.DRADS - set library default for disk caching (RADS).

Usage:

B:
   %b/manif/rads
   old = .drads( [option] );

C:
   #include <host_io.h>
   int _drads( [int option] );

Where:

option

is a symbolic constant indicating the default you want to set. Possibilities are:

RADS_BYPASS

bypasses the system cache.

RADS_WINTO

writes only into the system cache.

RADS_WTHRU

writes both cache and disk.

RADS_QUERY

returns current library setting without changing the default.

RADS_SYS

resets your program's default RADS setting to the system default.

If you omit the "option" argument, .DRADS assumes RADS_QUERY. This means that .DRADS returns the current library setting without changing the default.

old

is the previous value of your program's RADS default. If you omitted the "option" argument, .DRADS returns the current default without changing the setting.

Description:

.DRADS lets you set a default for the way your program uses GCOS8's disk caching abilities (RADS). This only affects dynamically accessed permanent files.

If you use .DRADS to set the default to something other than RADS_SYS, the I/O library automatically calls the .RADS function every time it accesses a permanent file. This call to .RADS specifies the default setting established by the most recent call to .DRADS.

If you do not use .DRADS to set a default, or if the default is set to RADS_SYS, the I/O library does not call .RADS when it opens an I/O unit. This means that the I/O unit will use the default specified by the system administrator. You can override the default for a particular I/O unit by calling .RADS after the file has been opened. For statically allocated files, non-default cache handling can be specified with options on the $PRMFL card, or by a explicit call to .RADS.

Notes:

.DRADS has no effect in TSS. It only applies to batch programs (including NS mode programs).

See Also:

expl b lib .rads

The Rapid Access Data System Manual, EA67

Copyright © 1996, Thinkage Ltd.