Matching Email Address

saeed42

I have flat file db that contains about 3000 email addresses, the problem is the script we used to use to collect the email address didn't validate the email addresses hence we have at least 20% of the addresses which are not even in a correct format, so my task is to write a small PHP script which will read the text file and print those email addresses that are at least in correct format on to the browser.

BE WARNED THIS CODE IS NOT PRETTY AS I'M A BEGGINNER


<?
$fp = fopen("maillist.dat", "r");
$temp_emails = fread($fp, 100000000);
$emails = explode("\n", $temp_emails);

$numb_array = count($emails);
	for($i = 0; $i < $numb_array ; $i++)
	if(eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $emails)) 
   {
	print (strtolower("$emails[$i]". "<BR />"));  

	}

fclose($fp);


?>

This code produces a blank page and I'm not quite sure why

Moonglobe

if(eregi("^[_a-z0-9-]+(.[_a-z0-9-]+)*@[a-z0-9-]+(.[a-z0-9-]+)*(.[a-z]{2,3})$", $emails))

change that to

if(eregi("^[_a-z0-9-]+(.[_a-z0-9-]+)*@[a-z0-9-]+(.[a-z0-9-]+)*(.[a-z]{2,3})$", $emails[$i]))

saeed42

Thanks, it worked as you expected.

Here is the code just in case anyone out there finds it useful. The code also checks whether the email address has a valid MX record or not, but it doesn't check if that person has an account.

<?
//Open file 
$fp = fopen("maillist.dat", "r");
	if(!$fp) {
   print "error! The file could not be opened";
   exit; }
//Read the file and explode the string into array
$temp_emails = fread($fp, 100000000);
$emails = explode("\n", $temp_emails);
$numb_array = count($emails);

//Print those email addresses with correct format and valid MX record into the browser	
for($i = 0; $i < $numb_array ; $i++)
	if(eregi("^[_a-z0-9-]+(.[_a-z0-9-]+)*@[a-z0-9-]+(.[a-z0-9-]+)*(.[a-z]{2,3})$", $emails[$i])) {
   list ( $Username, $Domain ) = split ("@",$emails[$i]); 
   if (getmxrr($Domain, $MXHost))  {
	print (strtolower("$emails[$i]". "<BR />"));  

	}
}
fclose($fp);

?>

I have one more question, how can I delete a string from a text file i.e. one email address.

One way I can think of is to grab the whole file and overwrite the file with the data minus the string I want to delete, I think this's not very efficient so I was wondering if there's a more efficient way of doing it

tekky

I'm fairly certain PHP doesnt support line editing/deleting in files w/o completely rewriting the file....

I would handle this by writing a temp file, ensuring its valid, then deleting original/moving temp to its name...

saeed42

What would you do if the file is too large?

tekky

Originally posted by saeed42
What would you do if the file is too large?

uhm define too big.... cant fit 2 copies on the website?

if its too big to process quickly enough for your standards... maybe you should export it to a DB instead....

saeed42

Way too big to be processed quickly, especially to rewrite every time something is to be deleted. We are planning to move everything to a db, but I just wanted to see how the experts would deal with such a scenario.

Moonglobe

weeeeell...........there's always [man]fseek[/man] if you're really adventurous.

tekky

you do understand that if you were deleting 20 values out of the file.... (in one processing attempt on the file that is) it will still ONLY be rewrittin ONCE?

(almost sounds like you understand it to mean each line deleted == rewriting the file, where as its only rewritten each time the script is ran IF lines are deleted)

Moonglobe

actually, you don't need a tamp file. just keep it in memory.

<?php
$file_emails = file('email.x');
$emails = array();
foreach ($file_emails as $email) $emails[] = trim($email);
foreach ($emails_to_delete as $email_to_delete)
{
    if ($key = array_search($email_to_delete,$emails))
    {
        unset($emails[$key]);
    }
}
$fp = fopen('email.x','w');
fwrite($fp,'');
foreach ($emails as $write_email)
{
    if (isset($write_email) && $write_email)
    {
        fputs($fp,$write_email);
    }
}

hth
moon

tekky

I suggest that so he wouldnt lose data if the file dumped wrong 😉

saeed42

Thanks Guys, with the help of people like I'm sure learning PHP will not be that difficult.

saeed42

I'm once again in need of your help. I decided to write a newsletter subscription script, I know there are plenty of them
out there, but if I keep using other peoples' scripts all the time
than I'm never going to learn PHP.

I want the script to do the following
Validate the email address
Not to allow any email address with our domain
Check for the existence of MX record
Check for duplicates

I have problem with checking for duplicates, it will only read the
first line in the flat text file and if that is the same it will say "email
already in db" but if the same email address was further in the
file i.e. line 20 it would just add the email address and it will just
keep adding, it's like it's only comparing to the first line and then
it's exiting the
loop



$email = trim(strip_tags($_POST['email']));

#Validate email address

if(isset($_POST['Submit']) && (!eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$", $email))){
		print "Your e-mail address appears to be in 
an invalid format, or is not entered. Please close this window, 
check your e-mail address in the subscribe box and try again."; 
		exit;
		}

#Make sure email address is not from our domain

if(eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@ourdomain(\.[a-z]{2,3})$", $email)){
		print ("<B> This email address doesn't seem to exist on ourdomain.com Servers </B>"); 
		exit;
} 

#Check for MX record

if(isset($_POST['Submit'])) {
	list( $Username, $Domain ) = split ("@",$email); 
   		 if (!getmxrr($Domain, $MXHost)){
	  	  print("Email address domain cannot be found on the internet ");
		  exit;
	  }
  }

// Check if email address is in the db
$fp = fopen("emailst.txt", "a+");
	if(!$fp) {
   print "Error! The file could not be opened";
   exit; }

//Read the file and explode the string into array
if(!empty($email)){
	$temp_emails = fread($fp, 1024); 
	$array_emails = explode("\r", $temp_emails);
	$numb_array = count($array_emails);
	foreach($array_emails as $list_emails) {
	if(eregi("^$email(\r|\n)*", "$list_emails")){
	print("<B>$email Exists in db</B>"); 
		exit;
			}
		}

fwrite($fp, "$email"."\r\n");
		if(!$fp) {
			print "error! Couldn't write your email address to the db";
			exit; }
			else{
			print "Your email address is added to our db";
			exit;
			}

fclose($fp);
 }