Figure 6-10. Nested HPFOPEN/FOPEN and FCLOSE Pairs

Nesting of HPFOPEN or FOPEN and FCLOSE pairs keeps a tape that has been FCLOSE d from rewinding. A tape closed with the TEMP, no-rewind disposition is rew ound and unloaded unless the process closing it has another ￿le curren tly open on the device.

For detailed information on ￿le disposition, end-of-￿le marks, and use of FCLOSE with magnetic tape, refer to Accessing Files Pr ogrammer's Guide (32650-90017).

Using Files at Run Time

At run time, y ou can perform the follo wing operations with ￿les:

Identify disc ￿les to use

Use a system-de￿ned ￿le

Use a device ￿le

Specify closing disposition of a ￿le

Create a ￿le, as needed

Determine operations allo wed for a ￿le

De￿ne ￿le accessibilit y

6-20 File System