> If the pattern delimiter character appears in the pattern it must be
> escaped so that the regexp processor will correctly interpret it as a
> pattern character and not as the end of the pattern.
>
> This would produce a regexp error:
>
> /ldap://*/
>
> but this is OK:
>
> /ldap:\/\/*/
>
> Therefore if you choose another delimiter altogether you don't have
> to escape the slashes:
>
> #ldap://*#
>
> Cleaner and more clear.

Ok, that makes sense.

> >preg_match('|^ldap(s)?://[a-zA-Z0-9-]+\.[a-zA-Z.]{2,5}$|', $this->server
)
> >>
> >>I also recommend using single quotes instead of double quotes here.
> >
> >Single Quotes: Noted. Any reason why? I guess you might be a little out
of
> >luck putting $vars into a regex without . concatenating.
>
> Both PHP and regexp use the backslash as an escape. Inside double
> quotes, PHP interprets \ as escape, while inside single quotes PHP
> interprets \ as a simple backslash character.
>
> When working with regexp in PHP you're dealing with two interpreters,
> first PHP and then regexp. To support PHP's interpretation with
> double quotes, you have to escape the escapes:
>
> Single quotes: '/ldap:\/\/*/'
> Double quotes: "/ldap:\\/\\/*/"
>
> PHP interprets "\\/" as \/
> RegExp interprets \/ as /

Oh. Duh! I wasn't even considering PHP parsing the string due to the double
quoted string.

> So, for a pattern like this that contains slashes, it's best to use a
> non-slash delimiter AND single quotes (unless, as you say, you need
> to include PHP variables in the pattern):
>
> $pattern = '#ldap://*#';
>
> Personally I favor heredoc syntax for such situations because I don't
> have to worry about the quotes:
>
> $regexp = <<<_
> #ldap://*$var#
> _;

Yeah, I just wish there were some way heredoc could work on one line.

> >>why is there a period in the second pattern?
> >
> >The period comes from the original article on SitePoint (linked earlier).
Is
> >it unnecessary? I can't say I'm real sure what this means for the '.' in
> >regex's:
> >
> >"Matches any single character except line break characters \r and \n.
Most
> >regex flavors have an option to make the dot match line break characters
> >too."
> >- http://www.regular-expressions.info/reference.html
>
> Inside of a bracketed character class, the dot means a literal period
> character and not a wildcard.
>
> "All non-alphanumeric characters other than \, -, ^ (at the start)
> and the terminating ] are non-special in character classes"

So what does the definition I posted mean for non-bracketed periods? Does it
mean it will match anything but a line or return break character? How in
practice is this useful?

> PHP PREG
> Pattern Syntax
> http://www.php.net/manual/en/referen...ern.syntax.php
> scroll down to 'Square brackets'
>
>
> >>Also, why are you allowing for uppercase letters
> >>when the RFC's don't allow them?
> >
> >I hadn't gotten far enough to strtolower(), but that's a good point, I
> >hadn't actually considered it yet.
>
> Perhaps it has to do with the source of the string: can you guarantee
> that the URIs passed to this routine conform to spec?

I just prefer to use strtolower(). I have to use the server address
anyways...

Breaking News: I had a thought (surprise!). Are LDAP servers ever on
localhost? Or at least a non-dot-concatenated address
(ldap://directoryname)? The pattern we've been looking won't match that, I
think.

> Another way to handle this would be to simply accept case-insensitive
strings:
>
> |^ldap(s)?://[a-z0-9-]+\.[a-z.]{2,5}$|i

I actually read about that a little while ago, I just didn't know where to
put the i. Thanks!

> Pattern Modifiers
> http://www.php.net/manual/en/referen....modifiers.php
>
> "i (PCRE_CASELESS)
> " If this modifier is set, letters in the pattern match both upper
> and lower case letters."

How do you test regex's against any known variants? I suppose I need to
build a test function to make arbitrary strings and then test and print the
results. I just don't know if my regex is going to be that great in
practice.

This would be in addition to the program Richard alluded to in the code
checker.

Thanks!

--
Jared Farrish
Intermediate Web Developer
Denton, Tx

Abraham Maslow: "If the only tool you have is a hammer, you tend to see
every problem as a nail." $$