Source Code 1992 March/Source_Code_CD-ROM_Walnut_Creek_March_1992.iso/usenet/compsrcs/unix/volume06/datedi.ffs

Text File | 1988-09-11 | 24.6 KB | 978 lines

Subject: v06i012:  patches for date to use elsie!ado's localtime (datediffs)
Newsgroups: mod.sources
Approved:  [e-mail]

Submitted by: seismo!munnari!kre (Robert Elz)
Mod.sources: Volume 6, Issue 12
Archive-name: datediffs

This shell archive (below the line) contains diffs for various
versions of date.c to make them compatible with Arthur Olson's
modified localtime(3).  See the READ_ME for more details.

: ---------------------------------------- cut here

echo x - "READ_ME" 2>&1
sed "s/^X//" >"READ_ME" <<'!The!End!'
XThis posting contains diffs for 4 popular versions of "date.c"
Xto enable it to work correctly with Arthur Olson's posted
Xmodifications to localtime().  (in mod.sources, in March 86).
X
XAlmost no programs need to be modified to use that localtime,
Xhowever "date" is one of those that do (as it "knew" that daylight
Xsaving means 1 hour added on, and nothing else, and it used a
Xrather crude mechanism to correct for the local timezone when
Xsetting the date).
X
XThere are 3 changes of substance (and a few minor cleanups).
X
X1) If the TZ environment variable is set to something that doesn't
Xmake sense, prevent the date from being set (its likely to end up
Xbeing not quite what was intended).
X
X2) Correct the time given properly, where its given in local time
X(in Sys V date there's no alternative).  Handle all variations of
Xdaylight saving, etc, that Arthur Olson's localtime can handle,
Xand that's practically everything.
X
X3) Print the time-zone name that the new localtime returns (in
Xthe global tz_abbr), rather than using the old ways of obtaining
Xtimezone names.
X
XAssumption: before these diffs will be useful, you must have installed
Xthe new localtime() in libc.  To do that you have to merge your
Xcurrent libc/ctime.c with the new one, changing the name of
Xnewlocaltime() to localtime() as you do it.  This is not particularly
Xdifficult.  You should compile it so that TZDIR is /etc/tzdir.
X
XProcedure: Select one of the following 4 diffs files.  If you are
Xa BSD 4.2 4.3 beta or 4.3 site take diffs.4.2, diffs.4.3beta, or
Xdiffs.4.3 respectively.  AT&T system sites should take diffs.SysV.
XV7 and BSD4.1 are on their own, sorry.  If you look at all four diffs
Xfiles you will see how similar they are, you shouldn't find it difficult
Xto install in any other version of date.  In particular, the major piece
Xof code is identical (modulo indentation) in all of these versions.
X
XThen use "patch" to apply the diffs as
X
X    cp /..../date.c .
X    chmod +w date.c
X    patch date.c < diffs.XXX
X
XThen check what was produced, make sure that it all makes sense.
XCompile & install the modified "date".
X
XRobert Elz        [e-mail]
X            seismo!munnari!kre
!The!End!

echo x - "diffs.4.2" 2>&1
sed "s/^X//" >"diffs.4.2" <<'!The!End!'
