#!/usr/bin/env bash

# @(#) s1	Demonstrate re-arrangement with paste, sed, align.
# align: http://freecode.com/projects/align

# Section 1, setup, pre-solution, $Revision: 1.25 $".
# Infrastructure details, environment, debug commands for forum posts. 
# Uncomment export command to run script as external user.
# export PATH="/usr/local/bin:/usr/bin:/bin" HOME=""
set +o nounset
pe() { for _i;do printf "%s" "$_i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
db() { : ; }
db() { ( printf " db, ";for _i;do printf "%s" "$_i";done;printf "\n" ) >&2 ; }
C=$HOME/bin/context && [ -f $C ] && $C paste sed align
set -o nounset
pe

FILE=${1-data1}

# Display sample of data file, expected output:"
db " Section 1: display of data."
head $FILE expected-output.txt

# Section 2, solution.
pl " Results:"
db " Section 2: solution."
title=$( pe " apple banana cherry" | sed 's/  */\t/g')
paste - - - - < $FILE |
tee t1 |
sed -r 's/apple|banana|cherry//g' > t2
( pe "$title" ; cat t2 ) |
align -st |
tee f1

# Section 3, post-solution, check results, clean-up, etc.
v1=$(wc -l <expected-output.txt)
v2=$(wc -l < f1)
pl " Comparison of $v2 created lines with $v1 lines of desired results:"
db " Section 3: validate generated calculations with desired results."

pl " Comparison with desired results:"
if [ ! -f expected-output.txt -o ! -s expected-output.txt ]
then
  pe " Comparison file \"expected-output.txt\" zero-length or missing."
  exit
fi
if cmp expected-output.txt f1
then
  pe " Succeeded -- files have same content."
else
  pe " Failed -- files not identical -- detailed comparison follows."
  if diff -b expected-output.txt f1
  then
    pe " Succeeded by ignoring whitespace differences."
  fi
fi

exit 0

% ./s1

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Linux, 2.6.26-2-amd64, x86_64
Distribution        : Debian GNU/Linux 5.0.8 (lenny) 
bash GNU bash 3.2.39
paste (GNU coreutils) 6.10
sed GNU sed version 4.1.5
align 1.7.0

 db,  Section 1: display of data.
==> data1 <==
Kapil:
apple 4
banana 6
cherry 0
Manoj:
apple 13
banana
cherry 2

==> expected-output.txt <==
         apple banana cherry
Kapil:    4       6      0
Manoj:    13             2

-----
 Results:
 db,  Section 2: solution.
	apple	banana	cherry
Kapil:	 4	 6	 0
Manoj:	 13		 2

-----
 Comparison of 3 created lines with 3 lines of desired results:
 db,  Section 3: validate generated calculations with desired results.

-----
 Comparison with desired results:
expected-output.txt f1 differ: char 1, line 1
 Failed -- files not identical -- detailed comparison follows.
 Succeeded by ignoring whitespace differences.