Regular expression - Unknown modifier '(' in

Question

I had this regular expression:

preg_match("|[\|()<>%*+=]|(=)+(!)|[-]{2}|", $status, $array);

that generates this warning

Warning: preg_match(): Unknown modifier '(' in...

I know that is a problem of \ but I don't know where to put them.

Read [PCRE regex syntax: Delimiters](http://php.net/regexp.reference.delimiters). — Gumbo, Dec 01 '13 at 18:53

score 1 · Answer 1 · answered Dec 01 '13 at 18:54

The problem is that you are using | as the delimiter for the pattern, so the second | ends the pattern and the ( is interpreted as a modifier. Do one of these, depending on if you need the | at the beginning and end:

preg_match("/|[\|()<>%*+=]|(=)+(!)|[-]{2}|/", $status, $array);
preg_match("/[\|()<>%*+=]|(=)+(!)|[-]{2}/", $status, $array);

score 0 · Answer 2 · answered Dec 01 '13 at 18:55

0

The is some problems... Let see:

Yours:

  "|[\|()<>%*+=]|(=)+(!)|[-]{2}|"
   ^ first problem not needed as is an OR and there is nothing before it
       ^ you have to scape the parentesis all of it
            ^ you have to scape the asterisk
                               ^unecessary there is nothing after

So the result would be:

  "/[\|\(\)<>%\*+=]|(=)+(!)|[-]{2}/"

answered Dec 01 '13 at 18:55

Jorge Campos

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Thank you very much, I used your regular expression ;) – Dec 01 '13 at 20:02

Regular expression - Unknown modifier '(' in

2 Answers2