UNIX for Dummies Questions & Answers

FILE 1          FILE 2
ABC  011        ABC 012
DEF  021        XYZ o42

       FILE 1    FILE 2
ABC    011       012
DEF    021         0
XYZ     0         042

#!/bin/bash
nawk 'NR==FNR {
if ($1 !~ /^963/)
{
t[$1]=$2
m[$1]=$0
}
}
NR!=FNR{
if ($1 !~ /^963/)
{
if (t[$1]!="")
t[$1]=sprintf("%s %s",$0,t[$1])
else
t[$1]=sprintf("%s 0",$0)
}
}
END{
for (i in t)
if(index(t[i]," ")!=0)
        print t[i]
else
        print m[i]
}' $2 $1

awk 'BEGIN {print "Col A  File 1  File 2"}
     FILENAME=="file1" {arr[$1]=$2}
     FILENAME=="file2" {
       if($1 in arr) {
          # handle those in both files
          print $1, arr[ $1 ], $2; 
          delete arr[$1]
       }
       else { 
          # handle those not in file1
          print $1, "0", $2
       }     
     } 
     # handle those not in file2
     END {for (i in arr) {print i, arr[i], 0 }}'   file1  file2 > newfile