Shell Programming and Scripting

 cat filea | while read x; 
do 
grep $x fileb >/dev/null 
echo $?; 
if [ "$?" = "1" ] 
then
echo "Error, $x not resident"
fi
done

#!usr/bin/perl
use strict; 
use warnings;
use Data::Dumper;
use vars qw ( @FA $lineinfilea );
open (iFILEA, "<filea") or die;
@FA = <iFILEA>;
close iFILEA;
#
open (iFILEB, "<fileb") or die;;
@FB = <iFILEB>;
close iFILEB;
#
foreach $lineinfilea  (@FA) {
 chomp $lineinfilea;
 print $lineinfilea, "\n";
   #PSEUDO code 
   #grep $lineinfilea @FB
   #  if the exit status of grep $linefilea @FB is 1 
   #   then  
   #   print $lineinfilea, "is not resident.\n;
   #
}

#! /usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
my $lineinfilea;
my @FA;
my @FB;
open (iFILEA, "<filea") or die;
@FA = <iFILEA>;
close iFILEA;
#
open (iFILEB, "<fileb") or die;
@FB = <iFILEB>;
close iFILEB;
#
foreach $lineinfilea  (@FA) {
 chomp $lineinfilea;
 print $lineinfilea, "\n";
 if ( $lineinfilea ~~ @FB ) {
   print "The array contains $lineinfilea\n";
 } else {
  print "The array doesnt contain $lineinfilea\n";
 }

awk 'NR==FNR {a[$1]; next} !($1 in a) {printf "Error, %s not resident\n",$1}' fileb filea

#!/usr/bin/perl -w
my %FB;
open (Fb, "<fileb") or die;
while (<Fb>) {
  chomp;
  $FB{$_}="";
}
close Fb;
open (Fa, "<filea") or die;
while (<Fa>) {
 chomp;
 print "Error, $_ not resident\n" unless exists $FB{$_};
}
close Fa;