/* strftime - custom formatting of date and/or time Copyright (C) 1989, 1991, 1992 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* Synched up with: FSF 19.30. */ /* Note: this version of strftime lacks locale support, but it is standalone. Performs `%' substitutions similar to those in printf. Except where noted, substituted fields have a fixed size; numeric fields are padded if necessary. Padding is with zeros by default; for fields that display a single number, padding can be changed or inhibited by following the `%' with one of the modifiers described below. Unknown field specifiers are copied as normal characters. All other characters are copied to the output without change. Supports a superset of the ANSI C field specifiers. Literal character fields: % % n newline t tab Numeric modifiers (a nonstandard extension): - do not pad the field _ pad the field with spaces Time fields: %H hour (00..23) %I hour (01..12) %k hour ( 0..23) %l hour ( 1..12) %M minute (00..59) %p locale's AM or PM %r time, 12-hour (hh:mm:ss [AP]M) %R time, 24-hour (hh:mm) %s time in seconds since 00:00:00, Jan 1, 1970 (a nonstandard extension) %S second (00..61) %T time, 24-hour (hh:mm:ss) %X locale's time representation (%H:%M:%S) %Z time zone (EDT), or nothing if no time zone is determinable Date fields: %a locale's abbreviated weekday name (Sun..Sat) %A locale's full weekday name, variable length (Sunday..Saturday) %b locale's abbreviated month name (Jan..Dec) %B locale's full month name, variable length (January..December) %c locale's date and time (Sat Nov 04 12:02:33 EST 1989) %C century (00..99) %d day of month (01..31) %e day of month ( 1..31) %D date (mm/dd/yy) %h same as %b %j day of year (001..366) %m month (01..12) %U week number of year with Sunday as first day of week (00..53) %w day of week (0..6) %W week number of year with Monday as first day of week (00..53) %x locale's date representation (mm/dd/yy) %y last two digits of year (00..99) %Y year (1970...) David MacKenzie */ #ifdef HAVE_CONFIG_H #include #include "lisp.h" #endif #include #include #if defined(TM_IN_SYS_TIME) || (!defined(HAVE_TM_ZONE) && !defined(HAVE_TZNAME)) #include #else #include #endif #ifndef STDC_HEADERS time_t mktime (); #endif #if defined(WIN32_NATIVE) || defined(CYGWIN) #include #else #if defined(HAVE_TZNAME) extern char *tzname[2]; #endif #endif /* WIN32_NATIVE */ #ifdef emacs #define strftime emacs_strftime #endif /* Types of padding for numbers in date and time. */ enum padding { none, blank, zero }; static char const* const days[] = { "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday" }; static char const * const months[] = { "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December" }; /* Add character C to STRING and increment LENGTH, unless LENGTH would exceed MAX. */ #define add_char(c) do \ { \ if (length + 1 <= max) \ string[length++] = (c); \ } while (0) /* Add a 2 digit number to STRING, padding if specified. Return the number of characters added, up to MAX. */ static int add_num2 (char *string, int num, int max, enum padding pad) { int top = num / 10; int length = 0; if (top == 0 && pad == blank) add_char (' '); else if (top != 0 || pad == zero) add_char (top + '0'); add_char (num % 10 + '0'); return length; } /* Add a 3 digit number to STRING, padding if specified. Return the number of characters added, up to MAX. */ static int add_num3 (char *string, int num, int max, enum padding pad) { int top = num / 100; int mid = (num - top * 100) / 10; int length = 0; if (top == 0 && pad == blank) add_char (' '); else if (top != 0 || pad == zero) add_char (top + '0'); if (mid == 0 && top == 0 && pad == blank) add_char (' '); else if (mid != 0 || top != 0 || pad == zero) add_char (mid + '0'); add_char (num % 10 + '0'); return length; } /* Like strncpy except return the number of characters copied. */ static int add_str (char *to, const char *from, int max) { int i; for (i = 0; from[i] && i <= max; ++i) to[i] = from[i]; return i; } static int add_num_time_t (char *string, int max, time_t num) { /* This buffer is large enough to hold the character representation (including the trailing NUL) of any unsigned decimal quantity whose binary representation fits in 128 bits. */ char buf[40]; int length; if (sizeof (num) > 16) ABORT (); sprintf (buf, "%lu", (unsigned long) num); length = add_str (string, buf, max); return length; } /* Return the week in the year of the time in TM, with the weeks starting on Sundays. */ static int sun_week (const struct tm *tm) { int dl; /* Set `dl' to the day in the year of the last day of the week previous to the one containing the day specified in TM. If the day specified in TM is in the first week of the year, `dl' will be negative or 0. Otherwise, calculate the number of complete weeks before our week (dl / 7) and add any partial week at the start of the year (dl % 7). */ dl = tm->tm_yday - tm->tm_wday; return dl <= 0 ? 