#include <u.h>#include <libc.h> #define	TZSIZE	150static	void	readtimezone(void);static	int	rd_name(char**, char*);static	int	rd_long(char**, long*);staticstruct{	char	stname[4];	char	dlname[4];	long	stdiff;	long	dldiff;	long	dlpairs[TZSIZE];} timezone; #define SEC2MIN 60L#define SEC2HOUR (60L*SEC2MIN)#define SEC2DAY (24L*SEC2HOUR) /* *  days per month plus days/year */static	int	dmsize[] ={	365, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};static	int	ldmsize[] ={	366, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; /* *  return the days/month for the given year */static int *yrsize(int y){	if((y%4) == 0 && ((y%100) != 0 || (y%400) == 0))		return ldmsize;	else		return dmsize;} /* * compute seconds since Jan 1 1970 GMT * and convert to our timezone. */longtm2sec(Tm *tm){	long secs;	int i, yday, year, *d2m; 	if(strcmp(tm->zone, "GMT") != 0 && timezone.stname[0] == 0)		readtimezone();	secs = 0; 	/*	 *  seconds per year	 */	year = tm->year + 1900;	for(i = 1970; i < year; i++){		d2m = yrsize(i);		secs += d2m[0] * SEC2DAY;	} 	/*	 *  if mday is set, use mon and mday to compute yday	 */	if(tm->mday){		yday = 0;		d2m = yrsize(year);		for(i=0; i<tm->mon; i++)			yday += d2m[i+1];		yday += tm->mday-1;	}else{		yday = tm->yday;	}	secs += yday * SEC2DAY; 	/*	 * hours, minutes, seconds	 */	secs += tm->hour * SEC2HOUR;	secs += tm->min * SEC2MIN;	secs += tm->sec; 	/*	 * Only handles zones mentioned in /env/timezone,	 * but things get too ambiguous otherwise.	 */	if(strcmp(tm->zone, timezone.stname) == 0)		secs -= timezone.stdiff;	else if(strcmp(tm->zone, timezone.dlname) == 0)		secs -= timezone.dldiff;	if(secs < 0)		secs = 0;	return secs;} staticvoidreadtimezone(void){	char buf[TZSIZE*11+30], *p;	int i; 	memset(buf, 0, sizeof(buf));	i = open("/env/timezone", 0);	if(i < 0)		goto error;	if(read(i, buf, sizeof(buf)) >= sizeof(buf))		goto error;	close(i);	p = buf;	if(rd_name(&p, timezone.stname))		goto error;	if(rd_long(&p, &timezone.stdiff))		goto error;	if(rd_name(&p, timezone.dlname))		goto error;	if(rd_long(&p, &timezone.dldiff))		goto error;	for(i=0; i<TZSIZE; i++) {		if(rd_long(&p, &timezone.dlpairs[i]))			goto error;		if(timezone.dlpairs[i] == 0)			return;	} error:	timezone.stdiff = 0;	strcpy(timezone.stname, "GMT");	timezone.dlpairs[0] = 0;} static intrd_name(char **f, char *p){	int c, i; 	for(;;) {		c = *(*f)++;		if(c != ' ' && c != '\n')			break;	}	for(i=0; i<3; i++) {		if(c == ' ' || c == '\n')			return 1;		*p++ = c;		c = *(*f)++;	}	if(c != ' ' && c != '\n')		return 1;	*p = 0;	return 0;} static intrd_long(char **f, long *p){	int c, s;	long l; 	s = 0;	for(;;) {		c = *(*f)++;		if(c == '-') {			s++;			continue;		}		if(c != ' ' && c != '\n')			break;	}	if(c == 0) {		*p = 0;		return 0;	}	l = 0;	for(;;) {		if(c == ' ' || c == '\n')			break;		if(c < '0' || c > '9')			return 1;		l = l*10 + c-'0';		c = *(*f)++;	}	if(s)		l = -l;	*p = l;	return 0;}