strftime.c

android-w.song.android.widget

/* strftime - formatted time and date to a string */
/*
 * Modified slightly by Chet Ramey for inclusion in Bash
 */
/*
 * strftime.c
 *
 * Public-domain implementation of ISO C library routine.
 *
 * If you can't do prototypes, get GCC.
 *
 * The C99 standard now specifies just about all of the formats
 * that were additional in the earlier versions of this file.
 *
 * For extensions from SunOS, add SUNOS_EXT.
 * For extensions from HP/UX, add HPUX_EXT.
 * For VMS dates, add VMS_EXT.
 * For complete POSIX semantics, add POSIX_SEMANTICS.
 *
 * The code for %c, %x, and %X follows the C99 specification for
 * the "C" locale.
 *
 * This version ignores LOCALE information.
 * It also doesn't worry about multi-byte characters.
 * So there.
 *
 * Arnold Robbins
 * January, February, March, 1991
 * Updated March, April 1992
 * Updated April, 1993
 * Updated February, 1994
 * Updated May, 1994
 * Updated January, 1995
 * Updated September, 1995
 * Updated January, 1996
 * Updated July, 1997
 * Updated October, 1999
 * Updated September, 2000
 * Updated December, 2001
 * Updated January, 2011
 *
 * Fixes from [e-mail],
 * February 1991, May 1992
 * Fixes from Tor Lillqvist [e-mail],
 * May 1993
 * Further fixes from [e-mail],
 * February 1994
 * %z code from [e-mail],
 * Applied September 1995
 * %V code fixed (again) and %G, %g added,
 * January 1996
 * %v code fixed, better configuration,
 * July 1997
 * Moved to C99 specification.
 * September 2000
 * Fixes from Tanaka Akira <[e-mail]>
 * December 2001
 */
#include <config.h>

#include <stdio.h>
#include <ctype.h>
#include <time.h>

#if defined(TM_IN_SYS_TIME)
#include <sys/types.h>
#include <sys/time.h>
#endif

#include <stdlib.h>
#include <string.h>

/* defaults: season to taste */
#define SUNOS_EXT	1	/* stuff in SunOS strftime routine */
#define VMS_EXT		1	/* include %v for VMS date format */
#define HPUX_EXT	1	/* non-conflicting stuff in HP-UX date */
#define POSIX_SEMANTICS	1	/* call tzset() if TZ changes */

#undef strchr	/* avoid AIX weirdness */

#if defined (SHELL)
extern char *get_string_value (const char *);
#endif

extern void tzset(void);
static int weeknumber(const struct tm *timeptr, int firstweekday);
static int iso8601wknum(const struct tm *timeptr);

#ifndef inline
#ifdef __GNUC__
#define inline	__inline__
#else
#define inline	/**/
#endif
#endif

#define range(low, item, hi)	max(low, min(item, hi))

#if !defined(OS2) && !defined(MSDOS) && defined(HAVE_TZNAME)
extern char *tzname[2];
extern int daylight;
#if defined(SOLARIS) || defined(mips) || defined (M_UNIX)
extern long int timezone, altzone;
#else
#  if defined (HPUX)
extern long int timezone;
#  else
extern int timezone, altzone;
#  endif /* !HPUX */
#endif /* !SOLARIS && !mips && !M_UNIX */
#endif

#undef min	/* just in case */

/* format for %+ -- currently unused */
#ifndef NATIONAL_FORMAT
#define NATIONAL_FORMAT "%a %b %e %H:%M:%S %Z %Y"
#endif

/* min --- return minimum of two numbers */

static inline int
min(int a, int b)
{
	return (a < b ? a : b);
}

#undef max	/* also, just in case */

/* max --- return maximum of two numbers */

static inline int
max(int a, int b)
{
	return (a > b ? a : b);
}

/* strftime --- produce formatted time */

size_t
strftime(char *s, size_t maxsize, const char *format, const struct tm *timeptr)
{
	char *endp = s + maxsize;
	char *start = s;
	auto char tbuf[100];
	long off;
	int i, w;
	long y;
	static short first = 1;
#ifdef POSIX_SEMANTICS
	static char *savetz = NULL;
	static int savetzlen = 0;
	char *tz;
#endif /* POSIX_SEMANTICS */
#ifndef HAVE_TM_ZONE
#ifndef HAVE_TM_NAME
#ifndef HAVE_TZNAME
	extern char *timezone();
	struct timeval tv;
	struct timezone zone;
#endif /* HAVE_TZNAME */
#endif /* HAVE_TM_NAME */
#endif /* HAVE_TM_ZONE */

