+/*
+ * strftime.c
+ *
+ * Public-domain relatively quick-and-dirty implementation 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 extensions from SunOS, add SUNOS_EXT.
+ * For stuff needed to implement the P1003.2 date command, add POSIX2_DATE.
+ * 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
+ *
+ * Fixes from ado@elsie.nci.nih.gov
+ * February 1991, May 1992
+ * Fixes from Tor Lillqvist tor@tik.vtt.fi
+ * May, 1993
+ */
+
+#ifndef GAWK
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+#include <time.h>
+#include <sys/types.h>
+#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 GAWK
+#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(MSDOS) && !defined(TZNAME_MISSING)
+extern char *tzname[2];
+extern int daylight;
+#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;
+ 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 */
+
+ /* 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;
+
+#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, "%d", 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, "%d", 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, "%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", 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, "%2d-%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 P1003.2/11.3; for VMS style date, use %%v");
+ }
+ }
+#endif
+ sprintf(tbuf, "%d", 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;
+}
+
+#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 D11.3:
+ * 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 week 53 of the previous year, and the
+ * next week is week 1.
+ *
+ * ADR: This means if Jan 1 was Monday through Thursday,
+ * it was week 1, otherwise week 53.
+ */
+
+ int simple_wknum, jan1day, diff, ret;
+
+ /* get week number, Monday as first day of the week */
+ simple_wknum = weeknumber(timeptr, 1) + 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 week 53, which is
+ * this year's week 0.
+ */
+ if (jan1day >= 1 && jan1day <= 4)
+ diff = 0;
+ else
+ diff = 1;
+ ret = simple_wknum - diff;
+ if (ret == 0) /* we're in the first week of the year */
+ ret = 53;
+ return ret;
+}
+#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
+{
+ 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 <audfax!emory!vm.ucs.UAlberta.CA!NTOMCZAK>
+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 <stdio.h>
+#endif
+#include <sys/time.h>
+#include <string.h>
+
+#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 */
projects / unix-history / commitdiff