Regular Expression Problem

intermediate

I'm using regular expressions to allow users on a message board to type certain commands to do different things for example they type /msg username message in order to private message a user.

when i try to use regular expressions to set up the variables i need the variable for message to be anything.

/msg coolguy hello wuts up! =)

$message = eregi_replace("(/msg) ([_a-zA-Z0-9-]+) ()", "\3", $string);

variable \2 is the username they are sending the private message to, but i want variable //3 to not have any criteria to meet, so it can be any character in the entire world, no restrictions. like username is restricted to letters, numbers, underscores and dashes. how do i create the variable \3 correctly because it doesn't work that way.

please help! thnx!

intermediate

help plz

matt_4013

Hi there, if I was you, I'd use a PCRE for this:

$message = preg_replace("!(/msg) ([a-z0-9\\\\-]+)(.+?)!si", "\\\\3", $string);

The expression is saying this:
! is the start of the expression
(/msg) 1 instance of /msg
([a-z0-9\-]+) 1 or more alphanumeric characters, or a -
(.+?) 1 or more of ANY character
!si End of expression, s to span multiple lines, i for case insensitive 🙂

Hope that helps,
Matt

intermediate

i get the same problem as before... for some reason the variable \2 includes both the first and second parenthesis

so for example if i type in /msg username hello

the variable \2 = usernamehello

and i only want it to be username

matt_4013

Copy paste this, i missed a space in the last one.

$message = preg_replace("!(/msg) ([a-z0-9\\\\-]+) (.+?)!si", "\\\\3", $string);

I know it works, because I tested it. I changed it to this:

$message = preg_replace("!(/msg) ([a-z0-9\\\\-]+) (.+?)!si", "\\\\2:\\\\3", $string);

Input was /msg username blah blah

And my output of $message was:

username:blah blah

intermediate

same problem.. =\

matt_4013

Can you post your code? This regex works fine for me on a simple script, there must be something else in there.

intermediate

your code works fine when i just use:

print (preg_replace("!(/msg) ([a-z0-9\-]+) (.+?)!si", "\2:\3", $_POST["message"]));

the output prints the variables fine... but i want to use 2 seperate variables to represent the username and the message. i used this:

$eregusername = preg_replace("!(/msg) ([a-z0-9\-]+) (.+?)!si", "\2", $_POST["message"]);

$eregmessage = preg_replace("!(/msg) ([a-z0-9\-]+) (.+?)!si", "\3", $_POST["message"]);

for some reason the variable $eregusername's output is messed up

for example: when i put "/msg user message" in the form and then i print both of the variables $eregusername and $eregmessage i get "message" for $eregmessage but then i get "useressage" for $eregusername.

matt_4013

Yick, don't use 2 preg_replace's for that, it's REALLY inefficient. What you should use is a preg_match. That will put your output into an array, and you can access the variables from there. It's much faster.

preg_match("!^.*/msg ([a-z0-9\\\\-]+) (.+)$!si", $_POST['text'], $message);

This will create $message as an array, with 3 elements. The first will be your original string, the 2nd will be the username and the 3rd will be your message.

BTW, I would suggest you read this: http://www.phpbuilder.com/board/showthread.php?s=&threadid=10218925
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