(PHP 4 >= 4.3.0, PHP 5)
mb_regex_set_options — Set/Get the default options for mbregex functions
$options = mb_regex_set_options()
  ] )
   Sets the default options described by options 
   for multibyte regex functions.
  
optionsThe options to set. This is a string where each character is an option. To set a mode, the mode character must be the last one set, however there can only be set one mode but multiple options.
| Option | Meaning | 
|---|---|
| i | Ambiguity match on | 
| x | Enables extended pattern form | 
| m | '.' matches with newlines | 
| s | '^' -> '\A', '$' -> '\Z' | 
| p | Same as both the m and s options | 
| l | Finds longest matches | 
| n | Ignores empty matches | 
| e | eval() resulting code | 
| Mode | Meaning | 
|---|---|
| j | Java (Sun java.util.regex) | 
| u | GNU regex | 
| g | grep | 
| c | Emacs | 
| r | Ruby | 
| z | Perl | 
| b | POSIX Basic regex | 
| d | POSIX Extended regex | 
   The previous options. If options is omitted, 
   it returns the string that describes the current options.