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<?php $char_set = 'a-z_'; $val = 'login_form'; $val = preg_replace('/[^'.preg_quote($char_set, '/').']+/i', '', $val); var_dump($val);
Finding entry points
Branch analysis from position: 0
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/eOIHj
function name:  (null)
number of ops:  18
compiled vars:  !0 = $char_set, !1 = $val
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
    3     0  E >   ASSIGN                                                   !0, 'a-z_'
    4     1        ASSIGN                                                   !1, 'login_form'
    5     2        INIT_FCALL                                               'preg_replace'
          3        INIT_FCALL                                               'preg_quote'
          4        SEND_VAR                                                 !0
          5        SEND_VAL                                                 '%2F'
          6        DO_ICALL                                         $4      
          7        CONCAT                                           ~5      '%2F%5B%5E', $4
          8        CONCAT                                           ~6      ~5, '%5D%2B%2Fi'
          9        SEND_VAL                                                 ~6
         10        SEND_VAL                                                 ''
         11        SEND_VAR                                                 !1
         12        DO_ICALL                                         $7      
         13        ASSIGN                                                   !1, $7
    6    14        INIT_FCALL                                               'var_dump'
         15        SEND_VAR                                                 !1
         16        DO_ICALL                                                 
         17      > RETURN                                                   1

Generated using Vulcan Logic Dumper, using php 8.0.0


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