bash로 vlookup 구현

https://sancs.tistory.com/6

https://unix.stackexchange.com/questions/88550/vlookup-function-in-unix

BEGIN{FS=OFS=","}
FNR==NR{
  a[$1]=$2
  next
}
{ if ($1 in a) {print $1, a[$1]} else {print $1, "NA"}  }