pcre expression for irc nicknames?

Hey guys, I'm having a few issues with using PCRE to make a irc nickname format correctly. I'm not good with PCRE, and I'd love some suggestions from those of you who do use PCRE / regex. :)

I'm currently using this expression: /^([^A-Za-z]{1})([^A-Za-z0-9-.]{0,32})$/ I'm using it as such: preg_replace($regex, $replaceWith, $content)

开发者_Python百科

I assumed this meant, starting from the front to the end, any characters that are not A-Z, a-z, or 0-9 for the first character, replace it. Any characters after that, in which are not A-Z a-z, 0-9, -, or ., replace it.

If anyone could help, you would be helping out greatly. It's the only thing stopping me from releasing a chat product to a new forum software. :/

---

I've been using the following regex to check for nicknames in my IRC logs:

/<([a-zA-Z\[\]\\`_\^\{\|\}][a-zA-Z0-9\[\]\\`_\^\{\|\}-]{1,31})>/

using it in a preg_match like so:

preg_match('/<([a-zA-Z\[\]\\`_\^\{\|\}][a-zA-Z0-9\[\]\\`_\^\{\|\}-]{1,31})>/', $line)

I simply check whether a user said something on the line and the line wasn't just a join/part message or nick change or something of the sort, but it would be easy to put it into a preg_replace too.

It matches the nicks according to the nickname rules in RFC 2812 Section 2.3.1, which state that the first character must be a letter (a-zA-Z) or special ([]{}^`|_\) and the rest of the characters may be letters, special, digits (0-9) or hyphens (-). I chose the max length of 32 based on GTAnet's NICKLEN=32 instead of the RFC's max length of 9, because many networks don't seem to follow this standard. The max length varies between different IRC networks so tweak it as required.

---

I'm not sure what you're trying to replace with, but it'd be better to check if the string matches a username (instead of not matching) and then replace if it doesn't:

$regex = '/^[a-z][a-z0-9.-]{0,32}$/i';
if (!preg_match($regex, $content))
{
  // do your replace here
}

The regular expression says:

^                   # Beginning of string
  [a-z]             # Match a single a-z
  [a-z0-9.-]{0,32}  # Match between 0 and 32 occurances of a-z, 0-9, . or -
$                   # End of string
/i                  # Make the pattern case-insensitive