(command.CommandList
  children: [
    (command.ShAssignment
      pairs: [
        (assign_pair
          lhs: (sh_lhs_expr.Name name:width)
          op: assign_op.Equal
          rhs: {<72>}
          spids: [10]
        )
      ]
    )
    (command.If
      arms: [
        (if_arm
          cond: [
            (command.Sentence
              child: 
                (C {<Id.Lit_LBracket '['>} {<Id.KW_Bang '!'>} {<-r>} {(DQ ($ Id.VSub_Number '$1'))} 
                  {<Id.Lit_RBracket ']'>}
                )
              terminator: <Id.Op_Semi _>
            )
          ]
          action: [
            (command.Simple
              words: [{<echo>} {(DQ <'Cannot read file '> ($ Id.VSub_Number '$1'))}]
              redirects: [(redir op:<Id.Redir_GreatAnd '>&'> loc:(redir_loc.Fd fd:1) arg:{<2>})]
              do_fork: T
            )
            (command.Sentence
              child: 
                (command.Simple
                  words: [{<echo>} {(DQ <'Usage: '> ($ Id.VSub_Number '$0') <' filename'>)}]
                  redirects: [(redir op:<Id.Redir_GreatAnd '>&'> loc:(redir_loc.Fd fd:1) arg:{<2>})]
                  do_fork: T
                )
              terminator: <Id.Op_Semi _>
            )
            (command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<1>})
          ]
          spids: [14 30]
        )
      ]
    )
    (command.WhileUntil
      keyword: <Id.KW_While while>
      cond: [(C {<read>} {<input>})]
      body: 
        (command.DoGroup
          children: [
            (command.If
              arms: [
                (if_arm
                  cond: [
                    (command.Sentence
                      child: 
                        (C {<Id.Lit_LBracket '['>} 
                          {(braced_var_sub token:<Id.VSub_Name input> prefix_op:(Id.VSub_Pound))} {<-gt>} {($ Id.VSub_DollarName '$width')} {<Id.Lit_RBracket ']'>}
                        )
                      terminator: <Id.Op_Semi _>
                    )
                  ]
                  action: [
                    (command.Pipeline
                      children: [(C {<echo>} {(DQ ($ Id.VSub_DollarName '$input'))}) (C {<fmt>})]
                      negated: F
                    )
                  ]
                  spids: [72 89]
                )
              ]
              else_action: [(C {<echo>} {(DQ ($ Id.VSub_DollarName '$input'))})]
            )
          ]
        )
      redirects: [(redir op:<Id.Redir_Less '<'> loc:(redir_loc.Fd fd:0) arg:{($ Id.VSub_Number '$1')})]
    )
    (command.ControlFlow token:<Id.ControlFlow_Exit exit> arg_word:{<0>})
  ]
)