FileOpen

Connects a unit to a file.

Declaration

Syntax

FileOpen(int label, expr? newunit, expr? filename, expr? status,
    expr? form, expr? access, expr? iostat, expr? iomsg, expr? action,
    expr? delim, expr? recl, expr? position, expr? blank,
    expr? encoding, expr? sign, expr? decimal, expr? round, expr? pad,
    expr? asynchronous)

Arguments

Argument

Description

label

the statement label of the Fortran statement, or -1 when it has none.

newunit

a variable receiving a unit number chosen by the runtime, for newunit=.

filename

the name of the file to connect.

status

old, new, replace, scratch or unknown.

form

formatted or unformatted.

access

sequential, direct or stream.

iostat

a variable receiving the I/O status: zero on success, non-zero otherwise. The statement does not abort when it is present.

iomsg

a variable receiving the error message when the operation fails.

action

read, write or readwrite.

delim

the delimiter used around character values in list-directed and namelist output.

recl

the record length of a direct access file.

position

asis, rewind or append.

blank

null or zero: how blanks in numeric input are read.

encoding

utf-8 or default.

sign

plus, suppress or processor_defined.

decimal

point or comma: the decimal edit mode.

round

the rounding mode for formatted conversion.

pad

yes or no: whether short input records are padded with blanks.

asynchronous

yes or no: whether asynchronous transfer is allowed on this unit.

Return values

None.

Description

Every specifier of the open statement has its own member, so nothing has to be recovered from a list of keyword arguments later. All of them are optional and a nil member means the specifier was not written, leaving the default to the runtime.

newunit and a user-chosen unit number are alternatives: with newunit= the runtime picks a free unit and stores it in that variable.

Examples

(FileOpen
  :label -1
  :newunit (Var
    :v (SymbolRef 1 "unit")
  )
  :filename (StringConstant
    :s "data.txt"
    :type (String
      :kind 1
      :len (IntegerConstant
        :n 8
        :type (Integer
          :kind 4
        )
        :intboz_type :Decimal
      )
      :len_kind :ExpressionLength
      :physical_type :DescriptorString
    )
  )
  :status (StringConstant
    :s "old"
    :type (String
      :kind 1
      :len (IntegerConstant
        :n 3
        :type (Integer
          :kind 4
        )
        :intboz_type :Decimal
      )
      :len_kind :ExpressionLength
      :physical_type :DescriptorString
    )
  )
  :form nil
  :access nil
  :iostat (Var
    :v (SymbolRef 1 "iostat")
  )
  :iomsg nil
  :action nil
  :delim nil
  :recl nil
  :position nil
  :blank nil
  :encoding nil
  :sign nil
  :decimal nil
  :round nil
  :pad nil
  :asynchronous nil
)

It comes from this complete ASR text document:

(TranslationUnit
  :symtab (SymbolTable
    :id 0
    :symbols {
      "main" (Program
        :symtab (SymbolTable
          :id 1
          :symbols {
            "exists" (Variable
              :parent_symtab 1
              :name "exists"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Logical
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "iostat" (Variable
              :parent_symtab 1
              :name "iostat"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Integer
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "n" (Variable
              :parent_symtab 1
              :name "n"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Integer
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
            "unit" (Variable
              :parent_symtab 1
              :name "unit"
              :dependencies []
              :intent :Local
              :symbolic_value nil
              :value nil
              :storage :Default
              :type (Integer
                :kind 4
              )
              :type_declaration nil
              :abi :Source
              :access :Public
              :presence :Required
              :value_attr false
              :target_attr false
              :contiguous_attr false
              :bindc_name nil
              :is_volatile false
              :is_protected false
              :pass_attr :NotMethod
              :self_argument nil
              :codims []
            )
          }
        )
        :name "main"
        :dependencies []
        :body [
          (FileOpen
            :label -1
            :newunit (Var
              :v (SymbolRef 1 "unit")
            )
            :filename (StringConstant
              :s "data.txt"
              :type (String
                :kind 1
                :len (IntegerConstant
                  :n 8
                  :type (Integer
                    :kind 4
                  )
                  :intboz_type :Decimal
                )
                :len_kind :ExpressionLength
                :physical_type :DescriptorString
              )
            )
            :status (StringConstant
              :s "old"
              :type (String
                :kind 1
                :len (IntegerConstant
                  :n 3
                  :type (Integer
                    :kind 4
                  )
                  :intboz_type :Decimal
                )
                :len_kind :ExpressionLength
                :physical_type :DescriptorString
              )
            )
            :form nil
            :access nil
            :iostat (Var
              :v (SymbolRef 1 "iostat")
            )
            :iomsg nil
            :action nil
            :delim nil
            :recl nil
            :position nil
            :blank nil
            :encoding nil
            :sign nil
            :decimal nil
            :round nil
            :pad nil
            :asynchronous nil
          )
          (FileRead
            :label -1
            :unit (Var
              :v (SymbolRef 1 "unit")
            )
            :fmt nil
            :iomsg nil
            :iostat (Var
              :v (SymbolRef 1 "iostat")
            )
            :advance nil
            :size nil
            :id nil
            :pos nil
            :values [
              (Var
                :v (SymbolRef 1 "n")
              )
            ]
            :overloaded nil
            :is_formatted true
            :nml nil
            :rec nil
            :pad nil
          )
          (FileWrite
            :label -1
            :unit (Var
              :v (SymbolRef 1 "unit")
            )
            :iomsg nil
            :iostat nil
            :id nil
            :values [
              (Var
                :v (SymbolRef 1 "n")
              )
            ]
            :separator nil
            :end nil
            :overloaded nil
            :is_formatted true
            :nml nil
            :rec nil
            :pos nil
            :asynchronous nil
          )
          (FileBackspace
            :label -1
            :unit (Var
              :v (SymbolRef 1 "unit")
            )
            :iostat nil
            :iomsg nil
            :err nil
          )
          (FileRewind
            :label -1
            :unit (Var
              :v (SymbolRef 1 "unit")
            )
            :iostat nil
            :err nil
            :iomsg nil
          )
          (FileEndfile
            :label -1
            :unit (Var
              :v (SymbolRef 1 "unit")
            )
            :iostat nil
            :iomsg nil
            :err nil
          )
          (Flush
            :label -1
            :unit (Var
              :v (SymbolRef 1 "unit")
            )
            :err nil
            :iomsg nil
            :iostat nil
          )
          (FileInquire
            :label -1
            :unit (Var
              :v (SymbolRef 1 "unit")
            )
            :file nil
            :iostat nil
            :err nil
            :exist (Var
              :v (SymbolRef 1 "exists")
            )
            :opened nil
            :number nil
            :named nil
            :name nil
            :access nil
            :sequential nil
            :direct nil
            :form nil
            :formatted nil
            :unformatted nil
            :recl nil
            :nextrec nil
            :blank nil
            :position nil
            :action nil
            :read nil
            :write nil
            :readwrite nil
            :delim nil
            :pad nil
            :flen nil
            :blocksize nil
            :convert nil
            :carriagecontrol nil
            :size nil
            :pos nil
            :iolength nil
            :iolength_vars []
            :decimal nil
            :sign nil
            :encoding nil
            :stream nil
            :iomsg nil
            :round nil
            :pending nil
            :asynchronous nil
          )
          (FileClose
            :label -1
            :unit (Var
              :v (SymbolRef 1 "unit")
            )
            :iostat nil
            :iomsg nil
            :err nil
            :status nil
          )
        ]
      )
    }
  )
  :items []
)

See Also

FileClose, FileRead, FileWrite, FileInquire