Data transfer statements take one of the following forms:
[UNIT=]io-unit | ADVANCE | ERR | KEYID (VMS only) |
[FMT=]format | END | IOSTAT | REC |
[NML=]group | EOR | KEY[con] (VMS only) | SIZE |
If a format specifier ([FMT=]format) or namelist specifier ([NML=]group) is present, the data transfer statement is called a formatted I/O statement; otherwise, it is an unformatted I/O statement.
If a record specifier (REC=) is present, the data transfer statement is a direct-access I/O statement; otherwise, it is a sequential-access I/O statement.
If an error, end-of-record, or end-of-file condition occurs during data transfer, file positioning and execution are affected, and certain control-list specifiers (if present) become defined. (For more information, see Branch Specifiers.)
Following sections describe the I/O control list and I/O lists.