X*** date.c.4.2    Mon Apr 28 02:32:47 1986
X--- date.c.4.2.new    Mon Apr 28 02:33:37 1986
X***************
X*** 12,18
X  #define WTMP "/usr/adm/wtmp"
X
X  struct    timeval tv;
X- struct    timezone tz;
X  char    *ap, *ep, *sp;
X  int    uflag;
X
X
X--- 12,17 -----
X  #define WTMP "/usr/adm/wtmp"
X
X  struct    timeval tv;
X  char    *ap, *ep, *sp;
X  int    uflag;
X
X***************
X*** 16,22
X  char    *ap, *ep, *sp;
X  int    uflag;
X
X- char    *timezone();
X  static    int    dmsize[12] =
X      { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
X  static char *usage = "usage: date [-u] [yymmddhhmm[.ss]]\n";
X
X--- 15,20 -----
X  char    *ap, *ep, *sp;
X  int    uflag;
X
X  static    int    dmsize[12] =
X      { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
X  static char *usage = "usage: date [-u] [yymmddhhmm[.ss]]\n";
X***************
X*** 26,31
X      { "{", "", "", 0 }
X  };
X
X  char    *ctime();
X  char    *asctime();
X  struct    tm *localtime();
X
X--- 24,30 -----
X      { "{", "", "", 0 }
X  };
X
X+ char    *getenv();
X  char    *ctime();
X  char    *asctime();
X  struct    tm *localtime();
X***************
X*** 30,35
X  char    *asctime();
X  struct    tm *localtime();
X  struct    tm *gmtime();
X
X  main(argc, argv)
X      int argc;
X
X--- 29,35 -----
X  char    *asctime();
X  struct    tm *localtime();
X  struct    tm *gmtime();
X+ extern char *tz_abbr;
X
X  main(argc, argv)
X      int argc;
X***************
X*** 39,45
X      int wf, rc;
X
X      rc = 0;
X!     gettimeofday(&tv, &tz);
X      if (argc > 1 && strcmp(argv[1], "-u") == 0) {
X          argc--;
X          argv++;
X
X--- 39,45 -----
X      int wf, rc;
X
X      rc = 0;
X!     gettimeofday(&tv, (struct timezone *)0);
X      if (argc > 1 && strcmp(argv[1], "-u") == 0) {
X          argc--;
X          argv++;
X***************
X*** 46,51
X          uflag++;
X      }
X      if (argc > 1) {
X          ap = argv[1];
X          wtmp[0].ut_time = tv.tv_sec;
X          if (gtime()) {
X
X--- 46,56 -----
X          uflag++;
X      }
X      if (argc > 1) {
X+         if (settz(ap = getenv("TZ")) < 0) {
X+             fprintf(stderr, "Unknown timezone \"%s\"\n",
X+                 ap ? ap : "null");
X+             exit(1);
X+         }
X          ap = argv[1];
X          wtmp[0].ut_time = tv.tv_sec;
X          if (gtime()) {
X***************
X*** 54,63
X          }
X          /* convert to GMT assuming local time */
X          if (uflag == 0) {
X!             tv.tv_sec += (long)tz.tz_minuteswest*60;
X!             /* now fix up local daylight time */
X!             if (localtime(&tv.tv_sec)->tm_isdst)
X!                 tv.tv_sec -= 60*60;
X          }
X          tv.tv_sec = tv.tv_sec;
X          if (settimeofday(&tv, (struct timezone *)0) < 0) {
X
X--- 59,119 -----
X          }
X          /* convert to GMT assuming local time */
X          if (uflag == 0) {
X!             /*
X!              * Do this by determining what the given time
X!              * is when converted to local time, and when
X!              * converted to GMT and taking the difference.
X!              * This works correctly regardless of whether
X!              * local time is DST or not.
X!              * The loop usually runs twice, once to correct the
X!              * time, and once to check the correction was accurate.
X!              * An extra iteration can be caused by setting the time
X!              * just about when DST turns on or off.
X!              * If we iterate more than a couple of times, then
X!              * the idiot root moron has asked to set the time to
X!              * something in the "dead" zone where DST has just
X!              * turned on, and the times don't exist!
X!              * The ugly "if" statements are to handle wierd cases
X!              * that arise setting the time just about midnight on
X!              * Jan 1 after a year that was a leap year.
X!              * How close to midnight it has to be depends on how
X!              * close to Greenwich you are, whether before or after
X!              * midnight depends on whether you are East or West.
X!              */
X!             struct tm gmt;
X!             struct tm local;
X!             register long diff;
X!             register int iters = 0;
X!
