The leftmost character position of the FILE STATUS data item is known as status key 1 and is set to indicate one of the following conditions upon completion of the input-output operation on a file of any organization.
The meaning of the above conditions is as follows:
| "0" | Successful completion. The input-output statement was successfully executed. |
| "1" | At end. The sequential READ statement was unsuccessfully executed either because of an attempt to read a record when no next logical record exists in the file or because the first READ statement was executed for a file described with the OPTIONAL clause when that file was not available at the time its associated OPEN statement was executed. |
| "2" | Invalid key. The input-output statement on a non-sequential file was unsuccessfully executed because of one of the following:
Sequence error Duplicate key No record found Boundary violation |
| "3" | Permanent error. The input-output statement was unsuccessfully executed because of a boundary violation for a sequential file or because of an input-output error, such as a data check parity error or transmission error. |
| "4" | Logic error. The input-output statement was unsuccessfully executed, either because an improper sequence of input-output operations was performed on the file, or because a limit you defined was violated. |
| "9" | Run-time system error message. The input-output statement was unsuccessfully executed because of a condition that is specified by the run-time system error message number. This value is used only to indicate a condition not indicated by other defined values of status key 1, or by specified combinations of the values of status key 1 and status key 2. |