CODEWITHSUNDEEP
phpregex
Shoaulin
Shoaulin

Reputation: 127

Can't use certain characters in a regex

if(!eregi("^([0-9a-z_\[\]\*\- ])+$", $subuser))
    $form->setError($field, "* Username not alphanumeric");

Can anybody tell me why it is not allowing characters such as - and *?

if(!eregi("^([0-9a-z])+$", $subuser))
    $form->setError($field, "* Username not alphanumeric");

That is the original piece of code. A friend changed it to the top piece and it will allow a-z and 0-9 but it wont allow the other characters I need it to. Can anyone help me?

Thanks in advance.

Upvotes: 1

Views: 509

Answers (4)

Trent
Trent

Reputation: 56

For bracket expressions:

To include a literal ] in the list, make it the first character (following a possible ^). To include a literal -, make it the first or last character, or the second endpoint of a range. To use a literal - as the first endpoint of a range, enclose it in [. and .] to make it a collating element (see below). With the exception of these and some combinations using [ (see next paragraphs), all other special characters, including \, lose their special significance within a bracket expression.

So this should do what you want:

"^([]0-9a-z_[* -])+$"

Upvotes: 4

Peter Bailey
Peter Bailey

Reputation: 105888

Don't use the ereg family of functions - they are slower and, if I recall correctly, will eventually be deprecated.

This should fix it

if ( preg_match( "/^[^0-9a-z_\[\]* -]$/i", $subuser )
{
    $form->setError( $field, "* Username not alphanumeric" );
}

Upvotes: 3

mike
mike

Reputation:

even using preg_* functions the pattern needs to be wrapped in nonalphanum delimiters:

"~^([0-9a-z_[]*- ])+$~"

Upvotes: 1

Henning
Henning

Reputation: 11696

Your regex uses PCRE syntax, so you have to use preg_match() instead of eregi().

Try this code instead:

else if (!preg_match("/^([0-9a-z_\[\]* -])+$/i", $subuser)) {
$form->setError($field, "* Username not alphanumeric");
}

Upvotes: 7

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