	/* various tables, useful in North America */
	static const char *days_a[] = {
		"Sun", "Mon", "Tue", "Wed",
		"Thu", "Fri", "Sat",
	};
	static const char *days_l[] = {
		"Sunday", "Monday", "Tuesday", "Wednesday",
		"Thursday", "Friday", "Saturday",
	};
	static const char *months_a[] = {
		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
	};
	static const char *months_l[] = {
		"January", "February", "March", "April",
		"May", "June", "July", "August", "September",
		"October", "November", "December",
	};
	static const char *ampm[] = { "AM", "PM", };

	if (s == NULL || format == NULL || timeptr == NULL || maxsize == 0)
		return 0;

	/* quick check if we even need to bother */
	if (strchr(format, '%') == NULL && strlen(format) + 1 >= maxsize)
		return 0;

#ifndef POSIX_SEMANTICS
	if (first) {
		tzset();
		first = 0;
	}
#else	/* POSIX_SEMANTICS */
#if defined (SHELL)
	tz = get_string_value ("TZ");
#else
	tz = getenv("TZ");
#endif
	if (first) {
		if (tz != NULL) {
			int tzlen = strlen(tz);

			savetz = (char *) malloc(tzlen + 1);
			if (savetz != NULL) {
				savetzlen = tzlen + 1;
				strcpy(savetz, tz);
			}
		}
		tzset();
		first = 0;
	}
	/* if we have a saved TZ, and it is different, recapture and reset */
	if (tz && savetz && (tz[0] != savetz[0] || strcmp(tz, savetz) != 0)) {
		i = strlen(tz) + 1;
		if (i > savetzlen) {
			savetz = (char *) realloc(savetz, i);
			if (savetz) {
				savetzlen = i;
				strcpy(savetz, tz);
			}
		} else
			strcpy(savetz, tz);
		tzset();
	}
#endif	/* POSIX_SEMANTICS */

	for (; *format && s < endp - 1; format++) {
		tbuf[0] = '\0';
		if (*format != '%') {
			*s++ = *format;
			continue;
		}
	again:
		switch (*++format) {
		case '\0':
			*s++ = '%';
			goto out;

		case '%':
			*s++ = '%';
			continue;

		case 'a':	/* abbreviated weekday name */
			if (timeptr->tm_wday < 0 || timeptr->tm_wday > 6)
				strcpy(tbuf, "?");
			else
				strcpy(tbuf, days_a[timeptr->tm_wday]);
			break;

		case 'A':	/* full weekday name */
			if (timeptr->tm_wday < 0 || timeptr->tm_wday > 6)
				strcpy(tbuf, "?");
			else
				strcpy(tbuf, days_l[timeptr->tm_wday]);
			break;

		case 'b':	/* abbreviated month name */
		short_month:
			if (timeptr->tm_mon < 0 || timeptr->tm_mon > 11)
				strcpy(tbuf, "?");
			else
				strcpy(tbuf, months_a[timeptr->tm_mon]);
			break;

		case 'B':	/* full month name */
			if (timeptr->tm_mon < 0 || timeptr->tm_mon > 11)
				strcpy(tbuf, "?");
			else
				strcpy(tbuf, months_l[timeptr->tm_mon]);
			break;

		case 'c':	/* appropriate date and time representation */
			/*
			 * This used to be:
			 *
			 * strftime(tbuf, sizeof tbuf, "%a %b %e %H:%M:%S %Y", timeptr);
			 *
			 * Now, per the ISO 1999 C standard, it this:
			 */
			strftime(tbuf, sizeof tbuf, "%A %B %d %T %Y", timeptr);
			break;

		case 'C':
		century:
			sprintf(tbuf, "%02ld", (timeptr->tm_year + 1900L) / 100);
			break;

		case 'd':	/* day of the month, 01 - 31 */
			i = range(1, timeptr->tm_mday, 31);
			sprintf(tbuf, "%02d", i);
			break;

		case 'D':	/* date as %m/%d/%y */
			strftime(tbuf, sizeof tbuf, "%m/%d/%y", timeptr);
			break;

		case 'e':	/* day of month, blank padded */
			sprintf(tbuf, "%2d", range(1, timeptr->tm_mday, 31));
			break;

