UNIX for Advanced & Expert Users

SN = 8
MSI = 405027002277133
IKVALUE = DE6AA6A11D42B69DF6398D44B17BC6F2
K4SNO = 2
CARDTYPE = SIM
ALG = COMP128_3
SN = 8
MSI = 405027002546734
IKVALUE = 1D9F8BAA73973D8FBF8CBFB01436D822
K4SNO = 2
CARDTYPE = SIM
ALG = COMP128_3

SN = 8,MSI = 405027002277133,IKVALUE = DE6AA6A11D42B69DF6398D44B17BC6F2,K4SNO = 2,CARDTYPE = SIM,ALG = COMP128_3
SN = 8,MSI = 405027002546734,IKVALUE = 1D9F8BAA73973D8FBF8CBFB01436D822,K4SNO = 2,CARDTYPE = SIM,ALG = COMP128_3

$ ruby -00 -ne '$_.split(/^SN/).each{|x|x.strip!;puts "SN#{x.gsub("\n",",")}" if x!=""}' file
SN= 8,MSI = 405027002277133,IKVALUE = DE6AA6A11D42B69DF6398D44B17BC6F2,K4SNO = 2,CARDTYPE = SIM,ALG = COMP128_3
SN= 8,MSI = 405027002546734,IKVALUE = 1D9F8BAA73973D8FBF8CBFB01436D822,K4SNO = 2,CARDTYPE = SIM,ALG = COMP128_3

awk 'END { print r }
r && /^SN/ {
  print r; r = x
  }  
{ 
  r = r ? r OFS $0 : $0 
  }' OFS=, infile

tr -s '\n' ',' < infile| sed -e 's/,SN/\nSN/g' -e 's/,$/\n/'

perl -lne'
  do {
    print join ",", @l;
    @l = ()
    } if @l and /^SN/;
    push @l, $_;
    print join ",", @l 
      if eof
   ' infile

#!/bin/bash

while read line
do
   if [[ $line =~ ^SN(.*) ]]
   then
      [[ -n $out ]] && echo $out
      out="$line"
   else
      out="$out, $line"
   fi
done  < infile
echo $out

while read line
do
   if [[ $line =~ ^SN(.*) ]] <-- line that starts with SN and whatever
   then
      [[ -n $out ]] && echo $out    <--when was $out defined or is it reserved?
      out="$line"
   else
      out="$out, $line"
   fi
done  < infile
echo $out