Filter Text from the form using php

**Rockonmetal** · 10-18-2007, 08:18 PM

I have this suggestion form but I don't want people to swear and stuff cuz I put up one last night and I got 350 bad words, links, advertisements, and a whole bunch of stuff...
But anyways I don't know how to filter through words and to see if a variable is too long using strings...
I have the code below of the page...

Code:

<html>
<head>
<style type="text/css">
html,body{
	font-family: Trebuchet Ms;
	font-size: 12px;
}
.input{
	width: 200px;
	border: 1px solid #4e4e4e;
	padding-left: 3px;
	font-family: Trebuchet Ms;
	font-size: 16px;
	font-weight: bold;
	background-color: #FFFFFF;
}
.textarea{
	width: 350px;
	height: 100px;
	border: 1px solid #4e4e4e;
	padding-left: 3px;
	font-family: Trebuchet Ms;
	font-size: 13px;
}
</style>
</head>
<body>
<form action="193.php" method="post" />
<br />Your Display Name:
<br /><input type="text" name="1" class="input"/>
<br />
<br />Your Message:
<br /><textarea class="textarea" name="2"></textarea>
<br />
<br /><input type="submit" class="input" />
</form>
<?php
$dName = $_POST["1"];
$Message = $_POST["2"];
?>

If you explain what to put where and how to edit it pretty well then I can do it... or if you feel that you could just write the code yourself faster than doing that it's fine, it's your choice...

**djr33** · 10-18-2007, 09:24 PM

Well, you need to think about specifically step by step how to alter the text.
A simple bad word filter is incredibly simple... just replace [word] with [] or [****], etc.

$string = str_replace('findword','replaceword_orblank',$string);

Efficiently, you could use an array-- array('word1','word2','word3') -- and place the replace within a foreach loop, removing each word.

You may also want to consider placement-- hello contains hell; you may want to check that there is a space or other punctuation on either side of the word.

Replacing links wouldn't be all that hard--
You could use regex, or you could use a less efficient/simpler (but more complex statements) method with substr, etc.

PHP Code:


while (strpos('http://',$string)!==FALSE) {
$string = substr($string,0,strpos($string,'http://')).substr($string,strpos($string,' ',strpos($string,'http://'));
}

(Can't promise that'll work, but the concept is there-- and you should consider if that's exactly what you want anyway.)

And you can do some more, as well, though nothing you will do can get around human creativity, so you'll need to manually check the posts... yep. Ban those who post offensive comments if possible, as well.

A simple captcha or even just a question "what color is grass? [blue] [red] [green]" would also help with bots.
Your security doesn't need to be perfect if there isn't a real threat-- just some spam, and it is likely that the bots will give up rather than adapt as your site probably is not any particular benefit to them... they just search out forms and post.

**Rockonmetal** · 10-18-2007, 09:29 PM

K, thanks man I'll try it out... I'll try the string out and I don't feel comfortable with it I'll try the array out... thanks...

**djr33** · 10-18-2007, 09:43 PM

If you want a lot of words, the array is absolutely the best method. For just a few, lines of code would work.

**Twey** · 10-18-2007, 09:55 PM

Efficiently, you could use an array-- array('word1','word2','word3') -- and place the replace within a foreach loop, removing each word.

No need to loop, str_replace() takes arrays:

Code:

str_replace(array('monkeys', 'fish'), array('*******', '****'), $str);

**djr33** · 10-18-2007, 10:05 PM

Ah. Very nice. I'd say don't use a second array, then; just use an empty string or '****', which would be the same value for every element of the other array.
I don't see the point in having a separate replace value for each item, though perhaps you'd like the right number of asterisks, though that would make the original word more clear.