problem with preg_match

[Kerflumper]

I'm trying to setup an email form on a Godaddy server but it doesn't seem to like my preg_match functions (the form works otherwise, btw). I have the identical script on other servers with no issue. Here are the relevant snips:

$firstname=$_POST['firstname'];
$safefirstnamepattern = "/^[a-z \-.'()]+$/i";
if (preg_match($safefirstnamepattern,$firstname) === 0) {
	echo '<META HTTP-EQUIV="Refresh" Content="0; URL=formerror.php">';
		exit();
	 }

The message I get is Warning: preg_match() [function.preg-match]: Unknown modifier ']'

What's wrong here?

 

[Kerflumper]

I posted the wrong pattern that was causing the error. The correct pattern is "/^[a-z0-9 \-,.:?'()/]+$/i". Do I have a / in the wrong place?

 

[jaxtell]

I think you should be escaping the special characters, including the slash in the middle of your expression.

-----------------------------------------
I cannot be bought. Find leasing information at

http://www.joshaxtell.com/

 

[Kerflumper]

My understanding was that the \ was escaping the -. I changed the pattern to "/^[a-z0-9 \-,.:?'()]+$/i" and the error went away. Hopefully that was the problem and it will work as it should.

 

[jpadie]

you do not need to escape characters in a character class.

the problem in your first post was the it was enclosed in double quotes rather than single quotes. so php was trying to expand the dollar sign as a variable.

 

[Kerflumper]

jpadie: I got the example from one of your other posts at

http://www.tek-tips.com/viewthread.cfm?qid=1456784

where you had specified full quotes and escaped the -.

But I guess the real solution is to use single quotes. I wonder why this works ok on other servers.

 

[sen5241b]

Consider using preg_quote

 

[jpadie]

you are quite right that the dash DID need escaping as per my referred post. the php manual says

All non-alphanumeric characters other than \, -, ^ (at the start) and the terminating ] are non-special in character classes, but it does no harm if they are escaped. The pattern terminator is always special and must be escaped when used within an expression.

My feeling is that the dollar sign was causing problems but the error message you were getting does not actually point to that.