}
\f
+static int
+lisp_time_argument (specified_time, result)
+ Lisp_Object specified_time;
+ time_t *result;
+{
+ if (NILP (specified_time))
+ return time (result) != -1;
+ else
+ {
+ Lisp_Object high, low;
+ high = Fcar (specified_time);
+ CHECK_NUMBER (high, 0);
+ low = Fcdr (specified_time);
+ if (XTYPE (low) == Lisp_Cons)
+ low = Fcar (low);
+ CHECK_NUMBER (low, 0);
+ *result = (XINT (high) << 16) + (XINT (low) & 0xffff);
+ return *result >> 16 == XINT (high);
+ }
+}
+
DEFUN ("current-time-string", Fcurrent_time_string, Scurrent_time_string, 0, 1, 0,
"Return the current time, as a human-readable string.\n\
Programs can use this function to decode a time,\n\
(specified_time)
Lisp_Object specified_time;
{
- long value;
+ time_t value;
char buf[30];
register char *tem;
- if (NILP (specified_time))
- value = time ((long *) 0);
- else
- {
- Lisp_Object high, low;
- high = Fcar (specified_time);
- CHECK_NUMBER (high, 0);
- low = Fcdr (specified_time);
- if (XTYPE (low) == Lisp_Cons)
- low = Fcar (low);
- CHECK_NUMBER (low, 0);
- value = ((XINT (high) << 16) + (XINT (low) & 0xffff));
- }
-
+ if (! lisp_time_argument (specified_time, &value))
+ value = -1;
tem = (char *) ctime (&value);
strncpy (buf, tem, 24);
return build_string (buf);
}
-DEFUN ("current-time-zone", Fcurrent_time_zone, Scurrent_time_zone, 0, 0, 0,
- "Return the offset, savings state, and names for the current time zone.\n\
-This returns a list of the form (OFFSET SAVINGS-FLAG STANDARD SAVINGS).\n\
-OFFSET is an integer specifying how many minutes east of Greenwich the\n\
- current time zone is located. A negative value means west of\n\
- Greenwich. Note that this describes the standard time; if daylight\n\
- savings time is in effect, it does not affect this value.\n\
-SAVINGS-FLAG is non-nil iff daylight savings time or some other sort\n\
- of seasonal time adjustment is in effect.\n\
-STANDARD is a string giving the name of the time zone when no seasonal\n\
- time adjustment is in effect.\n\
-SAVINGS is a string giving the name of the time zone when there is a\n\
- seasonal time adjustment in effect.\n\
-If the local area does not use a seasonal time adjustment,\n\
-SAVINGS-FLAG is always nil, and STANDARD and SAVINGS are equal.\n\
+#define TM_YEAR_ORIGIN 1900
+
+/* Yield A - B, measured in seconds. */
+static long
+difftm(a, b)
+ struct tm *a, *b;
+{
+ int ay = a->tm_year + (TM_YEAR_ORIGIN - 1);
+ int by = b->tm_year + (TM_YEAR_ORIGIN - 1);
+ return
+ (
+ (
+ (
+ /* difference in day of year */
+ a->tm_yday - b->tm_yday
+ /* + intervening leap days */
+ + ((ay >> 2) - (by >> 2))
+ - (ay/100 - by/100)
+ + ((ay/100 >> 2) - (by/100 >> 2))
+ /* + difference in years * 365 */
+ + (long)(ay-by) * 365
+ )*24 + (a->tm_hour - b->tm_hour)
+ )*60 + (a->tm_min - b->tm_min)
+ )*60 + (a->tm_sec - b->tm_sec);
+}
+
+DEFUN ("current-time-zone", Fcurrent_time_zone, Scurrent_time_zone, 0, 1, 0,
+ "Return the offset and name for the local time zone.\n\
+This returns a list of the form (OFFSET NAME).\n\
+OFFSET is an integer number of seconds ahead of UTC (east of Greenwich).\n\
+ A negative value means west of Greenwich.\n\
+NAME is a string giving the name of the time zone.\n\
+If an argument is given, it specifies when the time zone offset is determined\n\
+instead of using the current time. The argument should have the form:\n\
+ (HIGH . LOW)\n\
+or the form:\n\
+ (HIGH LOW . IGNORED).\n\
+Thus, you can use times obtained from `current-time'\n\
+and from `file-attributes'.\n\
\n\
Some operating systems cannot provide all this information to Emacs;\n\
in this case, current-time-zone will return a list containing nil for\n\
the data it can't find.")
- ()
+ (specified_time)
+ Lisp_Object specified_time;
{
-#ifdef EMACS_CURRENT_TIME_ZONE
- int offset, savings_flag;
- char standard[11];
- char savings[11];
-
- EMACS_CURRENT_TIME_ZONE (&offset, &savings_flag, standard, savings);
-
- return Fcons (make_number (offset),
- Fcons ((savings_flag ? Qt : Qnil),
- Fcons (build_string (standard),
- Fcons (build_string (savings),
- Qnil))));
-#else
- return Fmake_list (4, Qnil);
+ time_t value;
+ struct tm *t;
+
+ if (lisp_time_argument (specified_time, &value)
+ && (t = gmtime(&value)) != 0)
+ {
+ struct tm gmt = *t; /* Make a copy, in case localtime modifies *t. */
+ long offset;
+ char *s, buf[6];
+ t = localtime(&value);
+ offset = difftm(t, &gmt);
+ s = 0;
+#ifdef HAVE_TM_ZONE
+ if (t->tm_zone)
+ s = t->tm_zone;
#endif
+ if (!s)
+ {
+ /* No local time zone name is available; use "+-NNNN" instead. */
+ long am = (offset < 0 ? -offset : offset) / 60;
+ sprintf (buf, "%c%02d%02d", (offset < 0 ? '-' : '+'), am/60, am%60);
+ s = buf;
+ }
+ return Fcons (make_number (offset), Fcons (build_string (s), Qnil));
+ }
+ else
+ return Fmake_list (2, Qnil);
}
\f
HCoop / bpt / emacs.git / blobdiff