pdp11v/usr/src/cmd/sccs/lib/date_ab.c

# include	"sys/types.h"
# include	"macros.h"
# include	"time.h"

SCCSID(@(#)date_ab.c	5.4);
/*
	Function to convert date in the form "yymmddhhmmss" to
	standard UNIX time (seconds since Jan. 1, 1970 GMT).
	Units left off of the right are replaced by their
	maximum possible values.

	The function corrects properly for leap year,
	daylight savings time, offset from Greenwich time, etc.

	Function returns -1 if bad time is given (i.e., "730229").
*/
#define	dysize(A) (((A)%4)? 365: 366)

char *Datep;
static int dmsize[12]={31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};


date_ab(adt,bdt)
char *adt;
long *bdt;
{
	int y, t, d, h, m, s, i;
	long tim;
	struct tm *localtime();
	extern long timezone;

	tzset();
	Datep = adt;

	if((y=g2()) == -2) y = 99;
	if(y<70 || y>99) return(-1);

	if((t=g2()) == -2) t = 12;
	if(t<1 || t>12) return(-1);

	if((d=g2()) == -2) d = mosize(y,t);
	if(d<1 || d>mosize(y,t)) return(-1);

	if((h=g2()) == -2) h = 23;
	if(h<0 || h>23) return(-1);

	if((m=g2()) == -2) m = 59;
	if(m<0 || m>59) return(-1);

	if((s=g2()) == -2) s = 59;
	if(s<0 || s>59) return(-1);

	tim = 0L;
	y += 1900;
	for(i=1970; i<y; i++)
		tim += dysize(i);
	while(--t)
		tim += mosize(y,t);
	tim += d - 1;
	tim *= 24;
	tim += h;
	tim *= 60;
	tim += m;
	tim *= 60;
	tim += s;

	tim += timezone;			/* GMT correction */
	if((localtime(&tim))->tm_isdst)
		tim += -1*60*60;		/* daylight savings */
	*bdt = tim;
	return(0);
}


mosize(y,t)
int y, t;
{

	if(t==2 && dysize(y)==366) return(29);
	return(dmsize[t-1]);
}


g2()
{
	register int c;
	register char *p;

	for (p = Datep; *p; p++)
		if (numeric(*p))
			break;
	if (*p) {
		c = (*p++ - '0') * 10;
		if (*p)
			c += (*p++ - '0');
		else
			c = -1;
	}
	else
		c = -2;
	Datep = p;
	return(c);
}