External Files :: SAS(R) 9.3 Intelligence Platform: Data Administration Guide, Second Edition

An external file is a file that is maintained by the machine operating environment or by a software product other than SAS. A flat file with comma-separated values is one example. SAS Data Integration Studio provides three source designer wizards that enable you to create metadata objects for external files:

the delimited external file wizard for external files in which data values are separated with a delimiter character. This wizard enables you to specify multiple delimiters, nonstandard delimiters, missing values, and multi-line records.
the fixed-width external file wizard for external files in which data values appear in columns that are a specified number of characters wide. This wizard enables you to specify non-contiguous data.
the user-written external file wizard for complex external files that require user-written SAS code to access their data.

The external file source designer wizards enable you to do the following:

display a raw view of the data in the external file
display a formatted view of the data in the external file, as specified in the SAS metadata for that file
display the SAS DATA step and SAS INFILE statement that the wizard generates for the selected file
display the SAS log for the code that is generated by the wizard
specify options for the SAS INFILE statement that is generated by the wizard, such as National Language Support (NLS) encoding
override the generated SAS INFILE statement with a user-written statement
supply a user-written SAS DATA step to access an external file

The following figure shows establishing connectivity to external files:

For a detailed example of an external file connection, see Establishing Connectivity to a Flat File.