filter form input for illegal chars

I want to filter / reject the following chars from form input: ' (which seems to be the most difficult) - _ (the last 2 I have some success with)

I've tried \' but that doesn't seem to do any good.

Any help? Thanks.

 

You need to remove this chars? If so:

$a = str_replace($a, "'", '');

Code (markup):

 

I think it should be:

$a = str_replace("'", '', $a);

Code (markup):

Thanks

 

farooqaaa, yes, of course - sorry.

 

Thanks for the quick response. When I try to use your suggestion, it filters everything (so I get no results).
Any ideas?

$SearchString = str_replace($SearchString, "'", ' ');
$SearchString = trim($SearchString);
$SearchString = preg_replace('/\s\s+/', ' ', $SearchString);

 

Should be:

$SearchString = str_replace("'", '', $SearchString);
$SearchString = trim($SearchString);
$SearchString = preg_replace('/\s\s+/', ' ', $SearchString);

Code (markup):

There is mistake in my first post.

 

Swapping $SearchString to the end of the list fixed it. Thanks guys! =)

 

Can I do multiple replacements in the same statement, or do I have to issue the statement over and over again to clean everything out?

Say I want to get rid of _ - ' etc.?

 

You can create function:

function cleanOut($SearchString)
{
$SearchString = str_replace("'", '', $SearchString);
$SearchString = trim($SearchString);
$SearchString = preg_replace('/\s\s+/', ' ', $SearchString);
return $SearchString;
}

$text = cleanOut( $text );

Code (markup):

 

Ok, works for me. Thanks again guys. =)

 

Ok, one last one - " How do I filter for that?

$SearchString = str_replace(""", '', $SearchString); that's not going to work.