File status 10 unexpected end of file

VSAM file status 10: End of file — sequential READ reached the last record.

What it means

• End of file — sequential READ reached the last record.
• Not an error: it is the normal loop terminator.

Common causes

• Program treats end-of-file as an error.
• READ NEXT issued after EOF without handling.

How to diagnose

• Use AT END to set an EOF flag.
• Structure the loop around the flag.

How to fix it

• Handle AT END explicitly in every sequential read loop.

Example: Always check FILE STATUS after I/O

FILE STATUS after every I/O turns mystery failures into clear codes.

Interview tip

• Q: How would you troubleshoot a File status 10 unexpected end of file in production?
• A: I would confirm the exact file status code, check the JCL DD and catalog, then apply the specific fix.

Prevention checklist

• Check FILE STATUS after every OPEN/READ/WRITE.
• Keep FD layouts in sync with cluster definitions.