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<?php $strings = ["folders/folder1/folder5/../../folder2", "folders/folder1/../../../folder2", "folders/folder1/folder5/../folder2"]; foreach ($strings as $url) { $count = 0; do { $url = preg_replace('~(?<![^/])(?!\.\.(?![^/]))[^/]+/\.\.(?:/|$)~', '', $url, -1, $count); } while ($count > 0); echo "$url" . PHP_EOL; }
Finding entry points
Branch analysis from position: 0
2 jumps found. (Code = 77) Position 1 = 2, Position 2 = 18
Branch analysis from position: 2
2 jumps found. (Code = 78) Position 1 = 3, Position 2 = 18
Branch analysis from position: 3
2 jumps found. (Code = 44) Position 1 = 14, Position 2 = 4
Branch analysis from position: 14
1 jumps found. (Code = 42) Position 1 = 2
Branch analysis from position: 2
Branch analysis from position: 4
Branch analysis from position: 18
1 jumps found. (Code = 62) Position 1 = -2
Branch analysis from position: 18
filename:       /in/ZZboE
function name:  (null)
number of ops:  20
compiled vars:  !0 = $strings, !1 = $url, !2 = $count
line      #* E I O op                               fetch          ext  return  operands
-----------------------------------------------------------------------------------------
    3     0  E >   ASSIGN                                                       !0, <array>
    4     1      > FE_RESET_R                                           $4      !0, ->18
          2    > > FE_FETCH_R                                                   $4, !1, ->18
    5     3    >   ASSIGN                                                       !2, 0
    7     4    >   INIT_FCALL                                                   'preg_replace'
          5        SEND_VAL                                                     '%7E%28%3F%3C%21%5B%5E%2F%5D%29%28%3F%21%5C.%5C.%28%3F%21%5B%5E%2F%5D%29%29%5B%5E%2F%5D%2B%2F%5C.%5C.%28%3F%3A%2F%7C%24%29%7E'
          6        SEND_VAL                                                     ''
          7        SEND_VAR                                                     !1
          8        SEND_VAL                                                     -1
          9        SEND_REF                                                     !2
         10        DO_ICALL                                             $6      
         11        ASSIGN                                                       !1, $6
    8    12        IS_SMALLER                                                   0, !2
         13      > JMPNZ                                                        ~8, ->4
    9    14    >   CAST                                              6  ~9      !1
         15        CONCAT                                               ~10     ~9, '%0A'
         16        ECHO                                                         ~10
    4    17      > JMP                                                          ->2
         18    >   FE_FREE                                                      $4
   10    19      > RETURN                                                       1

Generated using Vulcan Logic Dumper, using php 8.5.0


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158.51 ms | 1993 KiB | 14 Q