X!             gmt = *gmtime(&tv.tv_sec);
X!             do {
X! #define    isleap(yr)    ((yr) % 4 == 0 && ((yr) % 100 != 0 || (yr) % 400 == 0))
X!                 local = *localtime(&tv.tv_sec);
X!                 diff = gmt.tm_year - local.tm_year;
X!                 diff *= 365;
X!                 if (gmt.tm_year > local.tm_year) {
X!                     if (isleap(local.tm_year))
X!                         diff++;
X!                 } else if (local.tm_year > gmt.tm_year) {
X!                     if (isleap(gmt.tm_year))
X!                         diff--;
X!                 }
X!                 diff += gmt.tm_yday - local.tm_yday;
X!                 diff *= 24;
X!                 diff += gmt.tm_hour - local.tm_hour;
X!                 diff *= 60;
X!                 diff += gmt.tm_min - local.tm_min;
X!                 diff *= 60;
X!                 diff += gmt.tm_sec - local.tm_sec;
X!                 tv.tv_sec += diff;
X! #undef    isleap
X!             } while (diff != 0 && ++iters < 5);
X!             if (iters >= 5) {
X!                 fprintf(stderr,
X!                     "date: %.24s is in the time warp!\n",
X!                     asctime(&gmt));
X!                 exit(1);
X!             }
X          }
X          tv.tv_sec = tv.tv_sec;
X          if (settimeofday(&tv, (struct timezone *)0) < 0) {
X***************
X*** 76,85
X          ap = asctime(gmtime(&tv.tv_sec));
X          tzn = "GMT";
X      } else {
X!         struct tm *tp;
X!         tp = localtime(&tv.tv_sec);
X!         ap = asctime(tp);
X!         tzn = timezone(tz.tz_minuteswest, tp->tm_isdst);
X      }
X      printf("%.20s", ap);
X      if (tzn)
X
X--- 132,139 -----
X          ap = asctime(gmtime(&tv.tv_sec));
X          tzn = "GMT";
X      } else {
X!         ap = ctime(&tv.tv_sec);
X!         tzn = tz_abbr;
X      }
X      printf("%.20s", ap);
X      if (tzn)
X***************
X*** 83,90
X      }
X      printf("%.20s", ap);
X      if (tzn)
X!         printf("%s", tzn);
X!     printf("%s", ap+19);
X      exit(rc);
X  }
X
X
X--- 137,144 -----
X      }
X      printf("%.20s", ap);
X      if (tzn)
X!         printf("%s ", tzn);
X!     printf("%s", ap+20);
X      exit(rc);
X  }
X
!The!End!

echo x - "diffs.4.3" 2>&1
sed "s/^X//" >"diffs.4.3" <<'!The!End!'
X*** date.c.4.3    Sat Jun 21 18:14:04 1986
X--- date.c.4.3.new    Sat Jun 21 18:14:04 1986
X***************
X*** 29,35
X  #define WTMP    "/usr/adm/wtmp"
X
X  struct    timeval tv, now;
X- struct    timezone tz;
X  char    *ap, *ep, *sp;
X  int    uflag, nflag;
X  int    retval;
X
X--- 29,34 -----
X  #define WTMP    "/usr/adm/wtmp"
X
X  struct    timeval tv, now;
X  char    *ap, *ep, *sp;
X  int    uflag, nflag;
X  int    retval;
X***************
X*** 34,40
X  int    uflag, nflag;
X  int    retval;
X
X- char    *timezone();
X  static    int dmsize[12] =
X      { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
X  static    char *usage = "usage: date [-n] [-u] [yymmddhhmm[.ss]]\n";
X
X--- 33,38 -----
X  int    uflag, nflag;
X  int    retval;
X
X  static    int dmsize[12] =
X      { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
X  static    char *usage = "usage: date [-n] [-u] [yymmddhhmm[.ss]]\n";
X***************
X*** 50,55
X  struct    tm *gmtime();
X  char    *strcpy(), *strncpy();
