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<?php echo "PHP:\n"; // echo "1: \", "\n"; - syntax error echo "2: \\", "\n"; // outputs \ // echo "3: \\\", "\n"; - syntax error echo "4: \\\\", "\n"; // outputs \\ // echo "5: \\\\\", "\n"; - syntax error echo "6: \\\\\\", "\n"; // outputs \\\ // echo "7: \\\\\\\", "\n"; - syntax error echo "8: \\\\\\\\", "\n"; // outputs \\\\ echo "\nPHP + PCRE:\n"; // skipping odd counts because they're all syntax errors echo "2: ", preg_replace('/^/', '\\', ""), "\n"; // PCRE receives \ and allows it as a lone \ -> output \ echo "4: ", preg_replace('/^/', '\\\\', ""), "\n"; // PCRE receives \\ and interprets it as \ -> output \ echo "6: ", preg_replace('/^/', '\\\\\\', ""), "\n"; // PCRE receives \\\ and interprets it as \ + lone \ -> output \\ echo "8: ", preg_replace('/^/', '\\\\\\\\', ""), "\n"; // PCRE receives \\\\ and interprets it as \\ -> output \\
Finding entry points
Branch analysis from position: 0
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/Sjn85
function name:  (null)
number of ops:  43
compiled vars:  none
line      #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
    3     0  E >   ECHO                                                     'PHP%3A%0A'
    5     1        ECHO                                                     '2%3A+%5C'
          2        ECHO                                                     '%0A'
    7     3        ECHO                                                     '4%3A+%5C%5C'
          4        ECHO                                                     '%0A'
    9     5        ECHO                                                     '6%3A+%5C%5C%5C'
          6        ECHO                                                     '%0A'
   11     7        ECHO                                                     '8%3A+%5C%5C%5C%5C'
          8        ECHO                                                     '%0A'
   13     9        ECHO                                                     '%0APHP+%2B+PCRE%3A%0A'
   15    10        ECHO                                                     '2%3A+'
         11        INIT_FCALL                                               'preg_replace'
         12        SEND_VAL                                                 '%2F%5E%2F'
         13        SEND_VAL                                                 '%5C'
         14        SEND_VAL                                                 ''
         15        DO_ICALL                                         $0      
         16        ECHO                                                     $0
         17        ECHO                                                     '%0A'
   16    18        ECHO                                                     '4%3A+'
         19        INIT_FCALL                                               'preg_replace'
         20        SEND_VAL                                                 '%2F%5E%2F'
         21        SEND_VAL                                                 '%5C%5C'
         22        SEND_VAL                                                 ''
         23        DO_ICALL                                         $1      
         24        ECHO                                                     $1
         25        ECHO                                                     '%0A'
   17    26        ECHO                                                     '6%3A+'
         27        INIT_FCALL                                               'preg_replace'
         28        SEND_VAL                                                 '%2F%5E%2F'
         29        SEND_VAL                                                 '%5C%5C%5C'
         30        SEND_VAL                                                 ''
         31        DO_ICALL                                         $2      
         32        ECHO                                                     $2
         33        ECHO                                                     '%0A'
   18    34        ECHO                                                     '8%3A+'
         35        INIT_FCALL                                               'preg_replace'
         36        SEND_VAL                                                 '%2F%5E%2F'
         37        SEND_VAL                                                 '%5C%5C%5C%5C'
         38        SEND_VAL                                                 ''
         39        DO_ICALL                                         $3      
         40        ECHO                                                     $3
         41        ECHO                                                     '%0A'
         42      > RETURN                                                   1

Generated using Vulcan Logic Dumper, using php 8.0.0


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