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Home > Class Reference > %SYS namespace > %Library.FileCharacterStream

%Library.FileCharacterStream

stream class %Library.FileCharacterStream extends %Library.CharacterStream, %Library.FileStreamAdaptor

Stream class that stores character data in external files. This class is deprecated in favor of %Stream.FileCharacter. For example the following code opens a file character stream, points it at a particular file on the filesystem and then reads it in line by line:
  Set stream=##class(%FileCharacterStream).%New()
  Set stream.Filename="c:\myfile.txt"
  While 'stream.AtEnd {
  Set line=stream.ReadLine()
  ; Process the line here
  }
  
The difference between file character stream and file binary streams is that the character stream understands that it is writing character data and this may be subject to characterset translation. For example you may wish to utf-8 encode character data being written to the file, but with a binary file stream it is just a series of binary data and so this is always read/written exactly as it is without and translation. Also the file is written in 'S' mode so for example writing cr/lf on a unix system will just append lf as this is the unix line terminator.

Property Inventory (Including Private)

Method Inventory (Including Private)

Parameters

parameter OPENAPPEND = AWS;
parameter OPENREAD = RU;
parameter OPENREADTERM = RS;
parameter OPENWRITE = WSN;

Properties (Including Private)

property BOM as %String [ Transient ];
BOM characters that appear at start of file to signify which encoding it is using
Property methods: BOMDisplayToLogical(), BOMGet(), BOMIsValid(), BOMLogicalToDisplay(), BOMLogicalToOdbc(), BOMNormalize(), BOMSet()
property StreamFormatWrite as %Boolean [ InitialExpression = '$$$isVMS , Transient ];
The StreamFormatWrite property controls whether file output is in stream or undefined format. If StreamFormatWrite is 1 (true), the default on Windows/Unix, the file is written in S (stream) format. If StreamFormatWrite is 0 (false), the default on VMS, the file is written in U (Undefined) format. For Unix file output, S format converts crlf to lf which can be a problem for MIME output such as email. The user can now set messagepart.TextData.StreamFormatWrite=0 to keep crlf in text message parts of the mail message.
Property methods: StreamFormatWriteDisplayToLogical(), StreamFormatWriteGet(), StreamFormatWriteIsValid(), StreamFormatWriteLogicalToDisplay(), StreamFormatWriteNormalize(), StreamFormatWriteSet()
property TranslateTable as %String [ InitialExpression = "0" , Transient ];
The translation table to be used when reading or writing the file.
Initial value of 0 indicates that the table has not yet been set.
If translation table is set after the file has been opened then switch the table used for the file. If the translation table is set to "", then the "RAW" table is used.
Property methods: TranslateTableDisplayToLogical(), TranslateTableGet(), TranslateTableIsValid(), TranslateTableLogicalToDisplay(), TranslateTableLogicalToOdbc(), TranslateTableNormalize(), TranslateTableSet()

Methods (Including Private)

method %Oid() as %ObjectIdentity
Returns the OID of this object.
private method %OnConstructClone(object As %RegisteredObject, deep As %Boolean = 0, ByRef cloned As %String) as %Status
Inherited description: This callback method is invoked by the %ConstructClone() method to provide notification that a clone of an object is being created. It passes in the oref of the object that was cloned in object.

If this method returns an error then the object will not be created.

private method GetReadOpenParameter(filename As %String, mode As %Integer, ByRef pos As %Integer) as %String
private method GetWriteOpenParameter(filename As %String, mode As %Integer) as %String
method IsFileUnicode() as %Boolean
Returns true if the file is Unicode. This method may only be called after data has been read from the file stream.
method SizeGet() as %Integer
Return the current size of the data stream. Note this is complicated by having to worry about the translate table used to write the file. VMS does not support moving to a position in a file or providing the current position in a file. On VMS if a BOM is included at the start of the file it may be included in the size calculated.
method TranslateTableSet(table As %String) as %Status
If translation table is set after the file has been opened then switch the table used for the file. If the translation table is set to "", then the "RAW" table is used.

Inherited Members

Inherited Properties (Including Private)

Inherited Methods (Including Private)

Subclasses