time.c

ucLinux is a very good embeded sytem. Most of company use this as their development OS.

	int fields[13];
	unsigned char mod;
	unsigned char code;

	i = 0;
	do {
		fields[i] = INT_MIN;
	} while (++i < 13);

	lvl = 0;
	p = format;

 LOOP:
	if (!*p) {
		if (lvl == 0) {			/* Done. */
			if (fields[6] == 7) { /* Cleanup for %u here since just once. */
				fields[6] = 0;	/* Don't use mod in case unset. */
			}

			i = 0;
			do {				/* Store the values into tm. */
				if (fields[i] != INT_MIN) {
					((int *) tm)[i] = fields[i];
				}
			} while (++i < 8);

			return (char *) buf; /* Success. */
		}
		p = stack[--lvl];
		goto LOOP;
	}

	if ((*p == '%') && (*++p != '%')) {
		mod = ILLEGAL_SPEC;
		if ((*p == 'O') || (*p == 'E')) { /* Modifier? */
			mod |= ((*p == 'O') ? NO_O_MOD : NO_E_MOD);
			++p;
		}

		if (!*p
			|| (((unsigned char)(((*p) | 0x20) - 'a')) >= 26)
			|| (((code = spec[(int)(*p - 'A')]) & mod) >= ILLEGAL_SPEC)
			) {
			return NULL;		/* Illegal spec. */
		}

		if ((code & MASK_SPEC) == STACKED_SPEC) {
			if (lvl == MAX_PUSH) {
				return NULL;	/* Stack full so treat as illegal spec. */
			}
			stack[lvl++] = ++p;
			if ((code &= 0xf) < 8) {
				p = ((const char *) spec) + STACKED_STRINGS_START + code;
				p += *((unsigned char *)p);
				goto LOOP;
			}

			p = ((const char *) spec) + STACKED_STRINGS_NL_ITEM_START
				+ (code & 7);
#ifdef ENABLE_ERA_CODE
			if ((mod & NO_E_MOD) /* Actually, this means E modifier present. */
				&& (*(o = __XL(nl_langinfo)(_NL_ITEM(LC_TIME,
											  (int)(((unsigned char *)p)[4]))
											__LOCALE_ARG
											)))
				) {
				p = o;
				goto LOOP;
			}
#endif
			p = __XL(nl_langinfo)(_NL_ITEM(LC_TIME,
										   (int)(*((unsigned char *)p)))
								  __LOCALE_ARG );
			goto LOOP;
		}

		++p;

		if ((code & MASK_SPEC) == STRING_SPEC) {
			code &= 0xf;
			j = spec[STRINGS_NL_ITEM_START + 3 + code];
			i = _NL_ITEM(LC_TIME, spec[STRINGS_NL_ITEM_START + code]);
			/* Go backwards to check full names before abreviations. */
			do {
				--j;
				o = __XL(nl_langinfo)(i+j   __LOCALE_ARG);
				if (!__XL(strncasecmp)(buf,o,strlen(o)   __LOCALE_ARG) && *o) {
					do {		/* Found a match. */
						++buf;
					} while (*++o);
					if (!code) { /* am/pm */
						fields[8] = j * 12;
						if (fields[9] >= 0) { /* We have a previous %I or %l. */
							fields[2] = fields[9] + fields[8];
						}
					} else {	/* day (4) or month (6) */
						fields[2 + (code << 1)]
							= j % (spec[STRINGS_NL_ITEM_START + 3 + code] >> 1);
					}
					goto LOOP;
				}
			} while (j);
			return NULL;		/* Failed to match. */
		}

		if ((code & MASK_SPEC) == CALC_SPEC) {
			if ((code &= 0xf) < 1) { /* s or z*/
				time_t t;

				o = (char *) buf;
				i = errno;
				__set_errno(0);
				if (!ISSPACE(*buf)) { /* Signal an error if whitespace. */
#ifdef TIME_T_IS_UNSIGNED
					t = __XL(strtoul)(buf, &o, 10   __LOCALE_ARG);
#else
					t = __XL(strtol)(buf, &o, 10   __LOCALE_ARG);
#endif
				}
				if ((o == buf) || errno) { /* Not a number or overflow. */
					return NULL;
				}
				__set_errno(i);	/* Restore errno. */
				buf = o;

				if (!code) {	/* s */
					localtime_r(&t, tm); /* TODO: check for failure? */
					i = 0;
					do {		/* Now copy values from tm to fields. */
						 fields[i] = ((int *) tm)[i];
					} while (++i < 8);
				}
			}
			/* TODO: glibc treats %Z as a nop.  For now, do the same. */
			goto LOOP;
		}

