#!/usr/bin/perl
use strict;
use warnings;
use 5.010;

my %ops = ('==' => \&doEq, '=>' => \&doGe, '<=' => \&doLe, '**' => \&doStar,);
my $opMatch = join '|', map {qr{\Q$_\E}} keys %ops;

while (my $line = <DATA>) {
    chomp($line);
    my ($op) = $line =~ m{\s($opMatch)\s};

    if ($op) {
        $ops{$op}->($line);
    } else {
        print "No op found: $line\n";
    }
}

sub doEq   {my ($line) = @_; print "Do da ==: $line\n";}
sub doLe   {my ($line) = @_; print "Doing <=: $line\n";}
sub doGe   {my ($line) = @_; print "Doing =>: $line\n";}
sub doStar {my ($line) = @_; print "Process **: $line\n";}

__DATA__
1234 <= inb@it.com 
1234 <= inb@it.com 
1235 => pp <pp@nsd.net> 
1235 ++ pp <pp@nsd.net> 

##</code><code>##

Doing <=: 1234 <= inb@it.com 
Doing <=: 1234 <= inb@it.com 
Doing =>: 1235 => pp <pp@nsd.net> 
No op found: 1235 ++ pp <pp@nsd.net>