#!/bin/bash

MergedFile=$1
DefaultFile=$2
ProjectFile=$3

gawk 	'BEGIN{FS=OFS=",";Pass=0; count=0;}
		Pass==1 && NF==4{records[$1]=$0; count++; order[count]=$1;}
		Pass==2 && NF==4{records[$1]=$0;}
		END{for (i=1; i<=count; i++) print records[order[i]];}' Pass=1 $DefaultFile Pass=2 $ProjectFile | tee $MergedFile;