FileRead¶
Transfers data from a unit into variables.
Declaration¶
Syntax¶
FileRead(int label, expr? unit, expr? fmt, expr? iomsg, expr? iostat,
expr? advance, expr? size, expr? id, expr? pos, expr* values,
stmt? overloaded, bool is_formatted, symbol? nml, expr? rec,
expr? pad)
Arguments¶
Argument |
Description |
|---|---|
|
the statement label of the Fortran statement, or |
|
the unit number to act on. |
|
the format, or |
|
a variable receiving the error message when the operation fails. |
|
a variable receiving the I/O status: zero on success, non-zero otherwise. The statement does not abort when it is present. |
|
|
|
a variable receiving the number of characters transferred in a non-advancing read. |
|
the identifier of an asynchronous transfer. |
|
the file position for a stream access read. |
|
the input list: the variables the data is read into. |
|
the call implementing a user-defined derived type input procedure. |
|
|
|
the Namelist group for a namelist read. |
|
the record number for a direct access read. |
|
|
Return values¶
None.
Description¶
The input list is a list of expressions rather than a list of variables, because an item may be an array section, a component or an ImpliedDoLoop. Every one of them must be writable.
With nml, values is empty: a namelist read transfers the variables of the
group, matching them by name in the file.
Examples¶
(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
)
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 []
)