		assert((code & MASK_SPEC) == INT_SPEC);
		{
			register const unsigned char *x;
			code &= 0xf;
			x = spec + INT_FIELD_START + (code << 1);
			if ((j = x[1]) < 3) { /* upper bound (inclusive) */
				j = ((j==1) ? 366 : 9999);
			}
			i = -1;
			while (ISDIGIT(*buf)) {
				if (i < 0) {
					i = 0;
				}
				if ((i = 10*i + (*buf - '0')) > j) { /* Overflow. */
					return NULL;
				}
				++buf;
			}
			if (i < (*x & 1)) {	/* This catches no-digit case too. */
				return NULL;
			}
			if (*x & 2) {
				--i;
			}
			if (*x & 4) {
				i -= 1900;
			}

			if (*x == (9 << 3) + 1 + 0) { /* %I or %l */
				if (i == 12) {
					i = 0;
				}
				if (fields[8] >= 0) { /* We have a previous %p or %P. */
					fields[2] = i + fields[8];
				}
			}

			fields[(*x) >> 3] = i;

			if (((unsigned char)(*x - (10<< 3) + 0 + 0)) <= 8) { /* %C or %y */
				if ((j = fields[10]) < 0) {	/* No %C, so i must be %y data. */
					if (i <= 68) { /* Map [0-68] to 2000+i */
						i += 100;
					}
				} else {		/* Have %C data, but what about %y? */
					if ((i = fields[11]) < 0) {	/* No %y data. */
						i = 0;	/* Treat %y val as 0 following glibc's example. */
					}
					i += 100*(j - 19);
				}
				fields[5] = i;
			}
		}
		goto LOOP;
	} else if (ISSPACE(*p)) {
		++p;
		while (ISSPACE(*buf)) {
			++buf;
		}
		goto LOOP;
	} else if (*buf++ == *p++) {
		goto LOOP;
	}
	return NULL;
}

__XL_ALIAS(strptime)

#endif /* defined(__UCLIBC_HAS_XLOCALE__) && !defined(__UCLIBC_DO_XLOCALE) */

#endif
/**********************************************************************/
#ifdef L_time

#ifndef __BCC__
#error The uClibc version of time is in sysdeps/linux/common.
#endif

time_t time(register time_t *tloc)
{
	struct timeval tv;
	register struct timeval *p = &tv;

	gettimeofday(p, NULL);		/* This should never fail... */

	if (tloc) {
		*tloc = p->tv_sec;
	}

	return p->tv_sec;
}

#endif
/**********************************************************************/
#ifdef L_tzset

static const char vals[] = {
	'T', 'Z', 0,				/* 3 */
	'U', 'T', 'C', 0,			/* 4 */
	25, 60, 60, 1,				/* 4 */
	'.', 1,						/* M */
	5, '.', 1,
	6,  0,  0,					/* Note: overloaded for non-M non-J case... */
	0, 1, 0,					/* J */
	',', 'M',      '4', '.', '1', '.', '0',
	',', 'M', '1', '0', '.', '5', '.', '0', 0
};

#define TZ    vals
#define UTC   (vals + 3)
#define RANGE (vals + 7)
#define RULE  (vals + 11 - 1)
#define DEFAULT_RULES (vals + 22)

/* Initialize to UTC. */
int daylight = 0;
long timezone = 0;
char *tzname[2] = { (char *) UTC, (char *) (UTC-1) };

#ifdef __UCLIBC_HAS_THREADS__
pthread_mutex_t _time_tzlock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
#endif

rule_struct _time_tzinfo[2];

static const char *getoffset(register const char *e, long *pn)
{
	register const char *s = RANGE-1;
	long n;
	int f;

	n = 0;
	f = -1;
	do {
		++s;
		if (__isdigit_char(*e)) {
			f = *e++ - '0';
		}
		if (__isdigit_char(*e)) {
			f = 10 * f + (*e++ - '0');
		}
		if (((unsigned int)f) >= *s) {
			return NULL;
		}
		n = (*s) * n + f;
		f = 0;
		if (*e == ':') {
			++e;
			--f;
		}
	} while (*s > 1);

	*pn = n;
	return e;
}

static const char *getnumber(register const char *e, int *pn)
{
#ifdef __BCC__
	/* bcc can optimize the counter if it thinks it is a pointer... */
	register const char *n = (const char *) 3;
	int f;

	f = 0;
	while (n && __isdigit_char(*e)) {
		f = 10 * f + (*e++ - '0');
		--n;
	}

	*pn = f;
	return (n == (const char *) 3) ? NULL : e;
#else  /* __BCC__ */
	int n, f;

	n = 3;
	f = 0;
	while (n && __isdigit_char(*e)) {
		f = 10 * f + (*e++ - '0');
		--n;
	}

	*pn = f;
	return (n == 3) ? NULL : e;
#endif /* __BCC__ */
}


#ifdef __UCLIBC_MJN3_ONLY__
#warning CONSIDER: Should we preserve errno from open/read/close errors re TZ file?
#endif

