Special characters in regular expression

[jaddy]

Hi everybody,

What are exactly the special characters that need to be escaped in the regular expression string???

And is escaping characters in all the systems work in the same way?

Thx.

[dar-k]

http://www.google.com/search?q=php+regular+expression+special+characters

I'm not sure about ur second question.

[abnfire]

escape this chars:
[
]
.
*
+
?
{
}
(
)
$
^
/
and may be more...

second question:
so far i know, yes they work same on other OS.

[Weedpacket]

If you're using preg_* functions for regular expressions (and it would be a good idea), you can use [man]preg_quote[/man] to quote all PCRE metacharacters in a string.

[jaddy]

Thx,

While I am trying this:

$n = eregi_replace("[?()+*=#$|{}\"\\\'\\\\\\\/]","",$n);

I noticed the followings:

These characters need to be escaped:
" ' \ /

While these I didn't escape them and my code works fine:
? ) ( + * = # $ | { }

These characters I didn't test them yet, but they seems not to be escaped:
_ - . , : ; ! @ % &

I don't know anything about these characters:
] [ ~ ` ^ < >

Is there is a rule or something??

thx