Shell Programming and Scripting

#!/bin/sh

# rm-quotes.sh NFIELD (from 1)

NFIELD=$1

INSIDE=0

while read s; do
    for ch in `echo $s | sed 's/./& /g'`; do
        case $ch in
               ,) [ $INSIDE -eq  0 ] &&  echo , || echo ' ' ;;
              \") INSIDE=$((! $INSIDE)); echo $ch ;;
             ' ') : ;;
               *) echo $ch ;;
        esac
    done | 
        tr -d "\n" | 
        awk -F, '{ 
                    gsub(" ", "", $'$NFIELD') 
                    gsub(" ", ",")
                    print 
                 }'
done

% ./rm-quotes.sh 1 < testfile
first,"Street1,City1,Country1",test1
second,"Street2,City2","test2"
third,"Street3,City3,Country3","A,B,C,D,E"
fourth,"A,B,C,D,E",test4"

% ./rm-quotes.sh 2 < testfile
first,"Street1City1Country1",test1
second,"Street2City2","test2"
third,"Street3City3Country3","A,B,C,D,E"
fourth,"ABCDE",test4"

% ./rm-quotes.sh 3 < testfile
first,"Street1,City1,Country1",test1
second,"Street2,City2","test2"
third,"Street3,City3,Country3","ABCDE"
fourth,"A,B,C,D,E",test4"