X  char    *username, *getlogin();
X  long    time();
X  uid_t    getuid();
X
X
X--- 48,54 -----
X  struct    tm *gmtime();
X  char    *strcpy(), *strncpy();
X  char    *username, *getlogin();
X+ char    *getenv();
X  long    time();
X  uid_t    getuid();
X
X***************
X*** 53,58
X  long    time();
X  uid_t    getuid();
X
X  main(argc, argv)
X      int argc;
X      char *argv[];
X
X--- 52,59 -----
X  long    time();
X  uid_t    getuid();
X
X+ extern char *tz_abbr;
X+
X  main(argc, argv)
X      int argc;
X      char *argv[];
X***************
X*** 60,66
X      register char *tzn;
X
X      openlog("date", LOG_ODELAY, LOG_AUTH);
X!     (void) gettimeofday(&tv, &tz);
X      now = tv;
X
X      while (argc > 1 && argv[1][0] == '-') {
X
X--- 61,67 -----
X      register char *tzn;
X
X      openlog("date", LOG_ODELAY, LOG_AUTH);
X!     (void) gettimeofday(&tv, (struct timezone *)0);
X      now = tv;
X
X      while (argc > 1 && argv[1][0] == '-') {
X***************
X*** 94,99
X          retval = 1;
X          goto display;
X      }
X      username = getlogin();
X      if (username == NULL || *username == '\0')  /* single-user or no tty */
X          username = "root";
X
X--- 95,104 -----
X          retval = 1;
X          goto display;
X      }
X+     if (settz(tzn = getenv("TZ")) < 0) {
X+         fprintf(stderr, "Unknown timezone \"%s\"\n", tzn ? tzn : "null");
X+         exit(1);
X+     }
X      username = getlogin();
X      if (username == NULL || *username == '\0')  /* single-user or no tty */
X          username = "root";
X***************
X*** 107,116
X      }
X      /* convert to GMT assuming local time */
X      if (uflag == 0) {
X!         tv.tv_sec += (long)tz.tz_minuteswest*60;
X!         /* now fix up local daylight time */
X!         if (localtime((time_t *)&tv.tv_sec)->tm_isdst)
X!             tv.tv_sec -= 60*60;
X      }
X      if (nflag || !settime(tv)) {
X          int wf;
X
X--- 112,171 -----
X      }
X      /* convert to GMT assuming local time */
X      if (uflag == 0) {
X!         /*
X!          * Do this by determining what the given time
X!          * is when converted to local time, and when
X!          * converted to GMT and taking the difference.
X!          * This works correctly regardless of whether
X!          * local time is DST or not.
X!          * The loop usually runs twice, once to correct the
X!          * time, and once to check the correction was accurate.
X!          * An extra iteration can be caused by setting the time
X!          * just about when DST turns on or off.
X!          * If we iterate more than a couple of times, then
X!          * the idiot root moron has asked to set the time to
X!          * something in the "dead" zone where DST has just
X!          * turned on, and the times don't exist!
X!          * The ugly "if" statements are to handle wierd cases
X!          * that arise setting the time just about midnight on
X!          * Jan 1 after a year that was a leap year.
X!          * How close to midnight it has to be depends on how close
X!          * to Greenwich you are, whether before or after midnight
X!          * depends on whether you are East or West.
X!          */
X!         struct tm gmt;
X!         struct tm local;
X!         register long diff;
X!         register int iters = 0;
X!
