.

[gnulib.git] / lib / strftime.c

diff --git a/lib/strftime.c b/lib/strftime.c
index cfd41ad..e6b0c5a 100644 (file)
--- a/lib/strftime.c
+++ b/lib/strftime.c
@@ -46,9 +46,11 @@
    %p  locale's AM or PM
    %r  time, 12-hour (hh:mm:ss [AP]M)
    %R  time, 24-hour (hh:mm)
+   %s  time in seconds since 00:00:00, Jan 1, 1970 (a nonstandard extension)
    %S  second (00..61)
    %T  time, 24-hour (hh:mm:ss)
    %X  locale's time representation (%H:%M:%S)
+   %z   RFC-822 style numeric timezone (-0500) (a nonstandard extension)
    %Z  time zone (EDT), or nothing if no time zone is determinable
 
    Date fields:
@@ -73,6 +75,11 @@
 
    David MacKenzie <djm@gnu.ai.mit.edu> */
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
 #include <sys/types.h>
 #if defined(TM_IN_SYS_TIME) || (!defined(HAVE_TM_ZONE) && !defined(HAVE_TZNAME))
 #include <sys/time.h>
@@ -80,6 +87,10 @@
 #include <time.h>
 #endif
 
+#ifndef STDC_HEADERS
+time_t mktime ();
+#endif
+
 #if defined(HAVE_TZNAME)
 extern char *tzname[2];
 #endif
@@ -164,7 +175,7 @@ add_num3 (string, num, max, pad)
 static int
 add_str (to, from, max)
      char *to;
-     char *from;
+     const char *from;
      int max;
 {
   int i;
@@ -174,6 +185,54 @@ add_str (to, from, max)
   return i;
 }
 
+static int
+add_num_time_t (string, max, num)
+     char *string;
+     int max;
+     time_t num;
+{
+  /* This buffer is large enough to hold the character representation
+     (including the trailing NUL) of any unsigned decimal quantity
+     whose binary representation fits in 128 bits.  */
+  char buf[40];
+  int length;
+
+  if (sizeof (num) > 16)
+    abort ();
+  sprintf (buf, "%lu", (unsigned long) num);
+  length = add_str (string, buf, max);
+  return length;
+}
+
+/* Convert MINUTES_EAST into a string suitable for use as the RFC-822
+   timezone indicator.  Write no more than MAX bytes into STRING.
+    Return the number of bytes written into STRING.  */
+
+static int
+add_num_tz (string, max, minutes_east)
+     char *string;
+     int max;
+     int minutes_east;
+{
+  int length;
+
+  if (max < 1)
+    return 0;
+
+  if (minutes_east < 0)
+    {
+      *string = '-';
+      minutes_east = -minutes_east;
+    }
+  else
+    *string = '+';
+
+  length = 1 + add_num2 (&string[1], (minutes_east / 60) % 24, max - 1, zero);
+  length += add_num2 (&string[length], minutes_east % 60, max - length, zero);
+
+  return length;
+}
+
 /* Return the week in the year of the time in TM, with the weeks
    starting on Sundays. */
 
@@ -319,6 +378,16 @@ strftime (string, max, format, tm)
              length +=
                strftime (&string[length], max - length, "%H:%M", tm);
              break;
+
+           case 's':
+             {
+               struct tm writable_tm;
+               writable_tm = *tm;
+               length += add_num_time_t (&string[length], max - length,
+                                         mktime (&writable_tm));
+             }
+             break;
+
            case 'S':
              length +=
                add_num2 (&string[length], tm->tm_sec, max - length, pad);
@@ -331,6 +400,37 @@ strftime (string, max, format, tm)
              length +=
                strftime (&string[length], max - length, "%H:%M:%S", tm);
              break;
+           case 'z':
+             {
+               time_t t;
+               struct tm tml, tmg;
+               int diff;
+
+               tml = *tm;
+               t = mktime (&tml);
+               tml = *localtime (&t); /* Canonicalize the local time */
+               tmg = *gmtime (&t);
+
+               /* Compute the difference */
+
+               diff = tml.tm_min - tmg.tm_min;
+               diff += 60 * (tml.tm_hour - tmg.tm_hour);
+
+               if (tml.tm_mon != tmg.tm_mon)
+                 {
+                   /* We assume no timezone differs from UTC by more than
+                      +- 23 hours.  This should be safe. */
+                   if (tmg.tm_mday == 1)
+                     tml.tm_mday = 0;
+                   else /* tml.tm_mday == 1 */
+                     tmg.tm_mday = 0;
+                 }
+
+               diff += 1440 * (tml.tm_mday - tmg.tm_mday);
+
+               length += add_num_tz (&string[length], max - length, diff);
+             }
+             break;
            case 'Z':
 #ifdef HAVE_TM_ZONE
              length += add_str (&string[length], tm->tm_zone, max - length);