I try to match this expression :
* ^X-Spam-Flag: YES
I use this code :
if(preg_match('\'* ^X-Spam-Flag: YES\'', $value))
But i have this error :
PHP Warning: preg_match(): Compilation failed: nothing to repeat at offset 0
Problem with regex and * and ^ but can i correct that ?
You are missing your delimiters.
Change to:
preg_match('#\'* ^X-Spam-Flag: YES\'#', $value)
Or maybe you need:
preg_match('#\* \^X-Spam-Flag: YES#', $value)
You was near the solution, you have to escape ^ and * since these have a special meaning in a regex pattern:
if(preg_match('\'\* \^X-Spam-Flag: YES\'', $value))
If your escaped single quotes look strange and may be better replaced by / or ~ ... however these can be used as delimiters.
More informations about delimiters here: http://www.php.net/manual/en/regexp.reference.delimiters.php
To safely escape Regex special characters, you can simply use "preg_quote()", which adds backslashes in front of these characters.
if(preg_match('\'* ^X-Spam-Flag: YES\'', preg_quote($value)))