		case 'E':
			/* POSIX (now C99) locale extensions, ignored for now */
			goto again;

		case 'F':	/* ISO 8601 date representation */
			strftime(tbuf, sizeof tbuf, "%Y-%m-%d", timeptr);
			break;

		case 'g':
		case 'G':
			/*
			 * Year of ISO week.
			 *
			 * If it's December but the ISO week number is one,
			 * that week is in next year.
			 * If it's January but the ISO week number is 52 or
			 * 53, that week is in last year.
			 * Otherwise, it's this year.
			 */
			w = iso8601wknum(timeptr);
			if (timeptr->tm_mon == 11 && w == 1)
				y = 1900L + timeptr->tm_year + 1;
			else if (timeptr->tm_mon == 0 && w >= 52)
				y = 1900L + timeptr->tm_year - 1;
			else
				y = 1900L + timeptr->tm_year;

			if (*format == 'G')
				sprintf(tbuf, "%ld", y);
			else
				sprintf(tbuf, "%02ld", y % 100);
			break;

		case 'h':	/* abbreviated month name */
			goto short_month;

		case 'H':	/* hour, 24-hour clock, 00 - 23 */
			i = range(0, timeptr->tm_hour, 23);
			sprintf(tbuf, "%02d", i);
			break;

		case 'I':	/* hour, 12-hour clock, 01 - 12 */
			i = range(0, timeptr->tm_hour, 23);
			if (i == 0)
				i = 12;
			else if (i > 12)
				i -= 12;
			sprintf(tbuf, "%02d", i);
			break;

		case 'j':	/* day of the year, 001 - 366 */
			sprintf(tbuf, "%03d", timeptr->tm_yday + 1);
			break;

		case 'm':	/* month, 01 - 12 */
			i = range(0, timeptr->tm_mon, 11);
			sprintf(tbuf, "%02d", i + 1);
			break;

		case 'M':	/* minute, 00 - 59 */
			i = range(0, timeptr->tm_min, 59);
			sprintf(tbuf, "%02d", i);
			break;

		case 'n':	/* same as \n */
			tbuf[0] = '\n';
			tbuf[1] = '\0';
			break;

		case 'O':
			/* POSIX (now C99) locale extensions, ignored for now */
			goto again;

		case 'p':	/* am or pm based on 12-hour clock */
			i = range(0, timeptr->tm_hour, 23);
			if (i < 12)
				strcpy(tbuf, ampm[0]);
			else
				strcpy(tbuf, ampm[1]);
			break;

		case 'r':	/* time as %I:%M:%S %p */
			strftime(tbuf, sizeof tbuf, "%I:%M:%S %p", timeptr);
			break;

		case 'R':	/* time as %H:%M */
			strftime(tbuf, sizeof tbuf, "%H:%M", timeptr);
			break;

#if defined(HAVE_MKTIME)
		case 's':	/* time as seconds since the Epoch */
		{
			struct tm non_const_timeptr;

			non_const_timeptr = *timeptr;
			sprintf(tbuf, "%ld", mktime(& non_const_timeptr));
			break;
		}
#endif /* defined(HAVE_MKTIME) */

		case 'S':	/* second, 00 - 60 */
			i = range(0, timeptr->tm_sec, 60);
			sprintf(tbuf, "%02d", i);
			break;

		case 't':	/* same as \t */
			tbuf[0] = '\t';
			tbuf[1] = '\0';
			break;

		case 'T':	/* time as %H:%M:%S */
		the_time:
			strftime(tbuf, sizeof tbuf, "%H:%M:%S", timeptr);
			break;

		case 'u':
		/* ISO 8601: Weekday as a decimal number [1 (Monday) - 7] */
			sprintf(tbuf, "%d", timeptr->tm_wday == 0 ? 7 :
					timeptr->tm_wday);
			break;

		case 'U':	/* week of year, Sunday is first day of week */
			sprintf(tbuf, "%02d", weeknumber(timeptr, 0));
			break;

		case 'V':	/* week of year according ISO 8601 */
			sprintf(tbuf, "%02d", iso8601wknum(timeptr));
			break;

		case 'w':	/* weekday, Sunday == 0, 0 - 6 */
			i = range(0, timeptr->tm_wday, 6);
			sprintf(tbuf, "%d", i);
			break;

		case 'W':	/* week of year, Monday is first day of week */
			sprintf(tbuf, "%02d", weeknumber(timeptr, 1));
			break;