Shell Programming and Scripting

Alpha    156
Beta     255
Gama    6987
segma   4578

Alpha    156
Beta     255
Gama    1000
segma   4578

Gama 1000

awk 'NR==FNR{A[$1]=$2;next}$1 in A&&$2!=A[$1]' file1 file2

use strict ;

my $infile1 = q[File1];
my $infile2 = q[File2];
my %_1 = () ;
my %_2 = () ;
my %_3 = () ;

#now firstfill...

open (I, '<' . $infile1) or die @! ;
open (II, '<' . $infile2) or die @! ;

while (<I>) {
 chomp ;
 m/^(.+?)\s+([0-9\+\-]+)$/ ;
 $_1{$1} = $2 ;
 m/./; #reset regex
}

while (<II>) {
 m/./ ; #reset regex
 chomp ;
 m/^(.+?)\s+([0-9\+\-]+)$/ ;
 $_2{$1} = $2 ;
}

#fill....

push %_3, map { ($_, $_2{$_}) } grep { $_1{$_} != $_2{$_} } keys %_2 ; 

#now report ...

print qq[\n], $_, qq[\t\t], $_3{$_} for sort keys %_3 ;