X!         gmt = *gmtime((time_t *)&tv.tv_sec);
X!         do {
X! #define    isleap(yr)    ((yr) % 4 == 0 && ((yr) % 100 != 0 || (yr) % 400 == 0))
X!             local = *localtime((time_t *)&tv.tv_sec);
X!             diff = gmt.tm_year - local.tm_year;
X!             diff *= 365;
X!             if (gmt.tm_year > local.tm_year) {
X!                 if (isleap(local.tm_year))
X!                     diff++;
X!             } else if (local.tm_year > gmt.tm_year) {
X!                 if (isleap(gmt.tm_year))
X!                     diff--;
X!             }
X!             diff += gmt.tm_yday - local.tm_yday;
X!             diff *= 24;
X!             diff += gmt.tm_hour - local.tm_hour;
X!             diff *= 60;
X!             diff += gmt.tm_min - local.tm_min;
X!             diff *= 60;
X!             diff += gmt.tm_sec - local.tm_sec;
X!             tv.tv_sec += diff;
X! #undef    isleap
X!         } while (diff != 0 && ++iters < 5);
X!         if (iters >= 5) {
X!             fprintf(stderr, "date: %.24s is in the time warp!\n",
X!                 asctime(&gmt));
X!             exit(1);
X!         }
X      }
X      if (nflag || !settime(tv)) {
X          int wf;
X***************
X*** 134,143
X          ap = asctime(gmtime((time_t *)&tv.tv_sec));
X          tzn = "GMT";
X      } else {
X!         struct tm *tp;
X!         tp = localtime((time_t *)&tv.tv_sec);
X!         ap = asctime(tp);
X!         tzn = timezone(tz.tz_minuteswest, tp->tm_isdst);
X      }
X      printf("%.20s", ap);
X      if (tzn)
X
X--- 189,196 -----
X          ap = asctime(gmtime((time_t *)&tv.tv_sec));
X          tzn = "GMT";
X      } else {
X!         ap = ctime((time_t *)&tv.tv_sec);
X!         tzn = tz_abbr;
X      }
X      printf("%.20s", ap);
X      if (tzn)
X***************
X*** 141,148
X      }
X      printf("%.20s", ap);
X      if (tzn)
X!         printf("%s", tzn);
X!     printf("%s", ap+19);
X      exit(retval);
X  }
X
X
X--- 194,201 -----
X      }
X      printf("%.20s", ap);
X      if (tzn)
X!         printf("%s ", tzn);
X!     printf("%s", ap+20);
X      exit(retval);
X  }
X
!The!End!

echo x - "diffs.4.3beta" 2>&1
sed "s/^X//" >"diffs.4.3beta" <<'!The!End!'
X*** date.c.4.3    Mon Apr 28 02:04:30 1986
X--- date.c.4.3.new    Mon Apr 28 02:34:09 1986
X***************
X*** 25,31
X  #define WAITDATEACK    5    /* seconds */
X
X  struct    timeval tv, now;
X- struct    timezone tz;
X  char    *ap, *ep, *sp;
X  int    uflag;
X
X
X--- 25,30 -----
X  #define WAITDATEACK    5    /* seconds */
X
X  struct    timeval tv, now;
X  char    *ap, *ep, *sp;
X  int    uflag;
X
X***************
X*** 29,35
X  char    *ap, *ep, *sp;
X  int    uflag;
X
X- char    *timezone();
X  static    int    dmsize[12] =
X      { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
X  static char *usage = "usage: date [-u] [yymmddhhmm[.ss]]\n";
X
X--- 28,33 -----
X  char    *ap, *ep, *sp;
X  int    uflag;
X
X  static    int    dmsize[12] =
X      { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
X  static char *usage = "usage: date [-u] [yymmddhhmm[.ss]]\n";
X***************
X*** 39,44
X      { "{", "", "", 0 }
X  };
X
X  char    *ctime();
X  char    *asctime();
X  struct    tm *localtime();
X
X--- 37,43 -----
X      { "{", "", "", 0 }
X  };
X
X+ char    *getenv();
X  char    *ctime();
X  char    *asctime();
X  struct    tm *localtime();
X***************
X*** 43,48
X  char    *asctime();
X  struct    tm *localtime();
X  struct    tm *gmtime();
X
X  char *strcpy();
X  char *username, *getlogin();
X
X--- 42,48 -----
X  char    *asctime();
X  struct    tm *localtime();
X  struct    tm *gmtime();
X+ extern char *tz_abbr;
X
X  char *strcpy();
X  char *username, *getlogin();
X***************
X*** 66,72
X      extern int errno;
X      int bytenetorder(), bytehostorder();
X
X!     (void) gettimeofday(&tv, &tz);
X      now = tv;
X
X      if (argc > 1 && strcmp(argv[1], "-u") == 0) {
X
X--- 66,72 -----
X      extern int errno;
X      int bytenetorder(), bytehostorder();
X
X!     (void) gettimeofday(&tv, (struct timezone *)0);
X      now = tv;
X
X      if (argc > 1 && strcmp(argv[1], "-u") == 0) {
X***************
X*** 85,90
X          printf("You are not superuser: date not set\n");
X          goto display;
X      }