0 : dl / 7 + (dl % 7 != 0); } /* Return the week in the year of the time in TM, with the weeks starting on Mondays. */ static int mon_week (const struct tm *tm) { int dl, wday; if (tm->tm_wday == 0) wday = 6; else wday = tm->tm_wday - 1; dl = tm->tm_yday - wday; return dl <= 0 ? 0 : dl / 7 + (dl % 7 != 0); } #if !defined(HAVE_TM_ZONE) && !defined(HAVE_TZNAME) char *zone_name (const struct tm *tp); char * zone_name (const struct tm *tp) { char *timezone (); struct timeval tv; struct timezone tz; gettimeofday (&tv, &tz); return timezone (tz.tz_minuteswest, tp->tm_isdst); } #endif /* Format the time given in TM according to FORMAT, and put the results in STRING. Return the number of characters (not including terminating null) that were put into STRING, or 0 if the length would have exceeded MAX. */ size_t strftime (char *string, size_t max, const char *format, const struct tm *tm); size_t strftime (char *string, size_t max, const char *format, const struct tm *tm) { enum padding pad; /* Type of padding to apply. */ size_t length = 0; /* Characters put in STRING so far. */ for (; *format && length < max; ++format) { if (*format != '%') add_char (*format); else { ++format; /* Modifiers: */ if (*format == '-') { pad = none; ++format; } else if (*format == '_') { pad = blank; ++format; } else pad = zero; switch (*format) { /* Literal character fields: */ case 0: case '%': add_char ('%'); break; case 'n': add_char ('\n'); break; case 't': add_char ('\t'); break; default: add_char (*format); break; /* Time fields: */ case 'H': case 'k': length += add_num2 (&string[length], tm->tm_hour, max - length, *format == 'H' ? pad : blank); break; case 'I': case 'l': { int hour12; if (tm->tm_hour == 0) hour12 = 12; else if (tm->tm_hour > 12) hour12 = tm->tm_hour - 12; else hour12 = tm->tm_hour; length += add_num2 (&string[length], hour12, max - length, *format == 'I' ? pad : blank); } break; case 'M': length += add_num2 (&string[length], tm->tm_min, max - length, pad); break; case 'p': if (tm->tm_hour < 12) add_char ('A'); else add_char ('P'); add_char ('M'); break; case 'r': length += strftime (&string[length], max - length, "%I:%M:%S %p", tm); break; case 'R': length += strftime (&string[length], max - length, "%H:%M", tm); break; case 's': { struct tm writable_tm; writable_tm = *tm; length += add_num_time_t (&string[length], max - length, mktime (&writable_tm)); } break; case 'S': length += add_num2 (&string[length], tm->tm_sec, max - length, pad); break; case 'T': length += strftime (&string[length], max - length, "%H:%M:%S", tm); break; case 'X': length += strftime (&string[length], max - length, "%H:%M:%S", tm); break; case 'Z': #ifdef HAVE_TM_ZONE length += add_str (&string[length], tm->tm_zone, max - length); #else #ifdef HAVE_TZNAME if (tm->tm_isdst && tzname[1] && *tzname[1]) length += add_str (&string[length], tzname[1], max - length); else length += add_str (&string[length], tzname[0], max - length); #else length += add_str (&string[length], zone_name (tm), max - length); #endif #endif break; /* Date fields: */ case 'a': add_char (days[tm->tm_wday][0]); add_char (days[tm->tm_wday][1]); add_char (days[tm->tm_wday][2]); break; case 'A': length += add_str (&string[length], days[tm->tm_wday], max - length); break; case 'b': case 'h': add_char (months[tm->tm_mon][0]); add_char (months[tm->tm_mon][1]); add_char (months[tm->tm_mon][2]); break; case 'B': length += add_str (&string[length], months[tm->tm_mon], max - length); break; case 'c': length += strftime (&string[length], max - length, "%a %b %d %H:%M:%S %Z %Y", tm); break; case 'C': length += add_num2 (&string[length], (tm->tm_year + 1900) / 100, max - length, pad); break; case 'd': length += add_num2 (&string[length], tm->tm_mday, max - length, pad); break; case 'e': length += add_num2 (&string[length], tm->tm_mday, max - length, blank); break; case 'D': length += strftime (&string[length], max - length, "%m/%d/%y", tm); break; case 'j': length += add_num3 (&string[length], tm->tm_yday + 1, max - length, pad); break; case 'm': length += add_num2 (&string[length], tm->tm_mon + 1, max - length, pad); break; case 'U': length += add_num2 (&string[length], sun_week (tm), max - length, pad); break; case 'w': add_char (tm->tm_wday + '0'); break; case 'W': length += add_num2 (&string[length], mon_week (tm), max - length, pad); break; case 'x': length += strftime (&string[length], max - length, "%m/%d/%y", tm); break; case 'y': length += add_num2 (&string[length], tm->tm_year % 100, max - length, pad); break; case 'Y': add_char ((tm->tm_year + 1900) / 1000 + '0'); length += add_num3 (&string[length], (1900 + tm->tm_year) % 1000, max - length, zero); break; } } } add_char (0); return length - 1; }