php Preg Match Expression

Hi,

I'm trying to take the user input from a form, scan the comment for:

[quote]12[/quote]

HTML:

And then perform a mysql query with that Id numbder.

However I'm struggling getting the preg_match to find the number, here's what I have.

I realise it's not secure yet but I'm just testing at the moment.

	preg_match_all('~[quote][0-9][/quote]~i', $comment, $matches);
		
		foreach ($matches[1] AS $match)
		{
			if($match != '')
			{
			$result = mysql_query("SELECT message FROM forumPosts WHERE id='$match'");
			$row = mysql_fetch_row($result);
			$comment = "$row[0]<br />$match<br />$comment" ;
			}
		}

PHP:

I think the expression in the Preg_match may be wrong?

Thanks
Dan

 

First thing I noticed - it won't match 12 because you've only allowed for the numbers 0 - 9, to get it to match double digit numbers you'll need to put [0-9][0-9]. To have it match unlimited numbers of digits, put [0-9]*

Also, you need to delimit the [ and ] characters that aren't meant to contain an expression, put a backspace before them.

You also need to change 'foreach ($matches[1] AS $match)' to 'foreach ($matches[0] AS $match)', unless you only want it to work for the second quote tag.

preg_match_all('~\[quote\][0-9][0-9]\[/quote\]~i', $comment, $matches);
       
        foreach ($matches[1] AS $match)
        {
            if($match != '')
            {
            $result = mysql_query("SELECT message FROM forumPosts WHERE id='$match'");
            $row = mysql_fetch_row($result);
            $comment = "$row[0]<br />$match<br />$comment" ;
            }
        }

PHP:

Or to have it match unlimited numbers of digits:

preg_match_all('~\[quote\][0-9]*\[/quote\]~i', $comment, $matches);
       
        foreach ($matches[1] AS $match)
        {
            if($match != '')
            {
            $result = mysql_query("SELECT message FROM forumPosts WHERE id='$match'");
            $row = mysql_fetch_row($result);
            $comment = "$row[0]<br />$match<br />$comment" ;
            }
        }

PHP:

If you mean to have it display all of the quote tags entered, you need to put something like this:

preg_match_all('~\[quote\][0-9]*\[/quote\]~i', $comment, $matches);
       
        foreach ($matches AS $matches_mini)
        {
                foreach ($matches_mini AS $match)
                {
                    if($match != '')
                    {
                    $result = mysql_query("SELECT message FROM forumPosts WHERE id='$match'");
                    $row = mysql_fetch_row($result);
                    $comment .= "$row[0]<br />$match<br />$comment<br />" ;
                    }
                }
        }
        }

PHP:

 

Thanks for that this is great help, However this returns a match of:

[quote]12[/quote]

HTML:

I could just strip the quote tags from the match but if it's possible to match without the quote tags that would help greatly.

Thanks in advance.

 

I expect it's possible, but I'm not sure how really, without just matching any numbers at all. As you say, for now just strip the tags using a custom function doing str_replace and then array_map -ping that to $matches.

 

preg_match_all('~\[quote\]([0-9]*)\[/quote\]~i', $comment, $matches);

// $matches[1] will hold the number only

PHP:

(Note the parenthesis.)

 

Ok thanks again,

Now i'm seeing another problem, if a user inputs:

 [quote]12[/quote] [quote]13[/quote] [quote]14[/quote]

HTML:

Then it will just return:

<q>User:<span>Comment</span></q>

HTML:

and then not get 13 or 14, but I need to make a loop so it builds the comment up,

I know the following won't work but it's just showing the basic idea of how I need it too function.

$comment = $match[0] + [$match[1];

PHP:

The current code i'm using is as follows:

		preg_match_all('~<q>([0-9]*)</q>~i', $comment, $matches);
		foreach ($matches[1] AS $match)
		{
			if($match != '')
			{
			$result = mysql_query("SELECT message, username FROM forumPosts WHERE id='$match'");
			$row = mysql_fetch_row($result);
		
			$comment = "<q><span>$row[1]:</span> $row[0]</q>" ;
			}
		}

PHP:

 

preg_match_all('~<q>(\d+)</q>~i', $comment, $matches);
$ids = array_unique($matches[1]);

$query = mysql_query("SELECT `message`, `username` FROM `forumPosts` WHERE `id` IN(" . implode(', ', $ids) . ")") OR die(mysql_error());
$comment = '';

while ($row = mysql_fetch_row($query))
{
	$comment .= "<q><span>$row[1]:</span> $row[0]</q>";
}

echo $comment;

PHP:

Faster and shorter.

 

Ok, is there a way to only do everything after the perg_match if there is a match?

else just skip the rest and continue on.

 

$comment = '';

if (preg_match_all('~<q>(\d+)</q>~i', $comment, $matches))
{
    $ids = array_unique($matches[1]);

    $query = mysql_query("SELECT `message`, `username` FROM `forumPosts` WHERE `id` IN(" . implode(', ', $ids) . ")") OR die(mysql_error());

    while ($row = mysql_fetch_row($query))
    {
        $comment .= "<q><span>$row[1]:</span> $row[0]</q>";
    }

    echo $comment;
}

PHP: