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<?php // 获取user参数的值(如果为空,则用'nobody') $username = @$_GET['user'] ?: 'nobody'; // 等价于: $username = isset($_GET['user']) ? $_GET['user'] : 'nobody'; echo $username;
based on q8gPN
Finding entry points
Branch analysis from position: 0
2 jumps found. (Code = 43) Position 1 = 10, Position 2 = 14
Branch analysis from position: 10
1 jumps found. (Code = 42) Position 1 = 15
Branch analysis from position: 15
1 jumps found. (Code = 62) Position 1 = -2
Branch analysis from position: 14
1 jumps found. (Code = 62) Position 1 = -2
filename:       /in/aDUW8
function name:  (null)
number of ops:  18
compiled vars:  !0 = $username
line     #* E I O op                           fetch          ext  return  operands
-------------------------------------------------------------------------------------
   4     0  E >   BEGIN_SILENCE                                    ~1      
         1        FETCH_R                      global              ~2      '_GET'
         2        FETCH_DIM_R                                      ~3      ~2, 'user'
         3        END_SILENCE                                              ~1
         4        JMP_SET                                          ~4      ~3, ->6
         5        ASSIGN_BW_OR                                  0  ~4      'nobody'
         6        QM_ASSIGN                                                !0
   6     7        FETCH_IS                                         ~6      '_GET'
         8        ISSET_ISEMPTY_DIM_OBJ                         0  ~7      ~6, 'user'
         9      > JMPZ                                                     ~7, ->14
        10    >   FETCH_R                      global              ~8      '_GET'
        11        FETCH_DIM_R                                      ~9      ~8, 'user'
        12        ASSIGN_BW_OR                                  0  ~10     ~9
        13      > JMP                                                      ->15
        14    >   ASSIGN_BW_OR                                  0  ~10     'nobody'
        15    >   QM_ASSIGN                                                !0
   8    16        ASSIGN_OBJ                                               !0
        17      > RETURN                                                   1

Generated using Vulcan Logic Dumper, using php 7.4.0