Please help on this preg_match

[jeddiki]

Hi,

I am using the following regex to check for valid email
addresses, but I am getting errors.

if (preg_match('\^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$\',$regex)){
       echo "VALID";
     }
else {
     echo "INVALID";
    }

The errors that I get are:

Warning: Unexpected character in input: ''' (ASCII=39) state=1 in /home/guru54gt5/public_html/im/regex.php on line 6

Warning: Unexpected character in input: '\' (ASCII=92) state=1 in /home/guru54gt5/public_html/im/regex.php on line 6

Parse error: syntax error, unexpected '^', expecting ')' in /home/guru54gt5/public_html/im/regex.php on line 6

Line 6 refers to the if stmt line in my script.

I took the example from a tutorial and I thought that I understood everything, but I can not
see why this is causing errors :)


PS I changed the single quotes to double:
if (preg_match("\^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$\",$regex)){

and now I get just one error:
Parse error: syntax error, unexpected T_STRING in /home/guru54gt5/public_html/im/regex.php on line 7

But, again, I do not see why
Thanks for any help.

[jeddiki]

OK,
I have seen my mistake,
I changed backslashes to forward slashes at the perimeters.
Now it works OK

BUT now I am confused by my results.

I am using a simple form to input to this script:

<?php 
if( isset($_POST['x_regex'])) {
   $regex = "{$_POST['x_regex']}";
     if (preg_match("/^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/",$regex)){
       echo "VALID";
         }
        else {
          echo "INVALID";
        }
}
else {
require("regex_fm.php");
}
?>

When I enter this: [e-mail]
It comes up as valid - but the number 4 should
get it thrown out - why doesn't it ?

and how can I make it do it ?

Thanks

[Dormilich]

why should the number 4 get thrown out?

[jeddiki]

OK - you are correct - it shouldn't

So that validation is OK

Now I am also doing a URL validation:
This is more complicated because I am using preg_replace

I am trying to find a url withing the text and convert it to a
hyper link.

So I need to collect the parts of the url and stick them
together

First bit is to check to see if http or https
If the http is not there I need to add it at the beginning of the result

So my code is now

<?php 
if( isset($_POST['x_regex'])) {
   $regex = "{$_POST['x_regex']}";
     $new_url = preg_replace("@((https?://)?([-\w]+\.)+(-\w{2,})+(:\d+)?(/([-\w/_\.]*(\?\S+)?)?)?)@", '<a href="$1">$1</a>', $regex);
      $new_url ="<a href=".$new_url."<a>"; 
     echo "<br><br>URL:  $new_url";
     echo "<br><br><a href=\"http://www.expert-world.com/im/regex.php\">Try Another<a>";
     exit;
}
else {
require("regex_fm.php");
}
?>
 

I am a bit stuck.

The testing page is here

BTW - I got this validation from the a google search can
someone tell me why this included: (:\d+)
what does that colon do ?

[kovik]

You should probably take the time to actually teach yourself regex. A good learning tool is The Regex Coach. It lets you see how the regex works as you type it.

Anyway, the colon is not a special character. It is a port number, like http://www.google.com:80/ (80 is the public port).

[Dormilich]

(80 is the public port)

it is rather the default (HTTP) server port. if you have configured your server correctly, you can use any valid port you want.