/* * strftime.c * * Public-domain implementation of ANSI C library routine. * * It's written in old-style C for maximal portability. * However, since I'm used to prototypes, I've included them too. * * If you want stuff in the System V ascftime routine, add the SYSV_EXT define. * For extensions from SunOS, add SUNOS_EXT. * For stuff needed to implement the P1003.2 date command, add POSIX2_DATE. * For VMS dates, add VMS_EXT. * For complete POSIX semantics, add POSIX_SEMANTICS. * * The code for %c, %x, and %X is my best guess as to what's "appropriate". * This version ignores LOCALE information. * It also doesn't worry about multi-byte characters. * So there. * * This file is also shipped with GAWK (GNU Awk), gawk specific bits of * code are included if GAWK is defined. * * Arnold Robbins * January, February, March, 1991 * Updated March, April 1992 * Updated April, 1993 * Updated February, 1994 * Updated May, 1994 * * 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 */ #ifndef RUBY #include #include #include #include #endif #if defined(TM_IN_SYS_TIME) || ! defined(RUBY) #include #include #endif /* defaults: season to taste */ #define SYSV_EXT 1 /* stuff in System V ascftime routine */ #define SUNOS_EXT 1 /* stuff in SunOS strftime routine */ #define POSIX2_DATE 1 /* stuff in Posix 1003.2 date command */ #define VMS_EXT 1 /* include %v for VMS date format */ #ifndef RUBY #define POSIX_SEMANTICS 1 /* call tzset() if TZ changes */ #endif #if defined(POSIX2_DATE) #if ! defined(SYSV_EXT) #define SYSV_EXT 1 #endif #if ! defined(SUNOS_EXT) #define SUNOS_EXT 1 #endif #endif #if defined(POSIX2_DATE) #define adddecl(stuff) stuff #else #define adddecl(stuff) #endif #undef strchr /* avoid AIX weirdness */ #ifndef __STDC__ #define const /**/ extern void *malloc(); extern void *realloc(); extern void tzset(); extern char *strchr(); extern char *getenv(); static int weeknumber(); adddecl(static int iso8601wknum();) #else extern void *malloc(unsigned count); extern void *realloc(void *ptr, unsigned count); extern void tzset(void); extern char *strchr(const char *str, int ch); extern char *getenv(const char *v); static int weeknumber(const struct tm *timeptr, int firstweekday); adddecl(static int iso8601wknum(const struct tm *timeptr);) #endif #ifdef __GNUC__ #define inline __inline__ #else #define inline /**/ #endif #define range(low, item, hi) max(low, min(item, hi)) #if !defined(OS2) && !defined(MSDOS) && defined(HAVE_TZNAME) extern char *tzname[2]; # ifdef HAVE_DAYLIGHT extern int daylight; # endif #endif /* min --- return minimum of two numbers */ #ifndef __STDC__ static inline int min(a, b) int a, b; #else static inline int min(int a, int b) #endif { return (a < b ? a : b); } /* max --- return maximum of two numbers */ #ifndef __STDC__ static inline int max(a, b) int a, b; #else static inline int max(int a, int b) #endif { return (a > b ? a : b); } /* strftime --- produce formatted time */ #ifndef __STDC__ size_t strftime(s, maxsize, format, timeptr) char *s; size_t maxsize; const char *format; const struct tm *timeptr; #else size_t strftime(char *s, size_t maxsize, const char *format, const struct tm *timeptr) #endif { char *endp = s + maxsize; char *start = s; auto char tbuf[100]; int i; static short first = 1; #ifdef POSIX_SEMANTICS static char *savetz = NULL; static int savetzlen = 0; char *tz; #endif /* POSIX_SEMANTICS */ #ifndef HAVE_TM_ZONE extern char *timezone(); struct timeval tv; struct timezone zone; #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 */ tz = getenv("TZ"); 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; #ifdef SYSV_EXT case 'h': /* abbreviated month name */ #endif case 'b': /* abbreviated month name */ 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 */ sprintf(tbuf, "%s %s %2d %02d:%02d:%02d %d", days_a[range(0, timeptr->tm_wday, 6)], months_a[range(0, timeptr->tm_mon, 11)], range(1, timeptr->tm_mday, 31), range(0, timeptr->tm_hour, 23), range(0, timeptr->tm_min, 59), range(0, timeptr->tm_sec, 61), timeptr->tm_year + 1900); break; case 'd': /* day of the month, 01 - 31 */ i = range(1, timeptr->tm_mday, 31); sprintf(tbuf, "%02d", i); break; 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 '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 'S': /* second, 00 - 61 */ i = range(0, timeptr->tm_sec, 61); sprintf(tbuf, "%02d", i); break; case 'U': /* week of year, Sunday is first day of week */ sprintf(tbuf, "%02d", weeknumber(timeptr, 0)); 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; case 'x': /* appropriate date representation */ sprintf(tbuf, "%s %s %2d %d", days_a[range(0, timeptr->tm_wday, 6)], months_a[range(0, timeptr->tm_mon, 11)], range(1, timeptr->tm_mday, 31), timeptr->tm_year + 1900); break; case 'X': /* appropriate time representation */ sprintf(tbuf, "%02d:%02d:%02d", range(0, timeptr->tm_hour, 23), range(0, timeptr->tm_min, 59), range(0, timeptr->tm_sec, 61)); break; case 'y': /* year without a century, 00 - 99 */ i = timeptr->tm_year % 100; sprintf(tbuf, "%02d", i); break; case 'Y': /* year with century */ sprintf(tbuf, "%d", 1900 + timeptr->tm_year); break; case 'Z': /* time zone name or abbrevation */ #ifdef HAVE_TZNAME #ifdef HAVE_DAYLIGHT i = (daylight && timeptr->tm_isdst); /* 0 or 1 */ #else i = timeptr->tm_isdst; #endif strcpy(tbuf, tzname[i]); #else #ifdef HAVE_TM_ZONE strcpy(tbuf, timeptr->tm_zone); #else gettimeofday(& tv, & zone); strcpy(tbuf, timezone(zone.tz_minuteswest, timeptr->tm_isdst)); #endif #endif break; #ifdef SYSV_EXT case 'n': /* same as \n */ tbuf[0] = '\n'; tbuf[1] = '\0'; break; case 't': /* same as \t */ tbuf[0] = '\t'; tbuf[1] = '\0'; 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 '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; case 'T': /* time as %H:%M:%S */ strftime(tbuf, sizeof tbuf, "%H:%M:%S", timeptr); break; #endif #ifdef SUNOS_EXT case 'k': /* hour, 24-hour clock, blank pad */ sprintf(tbuf, "%2d", range(0, timeptr->tm_hour, 23)); break; case 'l': /* hour, 12-hour clock, 1 - 12, blank pad */ i = range(0, timeptr->tm_hour, 23); if (i == 0) i = 12; else if (i > 12) i -= 12; sprintf(tbuf, "%2d", i); break; #endif #ifdef VMS_EXT case 'v': /* date as dd-bbb-YYYY */ sprintf(tbuf, "%02d-%3.3s-%4d", range(1, timeptr->tm_mday, 31), months_a[range(0, timeptr->tm_mon, 11)], timeptr->tm_year + 1900); for (i = 3; i < 6; i++) if (islower(tbuf[i])) tbuf[i] = toupper(tbuf[i]); break; #endif #ifdef POSIX2_DATE case 'C': sprintf(tbuf, "%02d", (timeptr->tm_year + 1900) / 100); break; case 'E': case 'O': /* POSIX locale extensions, ignored for now */ goto again; case 'V': /* week of year according ISO 8601 */ #if defined(GAWK) && defined(VMS_EXT) { extern int do_lint; extern void warning(); static int warned = 0; if (! warned && do_lint) { warned = 1; warning( "conversion %%V added in P1003.2; for VMS style date, use %%v"); } } #endif sprintf(tbuf, "%02d", iso8601wknum(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; #endif /* POSIX2_DATE */ default: tbuf[0] = '%'; tbuf[1] = *format; tbuf[2] = '\0'; break; } i = strlen(tbuf); if (i) { if (s + i < endp - 1) { strcpy(s, tbuf); s += i; } else return 0; } } out: if (s < endp && *format == '\0') { *s = '\0'; return (s - start); } else return 0; } /* isleap --- is a year a leap year? */ #ifndef __STDC__ static int isleap(year) int year; #else static int isleap(int year) #endif { return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0); } #ifdef POSIX2_DATE /* iso8601wknum --- compute week number according to ISO 8601 */ #ifndef __STDC__ static int iso8601wknum(timeptr) const struct tm *timeptr; #else static int iso8601wknum(const struct tm *timeptr) #endif { /* * From 1003.2: * If the week (Monday to Sunday) containing January 1 * has four or more days in the new year, then it is week 1; * otherwise it is the highest numbered week of the previous * (52 or 53) year, and the next week is week 1. * * ADR: This means if Jan 1 was Monday through Thursday, * it was week 1, otherwise week 52 or 53. * * XPG4 erroneously included POSIX.2 rationale text in the * main body of the standard. Thus it requires week 53. */ int weeknum, jan1day, diff; /* get week number, Monday as first day of the week */ weeknum = weeknumber(timeptr, 1); /* * With thanks and tip of the hatlo to tml@tik.vtt.fi * * What day of the week does January 1 fall on? * We know that * (timeptr->tm_yday - jan1.tm_yday) MOD 7 == * (timeptr->tm_wday - jan1.tm_wday) MOD 7 * and that * jan1.tm_yday == 0 * and that * timeptr->tm_wday MOD 7 == timeptr->tm_wday * from which it follows that. . . */ jan1day = timeptr->tm_wday - (timeptr->tm_yday % 7); if (jan1day < 0) jan1day += 7; /* * If Jan 1 was a Monday through Thursday, it was in * week 1. Otherwise it was last year's highest week, which is * this year's week 0. * * What does that mean? * If Jan 1 was Monday, the week number is exactly right, it can * never be 0. * If it was Tuesday through Thursday, the weeknumber is one * less than it should be, so we add one. * Otherwise, Friday, Saturday or Sunday, the week number is * OK, but if it is 0, it needs to be 52 or 53. */ switch (jan1day) { case 1: /* Monday */ break; case 2: /* Tuesday */ case 3: /* Wednedsday */ case 4: /* Thursday */ weeknum++; break; case 5: /* Friday */ case 6: /* Saturday */ case 0: /* Sunday */ if (weeknum == 0) { #ifdef USE_BROKEN_XPG4 /* XPG4 (as of March 1994) says 53 unconditionally */ weeknum = 53; #else /* get week number of last week of last year */ struct tm dec31ly; /* 12/31 last year */ dec31ly = *timeptr; dec31ly.tm_year--; dec31ly.tm_mon = 11; dec31ly.tm_mday = 31; dec31ly.tm_wday = (jan1day == 0) ? 