(command.CommandList
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    (command.ShAssignment
      pairs: [(assign_pair lhs:(sh_lhs_expr.Name name:file) op:Equal rhs:{(DQ ($ VSub_Number '$1'))})]
    )
    (command.ShAssignment
      pairs: [(assign_pair lhs:(sh_lhs_expr.Name name:epoch) op:Equal rhs:{(DQ ($ VSub_Number '$2'))})]
    )
    (command.If
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        (if_arm
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            (command.Sentence
              child: 
                (command.AndOr
                  ops: [Op_DPipe]
                  children: [
                    (C {(Lit_LBracket '[')} {(KW_Bang '!')} {(-f)} {(DQ ($ VSub_DollarName '$file'))} 
                      {(Lit_RBracket ']')}
                    )
                    (C {(Lit_LBracket '[')} {($ VSub_Pound '$#')} {(-ne)} {(1)} {(-a)} 
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                    )
                  ]
                )
              terminator: <Op_Semi ';'>
            )
          ]
          action: [
            (command.Simple
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                {(echo)}
                {
                  (DQ ('Usage: ') 
                    (command_sub
                      left_token: <Left_Backtick '`'>
                      command_list: 
                        (command.CommandList
                          children: [(C {(basename)} {($ VSub_Number '$0')})]
                        )
                    ) (' file [epoch]')
                  )
                }
              ]
              redirects: [(redir.Redir op:<Redir_GreatAnd '>&'> fd:16777215 arg_word:{(2)})]
            )
            (command.ControlFlow token:<ControlFlow_Exit exit> arg_word:{(1)})
          ]
        )
      ]
    )
    (command.If
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        (if_arm
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            (command.Sentence
              child: 
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                )
              terminator: <Op_Semi ';'>
            )
          ]
          action: [
            (command.AndOr
              ops: [Op_DPipe]
              children: [
                (command.ShAssignment
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                    (assign_pair
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                      op: Equal
                      rhs: 
                        {
                          (command_sub
                            left_token: <Left_Backtick '`'>
                            command_list: 
                              (command.CommandList
                                children: [
                                  (C {(date)} 
                                    {(--reference) (Lit_Equals '=') (DQ ($ VSub_DollarName '$file'))} {(Lit_Other '+') (Lit_Other '%') (s.) (Lit_Other '%') (N)}
                                  )
                                ]
                              )
                          )
                        }
                    )
                  ]
                )
                (command.ControlFlow token:<ControlFlow_Exit exit> arg_word:{(1)})
              ]
            )
          ]
        )
      ]
      else_action: [
        (command.If
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            (if_arm
              cond: [
                (command.Sentence
                  child: 
                    (command.Pipeline
                      children: [
                        (C {(echo)} {(DQ ($ VSub_DollarName '$epoch'))})
                        (C {(grep)} {(-Eq)} {(DQ ('^[') (Lit_Other '\\') ('+-]'))})
                      ]
                      negated: F
                    )
                  terminator: <Op_Semi ';'>
                )
              ]
              action: [
                (command.Simple
                  words: [{(echo)} {(DQ ('Epochs with leading +/- are ambiguous with editor options'))}]
                  redirects: [(redir.Redir op:<Redir_GreatAnd '>&'> fd:16777215 arg_word:{(2)})]
                )
                (command.ControlFlow token:<ControlFlow_Exit exit> arg_word:{(1)})
              ]
            )
          ]
        )
        (command.If
          arms: [
            (if_arm
              cond: [
                (command.Sentence
                  child: 
                    (command.Pipeline
                      children: [
                        (command.Simple
                          words: [
                            {(date)}
                            {(--date) (Lit_Equals '=') 
                              (DQ ('1970-01-01 UTC ') ($ VSub_DollarName '$epoch') (' seconds'))
