Regular Expression matching character-PHP source code

Ec (2); regular expression matching rules are modified as follows :([. n] *), of course, if it is written directly in a java program, you need to change it ([. n] *) the result is that the program is run again and NO content can be obtained. I was puzzled, and changed it to the following rules: ([. | n] *) and ([n.] *) the result is still not good, and nothing can be obtained. It seems that the dot and line break are busy ~ Then I checked the Internet. Although I didn't find out what the above rule was, I found a script ec (2); script

Modify the regular expression matching rules as follows:
([. N] *). Of course, if it is written directly in a java program, you need to change it to ([. n] *)
The result is that the program is run again and NO content can be obtained. I was puzzled and changed it to the following rules:
([. | N] *) and ([n.] *)
The result still does not work, and nothing can be obtained. It seems that the dot and line break are busy ~
Then I checked the Internet. Although I didn't find out what the above rule was, I found a solution. After a try, I could indeed match any character including line breaks, the following are the correct Regular Expression matching rules:
([Ss] *)
You can also use "([dd] *)" and "([ww.

In a text file, this expression can match all English letters.
/[-~] /
This expression can match all non-English characters (such as Chinese)
/[^-~] /
/Is Used in vi. You do not need it in editplus or program/

$ Pattern = "/d /";
If (preg_match ($ pattern, $ str, $ output )){
Echo "matched characters". $ output;
}
Else echo "failed to match characters ";
?>