(command.CommandList
  children: [
    (command.If
      arms: [
        (if_arm
          cond: 
            (condition.Shell
              commands: [
                (command.Sentence
                  child: 
                    (C {<Id.Lit_LBracket '['>} {(DQ ($ Id.VSub_DollarName SSH_CLIENT))} 
                      {<Id.Lit_RBracket ']'>}
                    )
                  terminator: <Id.Op_Semi _>
                )
              ]
            )
          action: [
            (command.ShAssignment
              pairs: [
                (assign_pair
                  lhs: (sh_lhs_expr.Name left:<Id.Lit_VarLike 'expression='> name:expression)
                  op: assign_op.Equal
                  rhs: 
                    {
                      (command_sub
                        left_token: <Id.Left_DollarParen '$('>
                        child: 
                          (command.Pipeline
                            children: [
                              (C {<echo>} {(DQ ($ Id.VSub_DollarName SSH_CLIENT))})
                              (C {<sed>} 
                                {
                                  (SQ <'s/.*://;\n'> 
                                    <
'         s/^\\([0-9.]*\\) [0-9]* \\([0-9]*\\)$/not \\( host \\1 and port \\2 \\)/'
                                    >
                                  )
                                }
                              )
                            ]
                            negated: F
                            stderr_indices: []
                          )
                        right: <Id.Eof_RParen _>
                      )
                    }
                  spids: [59]
                )
              ]
              redirects: []
            )
          ]
          spids: [45 56]
        )
      ]
      else_action: []
      redirects: []
    )
    (C {<tcpdump>} {(DQ ($ Id.VSub_At '@'))} {($ Id.VSub_DollarName expression)})
  ]
)