[clantron]

PHP Code:

function openpage(){

        return "<a href='http://www.google.com' target='_blank' onClick=\"".popup("http://www.google.com").";return false;\">test</a>";

}

function popup($page){

        return "window.open('$page','".preg_replace("([^[:alnum:]])","",$page)."','scrollbars=no,resizable=no,width=300,height=300')";

} 

Now I understand most of this.
But what exactly does preg_replace replace here?
I know a nice rule, if it aint broken dont fix it, but I'm just wondering what it does? So I can understand what is going on.

Used google in testing so I could see if it worked and it does to my suprise.
again .. following part is where I'm lost:
return "window.open('$page','".preg_replace("([^[:alnum:]])","",$page)."','scrollbars=no,resizable=no,width=300,height=300' )";

Also, everything works there is no bug. I'm just hungry for knowledge

[nekeno12]

This particular regex replaces any characters NOT equal to '[:alnum:]'. Don't ask me why the regex is looking for that particular string, but there's your answer.

[clantron]

hmm again this regex thing..
came across it about 5 min ago in another thing.
*starts googling and php manual-ing*

Thanks for the explanation

[End User]

Here's a quick RegExp tutorial.

Modifiers
i case-insensitive pattern matching.
g global replace, or replace all
m Treat string as multiple lines. That is, change ``^'' and ``$'' from matching at only the very start or end of the string to the start or end of any line anywhere within the string
s Treat string as single line. That is, change ``.'' to match any character whatsoever, even a newline, which it normally would not match.
x Extend your pattern's legibility by permitting whitespace and comments.

Special Characters
The following should be escaped if you are trying to match that character

\ ^ . $ | ( ) [ ]
* + ? { } ,

Special Character Definitions
\ Quote the next metacharacter
^ Match the beginning of the line
. Match any character (except newline)
$ Match the end of the line (or before newline at the end)
| Alternation
() Grouping
[] Character class
* Match 0 or more times
+ Match 1 or more times
? Match 1 or 0 times
{n} Match exactly n times
{n,} Match at least n times
{n,m} Match at least n but not more than m times
More Special Character Stuff
\t tab (HT, TAB)
\n newline (LF, NL)
\r return (CR)
\f form feed (FF)
\a alarm (bell) (BEL)
\e escape (think troff) (ESC)
\033 octal char (think of a PDP-11)
\x1B hex char
\c[ control char
\l lowercase next char (think vi)
\u uppercase next char (think vi)
\L lowercase till \E (think vi)
\U uppercase till \E (think vi)
\E end case modification (think vi)
\Q quote (disable) pattern metacharacters till \E
Even More Special Characters
\w Match a "word" character (alphanumeric plus "_")
\W Match a non-word character
\s Match a whitespace character
\S Match a non-whitespace character
\d Match a digit character
\D Match a non-digit character
\b Match a word boundary
\B Match a non-(word boundary)
\A Match only at beginning of string
\Z Match only at end of string, or before newline at the end
\z Match only at end of string
\G Match only where previous m//g left off (works only with /g)

[clantron]

thx man
copied it into a txt file for future reference