PHP regular expressions

[Anon]

How would I ensure that a variable may only contain alphabetical characters, apostrophes or hyphens?

[baruch]

If you want only to verify that it doesn't contain anything else you don't need a regex, use strspn as follows:
// Fill the allowedchars variable
$allowedchars = "01234567890abcABC"
if (strspn($str, $allowedchars) == strlen($str)) {
print('All is ok.');
} else {
print('string contains invalid characters');
}

if you want to replace the invalid chars with nothing (remove them):
preg_replace("[^{$allowedchars]",} '', $str)

[Anon]

My two cents....

<?
/
if spaces aren't allowed either,
then remove the [:space:]
part of the regex
*/

function checkFormat($var)
{
if(eregi("[^{/'a-zA-Z[:space:]/-]",} $var))
return false;
return true;
}

$text1="Tom's Car - Late Model Buick";
$text2="Fred's Car - '66 Cadillac";

checkFormat($text1)?print"Good":print"Bad";
print"<br>";
checkFormat($text2)?print"Good":print"Bad";
?>