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/*
** isRamDsk() - Determine if a drive is a RAM disk
**
** Call with drive letter ('a' - 'z', 'A' - 'Z')
**
** Returns TRUE, FALSE, or ERROR
**
** Uses ABSDISKC.C, ABSDISK.ASM, and DOS5BOOT.H from SNIPPETS
** (Note: The relevent parts of the structure in DOS5BOOT.H are
** also applicable to lower version numbers of DOS)
**
** Public domain by Bob Stout
*/
#include <stdlib.h>
#include <ctype.h>
#include <dos.h>
#include "dos5boot.h"
int AbsDiskRead(unsigned short, size_t, size_t, void *);
typedef enum {ERROR = -1, FALSE, TRUE} LOGICAL;
LOGICAL isRamDsk(unsigned char drive)
{
union REGS regs;
B_REC buffer;
regs.x.ax = 0x4408; /* Not if removable */
regs.h.bl = (unsigned)toupper(drive) - (unsigned char)'@';
intdos(®s, ®s);
if (0 == regs.x.ax)
return FALSE;
if (AbsDiskRead(toupper(drive) - 'A', 1, 0, &buffer))
return ERROR;
return (1 == buffer.bsFATs);
}
#ifdef TEST
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
if (2 > argc)
{
puts("Syntax: ISRAMDSK drive_letter");
return EXIT_FAILURE;
}
printf("Drive %c: is%s a RAM drive\n", toupper(*argv[1]),
isRamDsk(*argv[1]) ? "" : " not");
return EXIT_SUCCESS;
}
#endif /* TEST */
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