From ccbd1d7dc5189f4637468a8136f672e60ee0e531 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Sun, 1 Nov 1992 05:44:29 +0000 Subject: Initial revision --- lib/strftime.c | 428 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 428 insertions(+) create mode 100644 lib/strftime.c (limited to 'lib/strftime.c') diff --git a/lib/strftime.c b/lib/strftime.c new file mode 100644 index 000000000..cc4953e68 --- /dev/null +++ b/lib/strftime.c @@ -0,0 +1,428 @@ +/* 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; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + +/* 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 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 */ + +#include +#if defined(TM_IN_SYS_TIME) || (!defined(HAVE_TM_ZONE) && !defined(HAVE_TZNAME)) +#include +#else +#include +#endif + +#if defined(HAVE_TZNAME) +extern char *tzname[2]; +#endif + +#if !__STDC__ +#define const +#endif + +/* Types of padding for numbers in date and time. */ +enum padding +{ + none, blank, zero +}; + +static char *days[] = +{ + "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday" +}; + +static char *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) (length + 1 <= max) && (string[length++] = (c)) + +/* Add a 2 digit number to STRING, padding if specified. + Return the number of characters added, up to MAX. */ + +static int +add_num2 (string, num, max, pad) + 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 (string, num, max, pad) + 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 (to, from, max) + char *to; + char *from; + int max; +{ + int i; + + for (i = 0; from[i] && i <= max; ++i) + to[i] = from[i]; + return i; +} + +/* Return the week in the year of the time in TM, with the weeks + starting on Sundays. */ + +static int +sun_week (tm) + 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 (tm) + 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 (tp) + 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 (string, max, format, tm) + 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': + 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; +} -- cgit v1.2.3-70-g09d2