The I/O status specifier designates a variable to store a value indicating the status of a data transfer operation. It takes the following form:
|A positive integer||Indicating an error condition occurred.|
|A negative integer||Indicating an end-of-file or end-of-record condition occurred. The negative integers differ depending on which condition occurred.|
|Zero||Indicating no error, end-of-file, or end-of-record condition occurred.|
Execution continues with the statement following the data transfer statement, or the statement identified by a branch specifier (if any).
An end-of-file condition occurs only during execution of a sequential READ statement; an end-of-record condition occurs only during execution of a nonadvancing READ statement.
On OpenVMS systems, secondary operating system messages do not display when IOSTAT is specified. To display these messages, remove IOSTAT or use a platform-specific method such as an OpenVMS condition handler.
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