cut here---------------------------------------------------------------------

I posted the above problem to comp.editor, comp.unix.programmer, 
comp.unix.questions and maybe comp.unix.wizards.

In sed, I have yet to get a satisfactory answer, but did get some interesting
ones:

From Berlin, Germany:

    Use agrep -k

From Austria:

    Use csplit to split the input file into separate chapters,
    and grep to select the files that contain the pattern.

I managed to solve that problem in 2 ways. One way using sed, sort, cat, tac.
Another solution used about 3 lines of sed. Removing the constraint that
the chapters may overflow sed buffers, I had come up with an earlier, easier
sed solution.

Send your solutions, ideas, insights, questions,etc.

If you want to take over as seders coordinator, you're welcome.

sed u soon
al aab
seders coordinator
af137@torfree.net
20 August 1996

--
   no dat v no c solution
      DAT v no c 
problema

========================= end of seders newsletter #2 ==========================