/* * strftime.c * * Public-domain relatively quick-and-dirty implemenation of * ANSI library routine for System V Unix systems. * * 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 stuff needed to implement the P1003.2 date command, add POSIX2_DATE. * * 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. * * Arnold Robbins * January, February, March, 1991 * * Fixes from ado@elsie.nci.nih.gov * February 1991 */ #if 0 #include #include #include #include #include #endif #ifndef __STDC__ #define const /**/ #endif #ifndef __STDC__ extern void tzset(); extern char *strchr(); static int weeknumber(); #else extern void tzset(void); extern char *strchr(const char *str, int ch); static int weeknumber(const struct tm *timeptr, int firstweekday); #endif #if !defined(MSDOS) && !defined(TZNAME_MISSING) extern char *tzname[2]; extern int daylight; #endif #define SYSV_EXT 1 /* stuff in System V ascftime routine */ #define POSIX2_DATE 1 /* stuff in Posix 1003.2 date command */ #define VMS_EXT 1 /* include %V for VMS date format */ #if defined(POSIX2_DATE) && ! defined(SYSV_EXT) #define SYSV_EXT 1 #endif /* 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; char tbuf[100]; int i; static short first = 1; /* various tables, useful in North America */ static char *days_a[] = { "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", }; static char *days_l[] = { "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", }; static char *months_a[] = { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec", }; static char *months_l[] = { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December", }; static char *ampm[] = { "AM", "PM", }; if (s == NULL || format == NULL || timeptr == NULL || maxsize == 0) return 0; if (strchr(format, '%') == NULL && strlen(format) + 1 >= maxsize) return 0; if (first) { tzset(); first = 0; } 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[timeptr->tm_wday], months_a[timeptr->tm_mon], timeptr->tm_mday, timeptr->tm_hour, timeptr->tm_min, timeptr->tm_sec, timeptr->tm_year + 1900); break; case 'd': /* day of the month, 01 - 31 */ sprintf(tbuf, "%02d", timeptr->tm_mday); break; case 'H': /* hour, 24-hour clock, 00 - 23 */ sprintf(tbuf, "%02d", timeptr->tm_hour); break; case 'I': /* hour, 12-hour clock, 01 - 12 */ i = timeptr->tm_hour; 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 */ sprintf(tbuf, "%02d", timeptr->tm_mon + 1); break; case 'M': /* minute, 00 - 59 */ sprintf(tbuf, "%02d", timeptr->tm_min); break; case 'p': /* am or pm based on 12-hour clock */ if (timeptr->tm_hour < 12) strcpy(tbuf, ampm[0]); else strcpy(tbuf, ampm[1]); break; case 'S': /* second, 00 - 61 */ sprintf(tbuf, "%02d", timeptr->tm_sec); break; case 'U': /* week of year, Sunday is first day of week */ sprintf(tbuf, "%d", weeknumber(timeptr, 0)); break; case 'w': /* weekday, Sunday == 0, 0 - 6 */ sprintf(tbuf, "%d", timeptr->tm_wday); break; case 'W': /* week of year, Monday is first day of week */ sprintf(tbuf, "%d", weeknumber(timeptr, 1)); break; case 'x': /* appropriate date representation */ sprintf(tbuf, "%s %s %2d %d", days_a[timeptr->tm_wday], months_a[timeptr->tm_mon], timeptr->tm_mday, timeptr->tm_year + 1900); break; case 'X': /* appropriate time representation */ sprintf(tbuf, "%02d:%02d:%02d", timeptr->tm_hour, timeptr->tm_min, timeptr->tm_sec); break; case 'y': /* year without a century, 00 - 99 */ i = timeptr->tm_year % 100; sprintf(tbuf, "%d", i); break; case 'Y': /* year with century */ sprintf(tbuf, "%d", 1900 + timeptr->tm_year); break; case 'Z': /* time zone name or abbrevation */ i = 0; if ( #ifndef TZNAME_MISSING daylight && #endif timeptr->tm_isdst) i = 1; #ifdef TZNAME_MISSING strcpy(tbuf, timeptr->tm_zone); #else strcpy(tbuf, tzname[i]); #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", timeptr->tm_mday); 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 VMS_EXT case 'V': /* date as dd-bbb-YYYY */ sprintf(tbuf, "%2d-%3.3s-%4d", timeptr->tm_mday, months_a[timeptr->tm_mon], 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; #endif 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; } /* 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 { if (firstweekday == 0) return (timeptr->tm_yday + 7 - timeptr->tm_wday) / 7; else return (timeptr->tm_yday + 7 - (timeptr->tm_wday ? (timeptr->tm_wday - 1) : 6)) / 7; } #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