6 : jan1day - 1; dec31ly.tm_yday = 364 + isleap(dec31ly.tm_year + 1900); weeknum = iso8601wknum(& dec31ly); #endif } break; } return weeknum; } #endif /* weeknumber --- figure how many weeks into the year */ /* With thanks and tip of the hatlo to ado@elsie.nci.nih.gov */ #ifndef __STDC__ static int weeknumber(timeptr, firstweekday) const struct tm *timeptr; int firstweekday; #else static int weeknumber(const struct tm *timeptr, int firstweekday) #endif { int wday = timeptr->tm_wday; int ret; if (firstweekday == 1) { if (wday == 0) /* sunday */ wday = 6; else wday--; } ret = ((timeptr->tm_yday + 7 - wday) / 7); if (ret < 0) ret = 0; return ret; } #if 0 /* ADR --- I'm loathe to mess with ado's code ... */ Date: Wed, 24 Apr 91 20:54:08 MDT From: Michal Jaegermann To: arnold@audiofax.com Hi Arnold, in a process of fixing of strftime() in libraries on Atari ST I grabbed some pieces of code from your own strftime. When doing that it came to mind that your weeknumber() function compiles a little bit nicer in the following form: /* * firstweekday is 0 if starting in Sunday, non-zero if in Monday */ { return (timeptr->tm_yday - timeptr->tm_wday + (firstweekday ? (timeptr->tm_wday ? 8 : 1) : 7)) / 7; } How nicer it depends on a compiler, of course, but always a tiny bit. Cheers, Michal ntomczak@vm.ucs.ualberta.ca #endif #ifdef TEST_STRFTIME /* * NAME: * tst * * SYNOPSIS: * tst * * DESCRIPTION: * "tst" is a test driver for the function "strftime". * * OPTIONS: * None. * * AUTHOR: * Karl Vogel * Control Data Systems, Inc. * vogelke@c-17igp.wpafb.af.mil * * BUGS: * None noticed yet. * * COMPILE: * cc -o tst -DTEST_STRFTIME strftime.c */ /* ADR: I reformatted this to my liking, and deleted some unneeded code. */ #ifndef NULL #include #endif #include #include #define MAXTIME 132 /* * Array of time formats. */ static char *array[] = { "(%%A) full weekday name, var length (Sunday..Saturday) %A", "(%%B) full month name, var length (January..December) %B", "(%%C) Century %C", "(%%D) date (%%m/%%d/%%y) %D", "(%%E) Locale extensions (ignored) %E", "(%%H) hour (24-hour clock, 00..23) %H", "(%%I) hour (12-hour clock, 01..12) %I", "(%%M) minute (00..59) %M", "(%%O) Locale extensions (ignored) %O", "(%%R) time, 24-hour (%%H:%%M) %R", "(%%S) second (00..61) %S", "(%%T) time, 24-hour (%%H:%%M:%%S) %T", "(%%U) week of year, Sunday as first day of week (00..53) %U", "(%%V) week of year according to ISO 8601 %V", "(%%W) week of year, Monday as first day of week (00..53) %W", "(%%X) appropriate locale time representation (%H:%M:%S) %X", "(%%Y) year with century (1970...) %Y", "(%%Z) timezone (EDT), or blank if timezone not determinable %Z", "(%%a) locale's abbreviated weekday name (Sun..Sat) %a", "(%%b) locale's abbreviated month name (Jan..Dec) %b", "(%%c) full date (Sat Nov 4 12:02:33 1989)%n%t%t%t %c", "(%%d) day of the month (01..31) %d", "(%%e) day of the month, blank-padded ( 1..31) %e", "(%%h) should be same as (%%b) %h", "(%%j) day of the year (001..366) %j", "(%%k) hour, 24-hour clock, blank pad ( 0..23) %k", "(%%l) hour, 12-hour clock, blank pad ( 0..12) %l", "(%%m) month (01..12) %m", "(%%p) locale's AM or PM based on 12-hour clock %p", "(%%r) time, 12-hour (same as %%I:%%M:%%S %%p) %r", "(%%u) ISO 8601: Weekday as decimal number [1 (Monday) - 7] %u", "(%%v) VAX date (dd-bbb-YYYY) %v", "(%%w) day of week (0..6, Sunday == 0) %w", "(%%x) appropriate locale date representation %x", "(%%y) last two digits of year (00..99) %y", (char *) NULL }; /* main routine. */ int main(argc, argv) int argc; char **argv; { long time(); char *next; char string[MAXTIME]; int k; int length; struct tm *tm; long clock; /* Call the function. */ clock = time((long *) 0); tm = localtime(&clock); for (k = 0; next = array[k]; k++) { length = strftime(string, MAXTIME, next, tm); printf("%s\n", string); } exit(0); } #endif /* TEST_STRFTIME */