Oct 95 Tips

Volume Number: 11

Issue Number: 10

Column Tag: Tips & Tidbits

Tips & Tidbits

By Steve Sisak, Contributing Editor

Note: Source code files accompanying article are located on MacTech CD-ROM or

source code disks.

TIP OF THE MONTH

Spotting the Elusive Ram Disk

Here is a handy function for performing a dynamic check for the existence of a

RAM disk as created by Apple’s Memory control panel. I use it in some of my programs

when speed is paramount. Since the user can remove the RAM disk at any time by

turning it off from the Memory control panel, and can rename it at any time, the code

here must be called before using the RAM disk. In other words, don’t check just once

during your application startup and assume thereafter that it will still be there, check

before each access if possible. Program defensively...

- Greg Poole

HasRamDisk.h

#pragma once

#ifdef __cplusplus

extern "C" {
#endif

extern Boolean HasRamDisk( FSSpecPtr ramDiskSpec );

#ifdef __cplusplus

}

#endif

HasRamDisk.c

/******************************************************************************

HasRamDisk.c

A dynamic check for the existence of a RAM disk as created by Apple's

Memory control panel. Since the user can remove the RAM disk at any time

by turning it off from the Memory control panel, and can rename it at any

time, the code here needs to be called before assuming the existence of

a RAM disk. In other words, don't check just once during your application

startup and assume thereafter that it will still be there, check

before each access. Program defensively...

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