Extract sequence blocks

Shell Programming and Scripting
1

Hi,

I have an one-line file consisting of a sequence of 660 letters. I would like to extract 9-letter blocks iteratively:

ASDFGHJKLQWERTYUIOPZXCVBNM

first block: ASDFGHJKL
1nd block: SDFGHJKLQ

What I have so far only gives me the first block, can anyone please explain why?

cat file | awk '{pep=""; for (i=0; i<=NF; i++); (pep=substr($0,i,9)); {print pep}}'

Cheers,
S

2

"man fold"

Thanks
SHa

3

Well the problem with "fold" is it (as the name hints) only folds my sequence and gives me 9-letter long blocks.

What I need is to go through the line, letter by letter, and extract 9-letter long blocks...

But thanks anyway, fold with surely be useful to me in the future!
/S

4

how's that different from what 'fold' provides?

5

Let's say my line is: 123456789123456789123456789

fold gives me:
123456789
123456789
123456789

but I need:
123456789
234567891
345678912

6

ah, ok:

echo '123456789123456789123456789' | nawk -v len=9 '{l=length; for(i=1;i<=l-len+1; i++) print substr($0,i,len)}'
7

Thanks!

8

perl

$str="ASDFGHJKLQWERTYUIOPZXCVBNM";
$tmp=reverse $str;
$tmp=~s/(?=(.{6})+$)/_/g;
$tmp=reverse $tmp;
print $tmp;