从字符串中获取所需的子字符串

How do I get substring from string which start with s and end with /s.

$text can be in following formats

 $text = "LowsABC/s";
 $text = "sABC/sLow";
 $text = "ABC";

how can I get ABC, sometime it may happen that $text does not contain s and /s just only ABC, Still I want to get the ABC.

The regular expression:

s(.*)/s

Or when you want to get a string of minimal length:

s(.*?)/s

And apply this res you can using preg_match:

preg_match( '@s(.*)/s@', $text, $match );
var_dump( $match );

And now you must check, if something was found or not, and if not, then the result must be set to the entire string:

if (not $match) {
   $match = $text;
}

Example of usage:

$ cat 1.php 
<?
$text = "LowsABC/s";
preg_match( '@s(.*)/s@', $text, $match );
var_dump( $match );
?>

$ php 1.php
array(2) {
  [0]=>
  string(6) "sABC/s"
  [1]=>
  string(3) "ABC"
}

Might be trivial, but what about just using something like this (Regexs aren't always worth the trouble ;) ):

$text = (strpos($text,'s') !== false and strpos($text,'/s') !== false) ? preg_replace('/^.*s(.+)\/s.*$/','$1',$text) : $text;