Shell Programming and Scripting

1~2~~4
2~6~~7
3~8~~9

1~2~~4
2~5~8~7
3~8~~7

KEY~DIS~NOT~KAT

paste -d '~' s.txt t.txt | awk -F '~' '{c=NF/2;for(i=1;i<=c;i++)if($i!=$(i+c))printf "line %-5s field %s orginal %s changed  %s\n",NR,i-1,$i,$(i+c)}'

line 2     field 1 orginal 6 changed  5
line 2     field 2 orginal  changed  8
line 3     field 3 orginal 9 changed  7

KEY~COLUMNNAME~SOURCEVALUE~TARGETVALUE
2  ~ DIS      ~   6       ~    5
2  ~ NOT      ~          ~     8
3  ~ KAT      ~    9     ~     7

awk -F'~' -v header="$(<header.txt)" 'BEGIN{OFS=" ~ ";split(header,h)
print "KEY","COLUMNNAME","SOURCEVALUE","TARGETVALUE"}
FNR==NR{for(i=1;i<=NF;i++) e[FNR,i]=$i;next}
{for(i=1;i<=NF;i++) 
  if($i!=e[FNR,i])
   print FNR,h[i],e[FNR,i],$i
}' s.txt t.txt