# Striim 3.9.6 documentation

##### Creating the FileReader output stream type automatically

When FileReader is used with DSVParser, the type for the output stream can be created automatically from the file header using OUTPUT TO <stream name> MAP(filename:'<source file name>'). A regular, unmapped output stream must also be specified. For example:

CREATE SOURCE PosSource USING FileReader (
wildcard: 'PosDataPreview*.csv',
directory: 'Samples/PosApp/appData',
positionByEOF:false )
PARSE USING DSVParser (
trimquote:false
)
OUTPUT TO PosSource_Stream,
OUTPUT TO PosSource_Mapped_Stream MAP(filename:'PosDataPreview.csv');


Notes:

• When you use a MAP clause, you may not specify the Column Delimit Till. Header Line No, Line Number, or No Column Delimiter properties.

• The file specified in the MAP clause must be in the directory specified by FileWriter's directory property when the source is created.

• The header must be the first line of that file.

• The column names in the header can contain only alphanumeric, _ (underscore) and \$ (dollar sign) characters, and may not begin with numbers.

• All files to be read must be similar to the one specified in the MAP clause, with headers (which will be ignored) in the first line and the same number of fields.

• All fields in the output stream type will be of type String.

• In this release, this feature is available only in the console, the MAP clause cannot be edited in the web UI, and changing the Wildcard property value in the web UI will break the source.