git-filter-branch: more detailed USAGE

diff --git a/date.c b/date.c
index 0ceccbe03401faa67836577b9bdbe139fe025dd5..93bef6efbe38cb8983fdda14b75ce772f90e1b6a 100644 (file)
--- a/date.c
+++ b/date.c
@@ -55,6 +55,32 @@ static struct tm *time_to_tm(unsigned long time, int tz)
        return gmtime(&t);
 }
 
+/*
+ * What value of "tz" was in effect back then at "time" in the
+ * local timezone?
+ */
+static int local_tzoffset(unsigned long time)
+{
+       time_t t, t_local;
+       struct tm tm;
+       int offset, eastwest;
+
+       t = time;
+       localtime_r(&t, &tm);
+       t_local = my_mktime(&tm);
+
+       if (t_local < t) {
+               eastwest = -1;
+               offset = t - t_local;
+       } else {
+               eastwest = 1;
+               offset = t_local - t;
+       }
+       offset /= 60; /* in minutes */
+       offset = (offset % 60) + ((offset / 60) * 100);
+       return offset * eastwest;
+}
+
 const char *show_date(unsigned long time, int tz, enum date_mode mode)
 {
        struct tm *tm;
@@ -102,34 +128,36 @@ const char *show_date(unsigned long time, int tz, enum date_mode mode)
                /* Else fall back on absolute format.. */
        }
 
+       if (mode == DATE_LOCAL)
+               tz = local_tzoffset(time);
+
        tm = time_to_tm(time, tz);
        if (!tm)
                return NULL;
        if (mode == DATE_SHORT)
                sprintf(timebuf, "%04d-%02d-%02d", tm->tm_year + 1900,
                                tm->tm_mon + 1, tm->tm_mday);
+       else if (mode == DATE_ISO8601)
+               sprintf(timebuf, "%04d-%02d-%02d %02d:%02d:%02d %+05d",
+                               tm->tm_year + 1900,
+                               tm->tm_mon + 1,
+                               tm->tm_mday,
+                               tm->tm_hour, tm->tm_min, tm->tm_sec,
+                               tz);
+       else if (mode == DATE_RFC2822)
+               sprintf(timebuf, "%.3s, %d %.3s %d %02d:%02d:%02d %+05d",
+                       weekday_names[tm->tm_wday], tm->tm_mday,
+                       month_names[tm->tm_mon], tm->tm_year + 1900,
+                       tm->tm_hour, tm->tm_min, tm->tm_sec, tz);
        else
-               sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d %+05d",
+               sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d%c%+05d",
                                weekday_names[tm->tm_wday],
                                month_names[tm->tm_mon],
                                tm->tm_mday,
                                tm->tm_hour, tm->tm_min, tm->tm_sec,
-                               tm->tm_year + 1900, tz);
-       return timebuf;
-}
-
-const char *show_rfc2822_date(unsigned long time, int tz)
-{
-       struct tm *tm;
-       static char timebuf[200];
-
-       tm = time_to_tm(time, tz);
-       if (!tm)
-               return NULL;
-       sprintf(timebuf, "%.3s, %d %.3s %d %02d:%02d:%02d %+05d",
-               weekday_names[tm->tm_wday], tm->tm_mday,
-               month_names[tm->tm_mon], tm->tm_year + 1900,
-               tm->tm_hour, tm->tm_min, tm->tm_sec, tz);
+                               tm->tm_year + 1900,
+                               (mode == DATE_LOCAL) ? 0 : ' ',
+                               tz);
        return timebuf;
 }
 
@@ -372,7 +400,7 @@ static int match_multi_number(unsigned long num, char c, const char *date, char
 }
 
 /*
- * We've seen a digit. Time? Year? Date? 
+ * We've seen a digit. Time? Year? Date?
  */
 static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt)
 {
@@ -383,9 +411,11 @@ static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt
        num = strtoul(date, &end, 10);
 
        /*
-        * Seconds since 1970? We trigger on that for anything after Jan 1, 2000
+        * Seconds since 1970? We trigger on that for any numbers with
+        * more than 8 digits. This is because we don't want to rule out
+        * numbers like 20070606 as a YYYYMMDD date.
         */
-       if (num > 946684800) {
+       if (num >= 100000000) {
                time_t time = num;
                if (gmtime_r(&time, tm)) {
                        *tm_gmt = 1;
@@ -462,7 +492,7 @@ static int match_digit(const char *date, struct tm *tm, int *offset, int *tm_gmt
        } else if (num > 0 && num < 13) {
                tm->tm_mon = num-1;
        }
-               
+
        return n;
 }
 
@@ -536,13 +566,13 @@ int parse_date(const char *date, char *result, int maxlen)
                if (!match) {
                        /* BAD CRAP */
                        match = 1;
-               }       
+               }
 
                date += match;
        }
 
        /* mktime uses local timezone */
-       then = my_mktime(&tm); 
+       then = my_mktime(&tm);
        if (offset == -1)
                offset = (then - mktime(&tm)) / 60;
 
@@ -630,6 +660,14 @@ static void date_am(struct tm *tm, int *num)
        tm->tm_hour = (hour % 12);
 }
 
+static void date_never(struct tm *tm, int *num)
+{
+       tm->tm_mon = tm->tm_wday = tm->tm_yday
+               = tm->tm_hour = tm->tm_min = tm->tm_sec = 0;
+       tm->tm_year = 70;
+       tm->tm_mday = 1;
+}
+
 static const struct special {
        const char *name;
        void (*fn)(struct tm *, int *);
@@ -640,6 +678,7 @@ static const struct special {
        { "tea", date_tea },
        { "PM", date_pm },
        { "AM", date_am },
+       { "never", date_never },
        { NULL }
 };
 
@@ -658,7 +697,7 @@ static const struct typelen {
        { "days", 24*60*60 },
        { "weeks", 7*24*60*60 },
        { NULL }
-};     
+};
 
 static const char *approxidate_alpha(const char *date, struct tm *tm, int *num)
 {