cmosclk.c

访问AT机CMOS和时钟.zip

#define MSC		1
#define MSDOS	1

#include <stdio.h>
#if MSC 
#include <stdlib.h>
#include <dos.h>
#endif


/*
 * cmosclk.
 *
 *
 * See below for more information.
 *
 */


char	*documentation[] = {
"cmosclk either sets the CMOS date/time from the MS-DOS date/time",
"    or         sets the MS-DOS date/time from the CMOS date/time",
"   cmosclk [flags]",
"",
"Flags are single characters preceeded by '-':",
"   -w      Write the CMOS date/time from the MS-DOS date/time",
"   -r      Read the CMOS date/time into the MS-DOS date/time",
"   -s      Write the CMOS date/time to STDOUT (mm/dd/yy hh:mm:ss)",
"   -t      Write the CMOS time only to STDOUT (hh:mm:ss)",
"   -d      Write the CMOS date only to STDOUT (mm/dd/yy)",
"",
0 };


#ifndef stdin
#define stdin STDIN
#define stdout STDOUT
#define stderr STDERR
#endif

#define LMAX	512		/* max number of entries per directory */

int	wflag = 0;
int	rflag = 1;		/* default to read the CMOS time into the MS-DOS time */
int	sflag = 0;
int	tflag = 0;
int	dflag = 0;

int	debug	=	0;	   /* Set for debug code      */


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

main(argc, argv)
char *argv[];
int argc;
{
	register int c;
	register char *p;
	int nfile, i;

   if (argc <= 1)
      usage("No arguments");
   if (argc == 2 && argv[1][0] == '?' && argv[1][1] == 0) {
      help(documentation);
      return;
      }
   nfile = argc-1;
   for (i=1; i < argc; ++i) {
      p = argv[i];
      if (*p == '-') {
	 ++p;
	 while (c = *p++) {
	    switch(tolower(c)) {

	    case '?':
	       help(documentation);
	       return;

	    case 'x':
	       ++debug;
	       break;

	    case 's':
	       tflag = dflag = sflag = 1;
	       rflag = wflag = 0;
	       break;

	    case 't':
	       sflag = tflag = 1;
	       rflag = wflag = 0;
	       break;

	    case 'd':
	       sflag = dflag = 1;
	       rflag = wflag = 0;
	       break;

	    case 'r':
	       rflag = 1;
	       sflag = wflag = 0;
	       break;

	    case 'w':
	       wflag = 1;
	       rflag = sflag = 0;
	       break;


	    default:
	       usage("Unknown flag");
	    }
	 }
	 argv[i] = 0;
	 --nfile;
      } 
   }
   if (nfile != 0)
      usage("No filenames are allowed.  cmosclk -? for instructions.");

   if (sflag || rflag)
   		readcmos();			/* read cmos date/time */
   else if (wflag)
   		writecmos();		/* write cmos date/time */
   else
   		usage("No flags set. cmosclk -? for instructions.");
}


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

int writecmos()
{
	union REGS inregs, outregs;

/*   set CMOS date from MS-DOS date */
	inregs.h.ah = 0x2a;			/* get date BDOS call */
	intdos(&inregs, &outregs);
	inregs.x.cx = b2bcd(outregs.x.cx);	/* yr */	/* convert to BCD */
	inregs.h.dh = b2bcd(outregs.h.dh);  /* mon */
	inregs.h.dl = b2bcd(outregs.h.dl);  /* day */
	inregs.h.ah = 5;						/* set date function */
	int86(0x1a, &inregs, &outregs);		/* call Real Time Clock interrupt */

/* set CMOS time from MS-DOS time */
	inregs.h.ah = 0x2c;		/* get time BDOS call */
	intdos(&inregs, &outregs);
	inregs.h.ch = b2bcd(outregs.h.ch);  /* hour */		/* convert to BCD */
	inregs.h.cl = b2bcd(outregs.h.cl);  /* min */
	inregs.h.dh = b2bcd(outregs.h.dh);  /* sec */
	inregs.h.dl = 0;					/* hundredths */
	inregs.h.ah = 3;						/* set time function */
	int86(0x1a, &inregs, &outregs);		/* call Real Time Clock interrupt */

}

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

int readcmos()
{
	union REGS inregs, outregs;

/*   set MS-DOS date from CMOS date */
	inregs.h.ah = 04;						/* get date function */
	int86(0x1a, &inregs, &outregs);		/* call Real Time Clock interrupt */
	inregs.x.cx = bcd2b(outregs.x.cx);	/* yr */	/* convert to BCD */
	inregs.h.dh = bcd2b(outregs.h.dh);  /* mon */
	inregs.h.dl = bcd2b(outregs.h.dl);  /* day */
	if (rflag) {
		inregs.h.ah = 0x2b;			/* set date BDOS call */
		intdos(&inregs, &outregs);
	}
	else if (dflag) {
		printf("%02d/%02d/%02d ", inregs.h.dh, inregs.h.dl, inregs.x.cx % 100);
	}

/* set MS-DOS time from CMOS time */
	inregs.h.ah = 02;						/* get time function */
	int86(0x1a, &inregs, &outregs);		/* call Real Time Clock interrupt */
	inregs.h.ch = bcd2b(outregs.h.ch);  /* hour */		/* convert to BCD */
	inregs.h.cl = bcd2b(outregs.h.cl);  /* min */
	inregs.h.dh = bcd2b(outregs.h.dh);  /* sec */
	inregs.h.dl = 0;					/* hundredths */
	if (rflag) {
		inregs.h.ah = 0x2d;		/* set time BDOS call */
		intdos(&inregs, &outregs);
	}
	else if (tflag) {
		printf("%02d:%02d:%02d\n ", inregs.h.ch, inregs.h.cl, inregs.h.dh);
	}

}

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

int b2bcd(bin)
int bin;
{
	int quotient, remainder, ret;

	if (bin > 9999)			/* BCD would overflow */
		return 0;

	ret = bin / 1000;	/* get first nibble */
	remainder = bin - (ret * 1000);
	quotient = remainder / 100;
	ret = (ret << 4) | quotient;
	remainder -= (quotient * 100);
	quotient = remainder / 10;
	ret = (ret << 4) | quotient;
	remainder -= (quotient * 10);
	ret = (ret << 4) | remainder;

	return ret;
}
		
/*******************************************************/

int bcd2b(bin)
int bin;
{
	int ret;

	ret = (bin & 0x0f) 						/* one's digit */
		+ ((bin >> 4) & 0x0f) * 10			/* ten's digit */
		+ ((bin >> 8) & 0x0f) * 100			/* hundred's digit */
		+ ((bin >> 12) & 0x0f) * 1000;		/* thousand's digit */

	return ret;
}
		
/*******************************************************/

usage(s)
char	*s;
{
   fputs("?CMOSCLK-E-", stdout);
   fputs(s, stdout);
   fputs("\n", stdout);
   fputs("Usage: cmosclk [-srw].   cmosclk ? for help\n", stdout);
   exit(1);
}