Sorting and grouping question

Hi,
here is a problem I'm working on. It's not PERL-specific, rather it is a
problem in sorting followed by grouping.
Suppose I have a set of lines that have tab-delimited text, thus:
1  w   3   wer
2  a   4    rte
4  w   2    weg
6  d  4    fhg
5  d   7   dfl
6  w   4   ald
8  a   3   dsl

I would like to first sort the lines based on the 2nd token (w,a, w, d, etc)
and then group the lines based on the 2nd token.

At the end of this sorting/grouping I should have the lines grouped thus:
2  a   4    rte
8   a   3   dsl

6   d  4    fhg
5   d   7   dfl

1  w   3   wer
4  w   2    weg
6  w   4   ald


I can figure out the sorting. Are they any command/modules to do the
grouping based on identical tokens?

appreciate your input.


tia,
anjan



-- 
ANJAN PURKAYASTHA, PhD.
Senior Computational Biologist
==========================

1101 King Street, Suite 310,
Alexandria, VA 22314.
703.518.8040 (office)
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email:
anjan@vbi.vt.edu;
anjan.purkayastha@gmail.com

http://www.vbi.vt.edu

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• Sorting and grouping question by ANJAN PURKAYASTHA
• Re: Sorting and grouping question by Li, Jialin