Shell Programming and Scripting

name~address~email~ID
john~newyork~john@gmail.com~1500D
steve~sydney~steve@abc.com~3451E

name~address~email~ID~rejection remark
asdddddasdddddasdddddasdddddasdddddasdddddasdddddasddddd~sanghai~wer@trd.com~D34678~name is > 50
sam~london~sam@hotmail.com~~ID is Null

while IFS='~' read n ad ml id
do 
      if (( ${#n} > 50 )); then
            echo "$n~$ad~$ml~$id~name is >50" >>rejected.dat
      else  echo "$n~$ad~$ml~$id" >>valid.dat
      fi
      if [[ -z "$id" ]]; then
            echo "$n~$ad~$ml~$id~ID is NULL" >>rejected.dat
      else  echo "$n~$ad~$ml~$id" >>valid.dat
      fi
done <abc.dat

awk -F"~" 'BEGIN{print "name~address~email~ID~rejection remark" >>"reject.dat"}
{if(length($1)>50) print $0"~name is \> 50">>"reject.dat"}
{if(length($4)==0) print $0"~ID is Null" >>"reject.dat"}' file