X      username = getlogin();
X      if (username == NULL)        /* single-user or no tty */
X          username = "root";
X
X--- 85,94 -----
X          printf("You are not superuser: date not set\n");
X          goto display;
X      }
X+     if (settz(ap = getenv("TZ")) < 0) {
X+         fprintf(stderr, "Unknown timezone \"%s\"\n", ap ? ap : "null");
X+         exit(1);
X+     }
X      username = getlogin();
X      if (username == NULL)        /* single-user or no tty */
X          username = "root";
X***************
X*** 98,107
X      }
X      /* convert to GMT assuming local time */
X      if (uflag == 0) {
X!         tv.tv_sec += (long)tz.tz_minuteswest*60;
X!         /* now fix up local daylight time */
X!         if (localtime((time_t *)&tv.tv_sec)->tm_isdst)
X!             tv.tv_sec -= 60*60;
X      }
X
X  /*
X
X--- 102,161 -----
X      }
X      /* convert to GMT assuming local time */
X      if (uflag == 0) {
X!         /*
X!          * Do this by determining what the given time
X!          * is when converted to local time, and when
X!          * converted to GMT and taking the difference.
X!          * This works correctly regardless of whether
X!          * local time is DST or not.
X!          * The loop usually runs twice, once to correct the
X!          * time, and once to check the correction was accurate.
X!          * An extra iteration can be caused by setting the time
X!          * just about when DST turns on or off.
X!          * If we iterate more than a couple of times, then
X!          * the idiot root moron has asked to set the time to
X!          * something in the "dead" zone where DST has just
X!          * turned on, and the times don't exist!
X!          * The ugly "if" statements are to handle wierd cases
X!          * that arise setting the time just about midnight on
X!          * Jan 1 after a year that was a leap year.
X!          * How close to midnight it has to be depends on how close
X!          * to Greenwich you are, whether before or after midnight
X!          * depends on whether you are East or West.
X!          */
X!         struct tm gmt;
X!         struct tm local;
X!         register long diff;
X!         register int iters = 0;
X!
X!         gmt = *gmtime((time_t *)&tv.tv_sec);
X!         do {
X! #define    isleap(yr)    ((yr) % 4 == 0 && ((yr) % 100 != 0 || (yr) % 400 == 0))
X!             local = *localtime((time_t *)&tv.tv_sec);
X!             diff = gmt.tm_year - local.tm_year;
X!             diff *= 365;
X!             if (gmt.tm_year > local.tm_year) {
X!                 if (isleap(local.tm_year))
X!                     diff++;
X!             } else if (local.tm_year > gmt.tm_year) {
X!                 if (isleap(gmt.tm_year))
X!                     diff--;
X!             }
X!             diff += gmt.tm_yday - local.tm_yday;
X!             diff *= 24;
X!             diff += gmt.tm_hour - local.tm_hour;
X!             diff *= 60;
X!             diff += gmt.tm_min - local.tm_min;
X!             diff *= 60;
X!             diff += gmt.tm_sec - local.tm_sec;
X!             tv.tv_sec += diff;
X! #undef    isleap
X!         } while (diff != 0 && ++iters < 5);
X!         if (iters >= 5) {
X!             fprintf(stderr, "date: %.24s is in the time warp!\n",
X!                 asctime(&gmt));
X!             exit(1);
X!         }
X      }
X
X  /*
X***************
X*** 215,224
X          ap = asctime(gmtime((time_t *)&tv.tv_sec));
X          tzn = "GMT";
X      } else {
X!         struct tm *tp;
X!         tp = localtime((time_t *)&tv.tv_sec);
X!         ap = asctime(tp);
X!         tzn = timezone(tz.tz_minuteswest, tp->tm_isdst);
X      }
X      printf("%.20s", ap);
X      if (tzn)
X
X--- 269,276 -----
X          ap = asctime(gmtime((time_t *)&tv.tv_sec));
X          tzn = "GMT";
X      } else {
X!         ap = ctime((time_t *)&tv.tv_sec);
X!         tzn = tz_abbr;
X      }
X      printf("%.20s", ap);
X      if (tzn)
X***************
X*** 222,229
X      }
X      printf("%.20s", ap);
X      if (tzn)
X!         printf("%s", tzn);
X!     printf("%s", ap+19);
X  }
X
X  gtime()
X
X--- 274,281 -----
X      }
X      printf("%.20s", ap);
X      if (tzn)
X!         printf("%s ", tzn);
X!     printf("%s", ap+20);
X  }
X
X  gtime()
!The!End!

