/* 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 ado@elsie.nci.nih.gov, * February 1991, May 1992 * Fixes from Tor Lillqvist tml@tik.vtt.fi, * May 1993 * Further fixes from ado@elsie.nci.nih.gov, * February 1994 * %z code from chip@chinacat.unicom.com, * 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 <akr@m17n.org> * 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 *);#endifextern 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;#  elseextern 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 intmin(int a, int b){	return (a < b ? a : b);}#undef max	/* also, just in case *//* max --- return maximum of two numbers */static inline intmax(int a, int b){	return (a > b ? a : b);}/* strftime --- produce formatted time */size_tstrftime(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;