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Diffstat (limited to 'strftime.c')
| -rw-r--r-- | strftime.c | 633 |
1 files changed, 633 insertions, 0 deletions
diff --git a/strftime.c b/strftime.c new file mode 100644 index 000000000000..e85589079172 --- /dev/null +++ b/strftime.c @@ -0,0 +1,633 @@ +/* Convert a broken-down timestamp to a string. */ + +/* Copyright 1989 The Regents of the University of California. + All rights reserved. + + Redistribution and use in source and binary forms, with or without + modification, are permitted provided that the following conditions + are met: + 1. Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. + 2. Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + 3. Neither the name of the University nor the names of its contributors + may be used to endorse or promote products derived from this software + without specific prior written permission. + + THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND + ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + SUCH DAMAGE. */ + +/* +** Based on the UCB version with the copyright notice appearing above. +** +** This is ANSIish only when "multibyte character == plain character". +*/ + +#include "private.h" + +#include <fcntl.h> +#include <locale.h> +#include <stdio.h> + +#ifndef DEPRECATE_TWO_DIGIT_YEARS +# define DEPRECATE_TWO_DIGIT_YEARS false +#endif + +struct lc_time_T { + const char * mon[MONSPERYEAR]; + const char * month[MONSPERYEAR]; + const char * wday[DAYSPERWEEK]; + const char * weekday[DAYSPERWEEK]; + const char * X_fmt; + const char * x_fmt; + const char * c_fmt; + const char * am; + const char * pm; + const char * date_fmt; +}; + +#define Locale (&C_time_locale) + +static const struct lc_time_T C_time_locale = { + { + "Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" + }, { + "January", "February", "March", "April", "May", "June", + "July", "August", "September", "October", "November", "December" + }, { + "Sun", "Mon", "Tue", "Wed", + "Thu", "Fri", "Sat" + }, { + "Sunday", "Monday", "Tuesday", "Wednesday", + "Thursday", "Friday", "Saturday" + }, + + /* X_fmt */ + "%H:%M:%S", + + /* + ** x_fmt + ** C99 and later require this format. + ** Using just numbers (as here) makes Quakers happier; + ** it's also compatible with SVR4. + */ + "%m/%d/%y", + + /* + ** c_fmt + ** C99 and later require this format. + ** Previously this code used "%D %X", but we now conform to C99. + ** Note that + ** "%a %b %d %H:%M:%S %Y" + ** is used by Solaris 2.3. + */ + "%a %b %e %T %Y", + + /* am */ + "AM", + + /* pm */ + "PM", + + /* date_fmt */ + "%a %b %e %H:%M:%S %Z %Y" +}; + +enum warn { IN_NONE, IN_SOME, IN_THIS, IN_ALL }; + +static char * _add(const char *, char *, const char *); +static char * _conv(int, const char *, char *, const char *); +static char * _fmt(const char *, const struct tm *, char *, const char *, + enum warn *); +static char * _yconv(int, int, bool, bool, char *, char const *); + +#ifndef YEAR_2000_NAME +#define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" +#endif /* !defined YEAR_2000_NAME */ + +#if HAVE_STRFTIME_L +size_t +strftime_l(char *s, size_t maxsize, char const *format, struct tm const *t, + locale_t locale) +{ + /* Just call strftime, as only the C locale is supported. */ + return strftime(s, maxsize, format, t); +} +#endif + +size_t +strftime(char *s, size_t maxsize, const char *format, const struct tm *t) +{ + char * p; + enum warn warn = IN_NONE; + + tzset(); + p = _fmt(format, t, s, s + maxsize, &warn); + if (DEPRECATE_TWO_DIGIT_YEARS + && warn != IN_NONE && getenv(YEAR_2000_NAME)) { + fprintf(stderr, "\n"); + fprintf(stderr, "strftime format \"%s\" ", format); + fprintf(stderr, "yields only two digits of years