echo x - "diffs.SysV" 2>&1
sed "s/^X//" >"diffs.SysV" <<'!The!End!'
X*** date.c.SysV    Tue Apr 29 03:05:41 1986
X--- date.c.SysV.new    Tue Apr 29 03:05:42 1986
X***************
X*** 17,23
X  #define    JULIAN    itoa(tim->tm_yday+1,cp,3)
X  #define    WEEKDAY    itoa(tim->tm_wday,cp,1)
X  #define    MODHOUR    itoa(h,cp,2)
X! #define    dysize(A) (((A)%4)? 365: 366)
X
X  int dmsize[12]={31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
X
X
X--- 17,24 -----
X  #define    JULIAN    itoa(tim->tm_yday+1,cp,3)
X  #define    WEEKDAY    itoa(tim->tm_wday,cp,1)
X  #define    MODHOUR    itoa(h,cp,2)
X! #define    isleap(yr) ((yr) % 4 == 0 && ((yr) % 100 != 0 || (yr) % 400 == 0))
X! #define    dysize(A) (isleap(A)? 366: 365)
X
X  int dmsize[12]={31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
X
X***************
X*** 32,37
X      "Thu","Fri","Sat"
X  };
X
X  char    *itoa();
X  char    *cbp;
X  long    timbuf;
X
X--- 33,39 -----
X      "Thu","Fri","Sat"
X  };
X
X+ char    *getenv();
X  char    *itoa();
X  char    *cbp;
X  long    timbuf;
X***************
X*** 35,40
X  char    *itoa();
X  char    *cbp;
X  long    timbuf;
X
X  struct    utmp    wtmp[2] = { {"","",OTIME_MSG,0,OLD_TIME,0,0,0},
X                  {"","",NTIME_MSG,0,NEW_TIME,0,0,0} };
X
X--- 37,43 -----
X  char    *itoa();
X  char    *cbp;
X  long    timbuf;
X+ extern    char *tz_abbr;
X
X  struct    utmp    wtmp[2] = { {"","",OTIME_MSG,0,OLD_TIME,0,0,0},
X                  {"","",NTIME_MSG,0,NEW_TIME,0,0,0} };
X***************
X*** 48,53
X      long    tbuf, time(), lseek();
X      struct    tm  *tim;
X      char     buf[200], *tzn;
X
X      tfailed = 0;
X      if(argc > 1) {
X
X--- 51,60 -----
X      long    tbuf, time(), lseek();
X      struct    tm  *tim;
X      char     buf[200], *tzn;
X+     struct    tm gmt;
X+     struct    tm local;
X+     register long diff;
X+     register int iters = 0;
X
X      tfailed = 0;
X      if(argc > 1) {
X***************
X*** 153,158
X              exit(2);
X          }
X
X          if(gtime()) {
X              (void) fprintf(stderr,"date: bad conversion\n");
X              exit(2);
X
X--- 160,170 -----
X              exit(2);
X          }
X
X+         if (settz(cp = getenv("TZ")) < 0) {
X+             (void) fprintf(stderr,"date: unknown zone \"%s\"\n",cp);
X+             exit(2);
X+         }
X+
X          if(gtime()) {
X              (void) fprintf(stderr,"date: bad conversion\n");
X              exit(2);
X***************
X*** 159,165
X          }
X
X      /* convert to Greenwich time, on assumption of Standard time. */
X!         timbuf += timezone;
X
X      /* Now fix up to local daylight time. */
X          if (localtime(&timbuf)->tm_isdst)
X
X--- 171,225 -----
X          }
X
X      /* convert to Greenwich time, on assumption of Standard time. */
X!         /*
X!          * Do this by determining what the given time
X!          * is when converted to local time, and when
X!          * converted to GMT and taking the difference.
