Purpose
The ftell64_ function returns the offset of the current byte relative to the beginning of the file associated with the specified logical unit UNIT. The ftell64 function allows you to query files larger than 2 gigabytes in large file enabled file systems.
The offset returned by the ftell_ function is the result of previously completed I/O operations. No references to ftell64_ on a unit with outstanding asynchronous data transfer operations are allowed until the matching WAIT statements for all outstanding asynchronous data transfer operations on the same unit are executed.
Class
Function
Argument Type and Attributes
Result Type and Attributes
The offset returned by the ftell64_ function is the absolute offset of the current byte relative to the beginning of the file. This means that all bytes from the beginning of the file to the current byte are counted, including the data of the records and record terminators if they are present.
ftell64_ returns INTEGER(8).
Result Value
If the unit is not connected, the ftell64_ function returns
-1.