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<?php $string = 'start ** not bold ** and **bold** not bold **bold *** still bold** not bold **** not bold ****'; echo preg_replace('/(?<!\*)\*\*(?![\s*])(.*?)(?<![\s*])\*\*(?!\*)/', '<b>$1</b>', $string);
Finding entry points
Branch analysis from position: 0
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/HRquk
function name:  (null)
number of ops:  5
compiled vars:  !0 = $string
line      #* E I O op                               fetch          ext  return  operands
-----------------------------------------------------------------------------------------
    3     0  E >   ASSIGN                                                       !0, 'start+%2A%2A+not+bold+%2A%2A+and+%2A%2Abold%2A%2A+not+bold+%2A%2Abold+%2A%2A%2A+still+bold%2A%2A+not+bold+%2A%2A%2A%2A+not+bold+%2A%2A%2A%2A'
    5     1        FRAMELESS_ICALL_3                preg_replace        ~2      '%2F%28%3F%3C%21%5C%2A%29%5C%2A%5C%2A%28%3F%21%5B%5Cs%2A%5D%29%28.%2A%3F%29%28%3F%3C%21%5B%5Cs%2A%5D%29%5C%2A%5C%2A%28%3F%21%5C%2A%29%2F', '%3Cb%3E%241%3C%2Fb%3E'
          2        OP_DATA                                                      !0
          3        ECHO                                                         ~2
          4      > RETURN                                                       1

Generated using Vulcan Logic Dumper, using php 8.5.0


preferences:
212.77 ms | 2007 KiB | 13 Q