> For the complete documentation index, see [llms.txt](https://documentation.astera.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://documentation.astera.com/astera-data-stack-v8/dataflows/sources/cobol-file-source.md).

# COBOL File Source

The Astera *COBOL File Source* provides the functionality to read a COBOL file. Astera features a high-speed COBOL file reader capable of efficiently processing large COBOL files. *COBOL File Source* features include:

**Copybook Parsing**

Centerprise features a built-in parser that reads COBOL copybook specifications and automatically builds layout. Where a copybook is not available, you can treat the file as a standard fixed-length file visually define field markers, and specify data types and numeric formats.

**REDEFINES, OCCURS, and OCCURS DEPENDING**

The *COBOL File Source* provides full support for REDEFINES, OCCURS, and OCCURS DEPENDING. For REDEFINES, you can specify values that will be used to identify individual record types. These values can be defined as strings or regular expressions.

**Numeric Formats and Encodings**

The *COBOL File Source* supports conversion for numeric types including COMP, COMP-1, COMP-2, COMP-3, COMP-4, and Zoned Decimal as well as a wide range of encodings and character sets.

**Steps**

Adding a *COBOL File Source* object allows you to transfer data from a COBOL file. An example of what a COBOL file source object looks like is shown below.

![](https://750977703-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FqHxyVNGb7tSdIWecl6Ru%2Fuploads%2Fsy4TPdSkq2gGd79qIX2Q%2F0.png?alt=media)

To configure the properties of a *COBOL File Source* object after it was added to the dataflow, right-click on it and select *Properties* from the context menu.

{% embed url="<https://youtu.be/wkEVahIdU9U>" %}


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