                            }
                          ]
                          redirects: [
                            (redir.Redir
                              op: <Redir_Great '>'>
                              fd: 16777215
                              arg_word: {(/dev/null)}
                            )
                            (redir.Redir
                              op: <Redir_GreatAnd '2>&'>
                              fd: 2
                              arg_word: {(1)}
                            )
                          ]
                        )
                      ]
                      negated: T
                    )
                  terminator: <Op_Semi ';'>
                )
              ]
              action: [
                (command.Simple
                  words: [
                    {(echo)}
                    {(DQ ('Invalid epoch specified [') ($ VSub_DollarName '$epoch') (']'))}
                  ]
                  redirects: [(redir.Redir op:<Redir_GreatAnd '>&'> fd:16777215 arg_word:{(2)})]
                )
                (command.ControlFlow token:<ControlFlow_Exit exit> arg_word:{(1)})
              ]
            )
          ]
        )
      ]
    )
    (command.If
      arms: [
        (if_arm
          cond: [
            (command.Sentence
              child: 
                (command.Pipeline
                  children: [
                    (C {(echo)} {(DQ ($ VSub_DollarName '$epoch'))})
                    (C {(grep)} {(-Fq)} {(DQ (.))})
                  ]
                  negated: F
                )
              terminator: <Op_Semi ';'>
            )
          ]
          action: [
            (command.ShAssignment
              pairs: [
                (assign_pair
                  lhs: (sh_lhs_expr.Name name:seconds)
                  op: Equal
                  rhs: 
                    {
                      (command_sub
                        left_token: <Left_Backtick '`'>
                        command_list: 
                          (command.CommandList
                            children: [
                              (command.Pipeline
                                children: [
                                  (C {(echo)} {($ VSub_DollarName '$epoch')})
                                  (C {(cut)} {(-d.)} {(-f1)})
                                ]
                                negated: F
                              )
                            ]
                          )
                      )
                    }
                )
              ]
            )
            (command.If
              arms: [
                (if_arm
                  cond: [
                    (command.Sentence
                      child: 
                        (command.Pipeline
                          children: [
                            (C {(echo)} {($ VSub_DollarName '$epoch')})
                            (C {(grep)} {(-Eq)} {(DQ (Lit_Other '\\') ('.0+') (Lit_Other '$'))})
                          ]
                          negated: F
                        )
                      terminator: <Op_Semi ';'>
                    )
                  ]
                  action: [
                    (command.ShAssignment
                      pairs: [
                        (assign_pair
                          lhs: (sh_lhs_expr.Name name:epoch)
                          op: Equal
                          rhs: {($ VSub_DollarName '$seconds')}
                        )
                      ]
                    )
                  ]
                )
              ]
              else_action: [
                (command.ShAssignment
                  pairs: [(assign_pair lhs:(sh_lhs_expr.Name name:checkns) op:Equal rhs:{(DQ (true))})]
                )
              ]
            )
          ]
        )
      ]
    )
    (C 
      {
        (braced_var_sub
          token: <VSub_Name EDITOR>
          suffix_op: (suffix_op.Unary op_id:VTest_ColonHyphen arg_word:{(vim)})
        )
      } {(DQ ($ VSub_DollarName '$file'))}
    )
    (command.AndOr
      ops: [Op_DAmp Op_DPipe]
      children: [
        (C {(Lit_LBracket '[')} {(KW_Bang '!')} {(DQ ($ VSub_DollarName '$seconds'))} 
          {(Lit_RBracket ']')}
        )
        (command.ShAssignment
          pairs: [(assign_pair lhs:(sh_lhs_expr.Name name:err) op:Equal rhs:{(DQ (/dev/tty))})]
        )
        (command.ShAssignment
          pairs: [(assign_pair lhs:(sh_lhs_expr.Name name:err) op:Equal rhs:{(DQ (/dev/null))})]
        )
      ]
    )
    (command.Simple
      words: [
        {(touch)}
        {(DQ ($ VSub_DollarName '$file'))}
        {(--date) (Lit_Equals '=') (DQ ('1970-01-01 UTC ') ($ VSub_DollarName '$epoch') (' seconds'))}
