Help with Checking Strings for new lines

rosh

I'm trying to put some security on 'Send email form'. So I need to detect any new line characters in $subject.
The code I'm using doesn't give any results.

<?php
$subject = $_POST['Subject'];

if(empty/COLOR)
{
echo '<form method="post" action="">
<input type="text" name="Subject" size="20" />
<input type="submit" value="Submit" />
</form>';

}else{

if (eregi("\r", $subject) || eregi("\n", $subject)) {die("new line found");}

echo "CLEAR";
}
?>

Using other scripts for this purpose gives me the same.
Seems like the problem lies in $_POST because if I state directly - $subject = "try";
everything works perfectly.
I'd appreciate if anyone can help.
Thanks.

nrg_alpha

First, I would recommend ditching ereg as POSIX will not be inlcuded in the core as of PHP 6 and later. Best to future proof yourself now by using PCRE (think preg).

if(preg_match('#[\r\n]#', $subject)){
    die("new line found");
} else {
    // do whatever
}

rosh

Thanks very much for quick reply. I've tried that just now. Still same results. Sorry.

bradgrafelman

Not sure how you're testing it or what's going wrong, then; the following worked as expected when I tested it:

<?php
if(empty($_POST['Subject'])) {
	echo '<form method="post" action="">
	<textarea name="Subject" size="20"></textarea>
	<input type="submit" value="Submit" />
	</form>';
} else {
	if(preg_match('#[\r\n]#', $_POST['Subject'])) {
			die("new line found");
	} else {
			// do whatever
	} 

echo "CLEAR";
}
?>

nrg_alpha

Ooops.. I inserted $subject as the variable for preg to check against, as I saw that variable in his code, only to now realize it is supposed to be $_POST['Subject']. My bad.

@, I tested Brad's example, and as he also notes, it functions just fine. I'm not sure why it wouldn't work for you.