LFPOINT_LUN Procedure

Allows the current position of the specified file to be set to any arbitrary point in the file. This routine is for large files (>2.5 gigabytes on supported platforms only).

Note: On the HP-UX operating system the largest value you can pass to this function is 4294967295, the maximum value of an unsigned long integer. If you need to position the file pointer beyond this point, read a dummy variable to reposition the pointer to the desired location.

Usage

LFPOINT_LUN, unit, position

Input Parameters

unit—The file unit (logical unit number) for which the file position will be set. This keyword can be set to either unit or –unit. If –unit is specified, the current position of the file pointer is returned in the output parameter position.

position—A string specifying the position of the file pointer as a byte offset from the start of the file.

Output Parameters

position—If –unit is specified, the current position of the file pointer (in bytes) is returned in the position parameter.

Keywords

None.

Discussion

LFPOINT_LUN is for the PV-WAVE programmer who wants explicit control over positioning for reading or writing within a large file. It is seldom used for general file I/O operations.

See Also

FREE_LUN, FSTAT, GET_LUN, OPEN (UNIX), OPEN (Windows), READ, WRITEU, LFSTAT

For more information, see the section Positioning File Pointers in Chapter 8 of the PV‑WAVE Programmer’s Guide.