| Seek Statement |
Syntax
Seek [#]filenumber, position
filenumber
Use: Required
Data Type: Integer
Any valid file number.
position
Use: Required
Data Type: Long Integer
Any whole number between 1 and 2,147,483,647.
Description
Places the read/write marker at a given position where the next read/write operation should occur.
Rules at a Glance
If the file has been opened in random mode, position refers to the next record number that should be read or written.
In all other file open modes (append, binary, input, and output), position is the byte where the next read or write operation will start.
The use of a record number in any subsequent Get or Put statement overrides the position set by the Seek method.
The size of a file can be increased as the result of a write operation that is performed after a Seek statement in which position is beyond the end of the file.
If position is or negative, a runtime error is generated.
Programming Tips and Gotchas
Unused records in a random access data file aren't necessarily blank. For example, if you open a brand new data file, then perform a seek operation to record 10 and write a new record, the preceding nine records are filled with binary data that was present on the section of the disk used by the new file prior to its creation.