      ]
      redirects: [(redir.Redir op:<Redir_Great '2>'> fd:2 arg_word:{($ VSub_DollarName '$err')})]
    )
    (command.If
      arms: [
        (if_arm
          cond: [
            (command.Sentence
              child: 
                (C {(Lit_LBracket '[')} {($ VSub_QMark '$?')} {(-ne)} {(0)} {(-a)} 
                  {(DQ ($ VSub_DollarName '$seconds'))} {(Lit_RBracket ']')}
                )
              terminator: <Op_Semi ';'>
            )
          ]
          action: [
            (command.AndOr
              ops: [Op_DAmp]
              children: [
                (C {(touch)} {(DQ ($ VSub_DollarName '$file'))} 
                  {(--date) (Lit_Equals '=') 
                    (DQ ('1970-01-01 UTC ') ($ VSub_DollarName '$seconds') (' seconds'))
                  }
                )
                (command.Simple
                  words: [{(echo)} {(DQ ('Warning: sub second portion of timestamp ignored'))}]
                  redirects: [(redir.Redir op:<Redir_GreatAnd '>&'> fd:16777215 arg_word:{(2)})]
                )
              ]
            )
          ]
        )
      ]
      else_action: [
        (command.If
          arms: [
            (if_arm
              cond: [
                (command.Sentence
                  child: 
                    (C {(Lit_LBracket '[')} {(DQ ($ VSub_DollarName '$checkns'))} {(Lit_RBracket ']')})
                  terminator: <Op_Semi ';'>
                )
              ]
              action: [
                (command.ShAssignment
                  pairs: [
                    (assign_pair
                      lhs: (sh_lhs_expr.Name name:new_ts)
                      op: Equal
                      rhs: 
                        {
                          (command_sub
                            left_token: <Left_Backtick '`'>
                            command_list: 
                              (command.CommandList
                                children: [
                                  (C {(date)} 
                                    {(--reference) (Lit_Equals '=') (DQ ($ VSub_DollarName '$file'))} {(Lit_Other '+') (Lit_Other '%') (s.) (Lit_Other '%') (N)}
                                  )
                                ]
                              )
                          )
                        }
                    )
                  ]
                )
                (command.ShAssignment
                  pairs: [
                    (assign_pair
                      lhs: (sh_lhs_expr.Name name:diff)
                      op: Equal
                      rhs: 
                        {
                          (command_sub
                            left_token: <Left_Backtick '`'>
                            command_list: 
                              (command.CommandList
                                children: [
                                  (command.Pipeline
                                    children: [
                                      (C {(echo)} 
                                        {
                                          (DQ ('((') ($ VSub_DollarName '$epoch') (-) 
                                            ($ VSub_DollarName '$new_ts') (')*10^9)/1')
                                          )
                                        }
                                      )
                                      (C {(bc)})
                                    ]
                                    negated: F
                                  )
                                ]
                              )
                          )
                        }
                    )
                  ]
                )
                (command.If
                  arms: [
                    (if_arm
                      cond: [
                        (command.Sentence
                          child: 
                            (C {(Lit_LBracket '[')} {($ VSub_DollarName '$diff')} {(-ne)} {(0)} 
                              {(Lit_RBracket ']')}
                            )
                          terminator: <Op_Semi ';'>
                        )
                      ]
                      action: [
                        (command.Simple
                          words: [
                            {(echo)}
                            {(DQ ('Warning: timestamp set ') (${ VSub_Name diff) ('ns backwards'))}
                          ]
                          redirects: [(redir.Redir op:<Redir_GreatAnd '>&'> fd:16777215 arg_word:{(2)})]
                        )
                      ]
                    )
                  ]
                )
              ]
            )
          ]
        )
      ]
    )
  ]
)