X!          * This works correctly regardless of whether
X!          * local time is DST or not.
X!          * The loop usually runs twice, once to correct the
X!          * time, and once to check the correction was accurate.
X!          * An extra iteration can be caused by setting the time
X!          * just about when DST turns on or off.
X!          * If we iterate more than a couple of times, then
X!          * the idiot root moron has asked to set the time to
X!          * something in the "dead" zone where DST has just
X!          * turned on, and the times don't exist!
X!          * The ugly "if" statements are to handle wierd cases
X!          * that arise setting the time just about midnight on
X!          * Jan 1 after a year that was a leap year.
X!          * How close to midnight it has to be depends on how
X!          * close to Greenwich you are, whether before or after
X!          * midnight depends on whether you are East or West.
X!          */
X!
X!         gmt = *gmtime(&tv.tv_sec);
X!         do {
X!             local = *localtime(&tv.tv_sec);
X!             diff = gmt.tm_year - local.tm_year;
X!             diff *= 365;
X!             if (gmt.tm_year > local.tm_year) {
X!                 if (isleap(local.tm_year))
X!                     diff++;
X!             } else if (local.tm_year > gmt.tm_year) {
X!                 if (isleap(gmt.tm_year))
X!                     diff--;
X!             }
X!             diff += gmt.tm_yday - local.tm_yday;
X!             diff *= 24;
X!             diff += gmt.tm_hour - local.tm_hour;
X!             diff *= 60;
X!             diff += gmt.tm_min - local.tm_min;
X!             diff *= 60;
X!             diff += gmt.tm_sec - local.tm_sec;
X!             tv.tv_sec += diff;
X!         } while (diff != 0 && ++iters < 5);
X!         if (iters >= 5) {
X!             fprintf(stderr,
X!                 "date: %.24s is in the time warp!\n",
X!                 asctime(&gmt));
X!             exit(1);
X!         }
X
X          (void) time(&wtmp[0].ut_time);
X
X***************
X*** 161,170
X      /* convert to Greenwich time, on assumption of Standard time. */
X          timbuf += timezone;
X
X-     /* Now fix up to local daylight time. */
X-         if (localtime(&timbuf)->tm_isdst)
X-             timbuf += -1*60*60;
X-
X          (void) time(&wtmp[0].ut_time);
X
X          if(stime(&timbuf) < 0) {
X
X--- 221,226 -----
X              exit(1);
X          }
X
X          (void) time(&wtmp[0].ut_time);
X
X          if(stime(&timbuf) < 0) {
X***************
X*** 188,194
X          (void) time(&timbuf);
X      cbp = ctime(&timbuf);
X      (void) write(1, cbp, 20);
X!     tzn = tzname[localtime(&timbuf)->tm_isdst];
X      if (tzn)
X          (void) write(1, tzn, 3);
X      (void) write(1, cbp+19, 6);
X
X--- 244,250 -----
X          (void) time(&timbuf);
X      cbp = ctime(&timbuf);
X      (void) write(1, cbp, 20);
X!     tzn = tz_abbr;
X      if (tzn)
X          (void) write(1, tzn, strlen(tzn));
X      (void) write(1, cbp+19, 6);
X***************
X*** 190,196
X      (void) write(1, cbp, 20);
X      tzn = tzname[localtime(&timbuf)->tm_isdst];
X      if (tzn)
X!         (void) write(1, tzn, 3);
X      (void) write(1, cbp+19, 6);
X      exit(tfailed?2:0);
X  }
X
X--- 246,252 -----
X      (void) write(1, cbp, 20);
X      tzn = tz_abbr;
X      if (tzn)
X!         (void) write(1, tzn, strlen(tzn));
X      (void) write(1, cbp+19, 6);
X      exit(tfailed?2:0);
X  }
!The!End!
exit