how to check email with regex expression code example

Example 1: email regex

(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])*")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e-\x7f])+)\])

Example 2: regex validate email

# Language: Perl

sub Validate_Email($)
{
   my $sEmail = $_[0];
   my $sRetMsg = "";

   my $sUserNmRegex = "^[[:alnum:]]+([.!#\$\%&'*+-\/=?^_'{|]?[[:alnum:]]+)*";
   my $sDomainRegex = "@[[:alnum:]]+([.-]{1}[[:alnum:]]+)*";
   my $sEndRegex = "([.]{1}[[:alnum:]]+)+";

   #  Work
   #--------#

   if ($sEmail =~ /$sUserNmRegex$sDomainRegex$sEndRegex$/) {
      $sRetMsg = "Email is valid";
   }
   else {
      $sRetMsg = "Email is not valid";
   }

   return $sRetMsg;
}

my $sEmail = '[email protected]';
print "[Email:$sEmail] : " . Validate_Email($sEmail) . "\n";

# OUTPUT -> [Email:[email protected]] : Email is valid