ms-dos-3.3/SRC/LIBC/DPB.C

/* dpb.c - retrieve DPB for physical drive */

#include "types.h"
#include "sysvar.h"
#include "dpb.h"
#include "cds.h"

extern char NoMem[], ParmNum[], BadParm[] ;
extern struct sysVarsType SysVars ;


/* Walk the DPB list trying to find the appropriate DPB */

long GetDPB(i)
int i ;
{
	struct DPBType DPB ;
	struct DPBType *pd = &DPB ;
	struct DPBType far *dptr ;
	int j ;

	*(long *)(&dptr) = DPB.nextDPB = SysVars.pDPB ;
	DPB.drive = -1 ;

	while (DPB.drive != i) {
		if ((int)DPB.nextDPB == -1)
			return -1L ;

		*(long *)(&dptr) = DPB.nextDPB ;

		for (j=0 ; j <= sizeof(DPB) ; j++)
			 *((char *)pd+j) = *((char far *)dptr+j) ;

	} ;
	return (long)dptr ;
}