in "); + if (warn == IN_SOME) + fprintf(stderr, "some locales"); + else if (warn == IN_THIS) + fprintf(stderr, "the current locale"); + else fprintf(stderr, "all locales"); + fprintf(stderr, "\n"); + } + if (p == s + maxsize) + return 0; + *p = '\0'; + return p - s; +} + +static char * +_fmt(const char *format, const struct tm *t, char *pt, + const char *ptlim, enum warn *warnp) +{ + for ( ; *format; ++format) { + if (*format == '%') { +label: + switch (*++format) { + case '\0': + --format; + break; + case 'A': + pt = _add((t->tm_wday < 0 || + t->tm_wday >= DAYSPERWEEK) ? + "?" : Locale->weekday[t->tm_wday], + pt, ptlim); + continue; + case 'a': + pt = _add((t->tm_wday < 0 || + t->tm_wday >= DAYSPERWEEK) ? + "?" : Locale->wday[t->tm_wday], + pt, ptlim); + continue; + case 'B': + pt = _add((t->tm_mon < 0 || + t->tm_mon >= MONSPERYEAR) ? + "?" : Locale->month[t->tm_mon], + pt, ptlim); + continue; + case 'b': + case 'h': + pt = _add((t->tm_mon < 0 || + t->tm_mon >= MONSPERYEAR) ? + "?" : Locale->mon[t->tm_mon], + pt, ptlim); + continue; + case 'C': + /* + ** %C used to do a... + ** _fmt("%a %b %e %X %Y", t); + ** ...whereas now POSIX 1003.2 calls for + ** something completely different. + ** (ado, 1993-05-24) + */ + pt = _yconv(t->tm_year, TM_YEAR_BASE, + true, false, pt, ptlim); + continue; + case 'c': + { + enum warn warn2 = IN_SOME; + + pt = _fmt(Locale->c_fmt, t, pt, ptlim, &warn2); + if (warn2 == IN_ALL) + warn2 = IN_THIS; + if (warn2 > *warnp) + *warnp = warn2; + } + continue; + case 'D': + pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp); + continue; + case 'd': + pt = _conv(t->tm_mday, "%02d", pt, ptlim); + continue; + case 'E': + case 'O': + /* + ** Locale modifiers of C99 and later. + ** The sequences + ** %Ec %EC %Ex %EX %Ey %EY + ** %Od %oe %OH %OI %Om %OM + ** %OS %Ou %OU %OV %Ow %OW %Oy + ** are supposed to provide alternative + ** representations. + */ + goto label; + case 'e': + pt = _conv(t->tm_mday, "%2d", pt, ptlim); + continue; + case 'F': + pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp); + continue; + case 'H': + pt = _conv(t->tm_hour, "%02d", pt, ptlim); + continue; + case 'I': + pt = _conv((t->tm_hour % 12) ? + (t->tm_hour % 12) : 12, + "%02d", pt, ptlim); + continue; + case 'j': + pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim); + continue; + case 'k': + /* + ** This used to be... + ** _conv(t->tm_hour % 12 ? + ** t->tm_hour % 12 : 12, 2, ' '); + ** ...and has been changed to the below to + ** match SunOS 4.1.1 and Arnold Robbins' + ** strftime version 3.0. That is, "%k" and + ** "%l" have been swapped. + ** (ado, 1993-05-24) + */ + pt = _conv(t->tm_hour, "%2d", pt, ptlim); + continue; +#ifdef KITCHEN_SINK + case 'K': + /* + ** After all this time, still unclaimed! + */ + pt = _add("kitchen sink", pt, ptlim); + continue; +#endif /* defined KITCHEN_SINK */ + case 'l': + /* + ** This used to be... + ** _conv(t->tm_hour, 2, ' '); + ** ...and has been changed to the below to + ** match SunOS 4.1.1 and Arnold Robbin's + ** strftime version 3.0. That is, "%k" and + ** "%l" have been swapped. + ** (ado, 1993-05-24) + */ + pt = _conv((t->tm_hour % 12) ? + (t->tm_hour % 12) : 12, + "%2d", pt, ptlim); + continue; + case 'M': + pt = _conv(t->tm_min, "%02d", pt, ptlim); + continue; + case 'm': + pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim); + continue; + case 'n': + pt = _add("\n", pt, ptlim); + continue; + case 'p': + pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? + Locale->pm : + Locale->am, + pt, ptlim); + continue; + case 'R': + pt = _fmt("%H:%M", t, pt, ptlim, warnp); + continue; + case 'r': + pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp); + continue; + case 'S': + pt = _conv(t->tm_sec, "%02d", pt, ptlim); + continue; + case 's': + { + struct tm tm; + char buf[INT_STRLEN_MAXIMUM( + time_t) + 1]; + time_t mkt; + + tm = *t; + mkt = mktime(&tm); + if (TYPE_SIGNED(time_t)) + sprintf(buf, "%"PRIdMAX, + (intmax_t) mkt); + else sprintf(buf, "%"PRIuMAX, + (uintmax_t) mkt); + pt = _add(buf, pt, ptlim); + } + continue; + case 'T': + pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp); + continue; + case 't': + pt = _add("\t", pt, ptlim); + continue; + case 'U': + pt = _conv((t->tm_yday + DAYSPERWEEK - + t->tm_wday) / DAYSPERWEEK, + "%02d", pt, ptlim); + continue; + case 'u': + /* + ** From Arnold Robbins' strftime version 3.0: + ** "ISO 8601: Weekday as a decimal number + ** [1 (Monday) - 7]" + ** (ado, 1993-05-24) + */ + pt = _conv((t->tm_wday == 0) ? + DAYSPERWEEK : t->tm_wday, + "%d", pt, ptlim); + continue; + case 'V': /* ISO 8601 week number */ + case 'G': /* ISO 8601 year (four digits) */ + case 'g': /* ISO 8601 year (two digits) */ +/* +** From Arnold Robbins' strftime version 3.0: "the week number of the +** year (the first Monday as the first day of week 1) as a decimal number +** (01-53)." +** (ado, 1993-05-24) +** +** From <https://www.cl.cam.ac.uk/~mgk25/iso-time.html> by Markus Kuhn: +** "Week 01 of a year is per definition the first week which has the +** Thursday in this year, which is equivalent to the week which contains +** the fourth day of January. In other words, the first week of a new year +** is the week which has the majority of its days in the new year. Week 01 +** might also contain days from the previous year and the week before week +** 01 of a year is the last week (52 or 53) of the previous year even if +** it contains days from the new year. A week starts with Monday (day 1) +** and ends with Sunday (day 7). For example, the first week of the year +** 1997 lasts from 1996-12-30 to 1997-01-05..." +** (ado, 1996-01-02) +*/ + { + int year; + int base; + int yday; + int wday; + int w; + + year = t->tm_year; + base = TM_YEAR_BASE; + yday = t->tm_yday; + wday = t->tm_wday; + for ( ; ; ) { + int len; + int bot; + int top; + + len = isleap_sum(year, base) ? + DAYSPERLYEAR : + DAYSPERNYEAR; + /* + ** What yday (-3 ... 3) does + ** the ISO year begin on? + */ + bot = ((yday + 11 - wday) % + DAYSPERWEEK) - 3; + /* + ** What yday does the NEXT + ** ISO year begin on? + */ + top = bot - + (len % DAYSPERWEEK); + if (top < -3) + top += DAYSPERWEEK; + top += len; + if (yday >= top) { + ++base; + w = 1; + break; + } + if (yday >= bot) { + w = 1 + ((yday - bot) / + DAYSPERWEEK); + break; + } + --base; + yday += isleap_sum(year, base) ? + DAYSPERLYEAR : + DAYSPERNYEAR; + } +#ifdef XPG4_1994_04_09 + if ((w == 52 && + t->tm_mon == TM_JANUARY) || + (w == 1 && + t->tm_mon == TM_DECEMBER)) + w = 53; +#endif /* defined XPG4_1994_04_09 */ + if (*format == 'V') + pt = _conv(w, "%02d", + pt, ptlim); + else if (*format == 'g') { + *warnp = IN_ALL; + pt = _yconv(year, base, + false, true, + pt, ptlim); + } else pt = _yconv(year, base, + true, true, + pt, ptlim); + } + continue; + case 'v': + /* + ** From Arnold Robbins' strftime version 3.0: + ** "date as dd-bbb-YYYY" + ** (ado, 1993-05-24) + */ + pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp); + continue; + case 'W': + pt = _conv((t->tm_yday + DAYSPERWEEK - + (t->tm_wday ? + (t->tm_wday - 1) : + (DAYSPERWEEK - 1))) / DAYSPERWEEK, + "%02d", pt, ptlim); + continue; + case 'w': + pt = _conv(t->tm_wday, "%d", pt, ptlim); + continue; + case 'X': + pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp); + continue; + case 'x': + { + enum warn warn2 = IN_SOME; + + pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2); + if (warn2 == IN_ALL) + warn2 = IN_THIS; + if (warn2 > *warnp) + *warnp = warn2; + } + continue; + case 'y': + *warnp = IN_ALL; + pt = _yconv(t->tm_year, TM_YEAR_BASE, + false, true, + pt, ptlim); + continue; + case 'Y': + pt = _yconv(t->tm_year, TM_YEAR_BASE, + true, true, + pt, ptlim); + continue; + case 'Z': +#ifdef TM_ZONE + pt = _add(t->TM_ZONE, pt, ptlim); +#elif HAVE_TZNAME + if (t->tm_isdst >= 0) + pt = _add(tzname[t->tm_isdst != 0], + pt, ptlim); +#endif + /* + ** C99 and later say that %Z must be + ** replaced by the empty string if the + ** time zone is not determinable. + */ + continue; + case 'z': +#if defined TM_GMTOFF || USG_COMPAT || defined ALTZONE + { + long diff; + char const * sign; + bool negative; + +# ifdef TM_GMTOFF + diff = t->TM_GMTOFF; +# else + /* + ** C99 and later say that the UT offset must + ** be computed by looking only at + ** tm_isdst. This requirement is + ** incorrect, since it means the code + ** must rely on magic (in this case + ** altzone and timezone), and the + ** magic might not have the correct + ** offset. Doing things correctly is + ** tricky and requires disobeying the standard; + ** see GNU C strftime for details. + ** For now, punt and conform to the + ** standard, even though it's incorrect. + ** + ** C99 and later say that %z must be replaced by + ** the empty string if the time zone is not + ** determinable, so output nothing if the + ** appropriate variables are not available. + */ + if (t->tm_isdst < 0) + continue; + if (t->tm_isdst == 0) +# if USG_COMPAT + diff = -timezone; +# else + continue; +# endif + else +# ifdef ALTZONE + diff = -altzone; +# else + continue; +# endif +# endif + negative = diff < 0; + if (diff == 0) { +#ifdef TM_ZONE + negative = t->TM_ZONE[0] == '-'; +#else + negative = t->tm_isdst < 0; +# if HAVE_TZNAME + if (tzname[t->tm_isdst != 0][0] == '-') + negative = true; +# endif +#endif + } + if (negative) { + sign = "-"; + diff = -diff; + } else sign = "+"; + pt = _add(sign, pt, ptlim); + diff /= SECSPERMIN; + diff = (diff / MINSPERHOUR) * 100 + + (diff % MINSPERHOUR); + pt = _conv(diff, "%04d", pt, ptlim); + } +#endif + continue; + case '+': + pt = _fmt(Locale->date_fmt, t, pt, ptlim, + warnp); + continue; + case '%': + /* + ** X311J/88-090 (4.12.3.5): if conversion char is + ** undefined, behavior is undefined. Print out the + ** character itself as printf(3) also does. + */ + default: + break; + } + } + if (pt == ptlim) + break; + *pt++ = *format; + } + return pt; +} + +static char * +_conv(int n, const char *format, char *pt, const char *ptlim) +{ + char buf[INT_STRLEN_MAXIMUM(int) + 1]; + + sprintf(buf, format, n); + return _add(buf, pt, ptlim); +} + +static char * +_add(const char *str, char *pt, const char *ptlim) +{ + while (pt < ptlim && (*pt = *str++) != '\0') + ++pt; + return pt; +} + +/* +** POSIX and the C Standard are unclear or inconsistent about +** what %C and %y do if the year is negative or exceeds 9999. +** Use the convention that %C concatenated with %y yields the +** same output as %Y, and that %Y contains at least 4 bytes, +** with more only if necessary. +*/ + +static char * +_yconv(int a, int b, bool convert_top, bool convert_yy, + char *pt, const char *ptlim) +{ + register int lead; + register int trail; + +#define DIVISOR 100 + trail = a % DIVISOR + b % DIVISOR; + lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR; + trail %= DIVISOR; + if (trail < 0 && lead > 0) { + trail += DIVISOR; + --lead; + } else if (lead < 0 && trail > 0) { + trail -= DIVISOR; + ++lead; + } + if (convert_top) { + if (lead == 0 && trail < 0) + pt = _add("-0", pt, ptlim); + else pt = _conv(lead, "%02d", pt, ptlim); + } + if (convert_yy) + pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim); + return pt; +} |