#ifdef __UCLIBC_HAS_TZ_FILE__

#ifndef __UCLIBC_HAS_TZ_FILE_READ_MANY__
static int TZ_file_read;  		/* Let BSS initialization set this to 0. */
#endif /* __UCLIBC_HAS_TZ_FILE_READ_MANY__ */

static char *read_TZ_file(char *buf)
{
	int fd;
	ssize_t r;
	size_t todo;
	char *p = NULL;

	if ((fd = open(__UCLIBC_TZ_FILE_PATH__, O_RDONLY)) >= 0) {
		todo = TZ_BUFLEN;
		p = buf;
		do {
			if ((r = read(fd, p, todo)) < 0) {
				goto ERROR;
			}
			if (r == 0) {
				break;
			}
			p += r;
			todo -= r;
		} while (todo);

		if ((p > buf) && (p[-1] == '\n')) {	/* Must end with newline. */
			p[-1] = 0;
			p = buf;
#ifndef __UCLIBC_HAS_TZ_FILE_READ_MANY__
			++TZ_file_read;
#endif /* __UCLIBC_HAS_TZ_FILE_READ_MANY__ */
		} else {
		ERROR:
			p = NULL;
		}
		close(fd);
	}
	return p;
}

#endif /* __UCLIBC_HAS_TZ_FILE__ */

void tzset(void)
{
	register const char *e;
	register char *s;
	long off;
	short *p;
	rule_struct new_rules[2];
	int n, count, f;
	char c;
#ifdef __UCLIBC_HAS_TZ_FILE__
	char buf[TZ_BUFLEN];
#endif /* __UCLIBC_HAS_TZ_FILE__ */
#ifdef __UCLIBC_HAS_TZ_CACHING__
	static char oldval[TZ_BUFLEN]; /* BSS-zero'd. */
#endif /* __UCLIBC_HAS_TZ_CACHING__ */

	TZLOCK;

	e = getenv(TZ);				/* TZ env var always takes precedence. */

#if defined(__UCLIBC_HAS_TZ_FILE__) && !defined(__UCLIBC_HAS_TZ_FILE_READ_MANY__)
	/* Put this inside the lock to prevent the possiblity of two different
	 * timezones being used in a threaded app. */

	if (e != NULL) {
		TZ_file_read = 0;		/* Reset if the TZ env var is set. */
	} else if (TZ_file_read > 0) {
		goto FAST_DONE;
	}
#endif /* defined(__UCLIBC_HAS_TZ_FILE__) && !defined(__UCLIBC_HAS_TZ_FILE_READ_MANY__) */

	/* Warning!!!  Since uClibc doesn't do lib locking, the following is
	 * potentially unsafe in a multi-threaded program since it is remotely
	 * possible that another thread could call setenv() for TZ and overwrite
	 * the string being parsed.  So, don't do that... */

	if ((!e						/* TZ env var not set... */
#ifdef __UCLIBC_HAS_TZ_FILE__
		 && !(e = read_TZ_file(buf)) /* and no file or invalid file */
#endif /* __UCLIBC_HAS_TZ_FILE__ */
		 ) || !*e) {			/* or set to empty string. */
	ILLEGAL:					/* TODO: Clean up the following... */
#ifdef __UCLIBC_HAS_TZ_CACHING__
		*oldval = 0;			/* Set oldval to an empty string. */
#endif /* __UCLIBC_HAS_TZ_CACHING__ */
		memset(_time_tzinfo, 0, 2*sizeof(rule_struct));
		strcpy(_time_tzinfo[0].tzname, UTC);
		goto DONE;
	}

	if (*e == ':') {			/* Ignore leading ':'. */
		++e;
	}

#ifdef __UCLIBC_HAS_TZ_CACHING__
	if (strcmp(e, oldval) == 0) { /* Same string as last time... */
		goto FAST_DONE;			/* So nothing to do. */
	}
	/* Make a copy of the TZ env string.  It won't be nul-terminated if
	 * it is too long, but it that case it will be illegal and will be reset
	 * to the empty string anyway. */
	strncpy(oldval, e, TZ_BUFLEN);
#endif /* __UCLIBC_HAS_TZ_CACHING__ */
	
	count = 0;
	new_rules[1].tzname[0] = 0;
 LOOP:
	/* Get std or dst name. */
	c = 0;
	if (*e == '<') {
		++e;
		c = '>';
	}

	s = new_rules[count].tzname;
	n = 0;
	while (*e
		   && isascii(*e)		/* SUSv3 requires char in portable char set. */
		   && (isalpha(*e)
			   || (c && (isalnum(*e) || (*e == '+') || (*e == '-'))))
		   ) {
		*s++ = *e++;
		if (++n > TZNAME_MAX) {
			goto ILLEGAL;
		}
	}
	*s = 0;

	if ((n < 3)					/* Check for minimum length. */
		|| (c && (*e++ != c))	/* Match any quoting '<'. */
		) {
		goto ILLEGAL;
	}

	/* Get offset */
	s = (char *) e;
	if ((*e != '-') && (*e != '+')) {
		if (count && !__isdigit_char(*e)) {