The FILE STATUS clause of the FILE-CONTROL paragraph allows for each file to be associated with a file status key (i.e.,the 2-character data item specified in the FILE STATUS clause). If the FILE STATUS clause is specified for a given file, a value indicating the status of each I/O operation against that file is placed in the associated file status key. This value is stored in the file status key as soon as the I/O operation is completed (and before execution of any EXCEPTION/ERROR declarative or INVALIDKEY/AT END phrase associated with the I/O request).
Note: This element may behave differently when the CMPR2 compiler option is used. The file status key is divided into two status keys: the first character is known as file status key 1; the second character is file status key 2.