source: trunk/libs/newlib/src/newlib/libc/time/tzset_r.c @ 543

#include <_ansi.h>
#include <reent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/time.h>
#include "local.h"

#define sscanf siscanf  /* avoid to pull in FP functions. */

static char __tzname_std[11];
static char __tzname_dst[11];
static char *prev_tzenv = NULL;

void
_tzset_unlocked_r (struct _reent *reent_ptr)
{
  char *tzenv;
  unsigned short hh, mm, ss, m, w, d;
  int sign, n;
  int i, ch;
  __tzinfo_type *tz = __gettzinfo ();

  if ((tzenv = _getenv_r (reent_ptr, "TZ")) == NULL)
      {
        _timezone = 0;
        _daylight = 0;
        _tzname[0] = "GMT";
        _tzname[1] = "GMT";
        free(prev_tzenv);
        prev_tzenv = NULL;
        return;
      }

  if (prev_tzenv != NULL && strcmp(tzenv, prev_tzenv) == 0)
    return;

  free(prev_tzenv);
  prev_tzenv = _malloc_r (reent_ptr, strlen(tzenv) + 1);
  if (prev_tzenv != NULL)
    strcpy (prev_tzenv, tzenv);

  /* ignore implementation-specific format specifier */
  if (*tzenv == ':')
    ++tzenv;  

  if (sscanf (tzenv, "%10[^0-9,+-]%n", __tzname_std, &n) <= 0)
    return;
 
  tzenv += n;

  sign = 1;
  if (*tzenv == '-')
    {
      sign = -1;
      ++tzenv;
    }
  else if (*tzenv == '+')
    ++tzenv;

  mm = 0;
  ss = 0;
 
  if (sscanf (tzenv, "%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n) < 1)
    return;
  
  tz->__tzrule[0].offset = sign * (ss + SECSPERMIN * mm + SECSPERHOUR * hh);
  _tzname[0] = __tzname_std;
  tzenv += n;
  
  if (sscanf (tzenv, "%10[^0-9,+-]%n", __tzname_dst, &n) <= 0)
    { /* No dst */
      _tzname[1] = _tzname[0];
      _timezone = tz->__tzrule[0].offset;
      _daylight = 0;
      return;
    }
  else
    _tzname[1] = __tzname_dst;

  tzenv += n;

  /* otherwise we have a dst name, look for the offset */
  sign = 1;
  if (*tzenv == '-')
    {
      sign = -1;
      ++tzenv;
    }
  else if (*tzenv == '+')
    ++tzenv;

  hh = 0;  
  mm = 0;
  ss = 0;
  
  n  = 0;
  if (sscanf (tzenv, "%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n) <= 0)
    tz->__tzrule[1].offset = tz->__tzrule[0].offset - 3600;
  else
    tz->__tzrule[1].offset = sign * (ss + SECSPERMIN * mm + SECSPERHOUR * hh);

  tzenv += n;

  for (i = 0; i < 2; ++i)
    {
      if (*tzenv == ',')
        ++tzenv;

      if (*tzenv == 'M')
        {
          if (sscanf (tzenv, "M%hu%n.%hu%n.%hu%n", &m, &n, &w, &n, &d, &n) != 3 ||
              m < 1 || m > 12 || w < 1 || w > 5 || d > 6)
            return;
          
          tz->__tzrule[i].ch = 'M';
          tz->__tzrule[i].m = m;
          tz->__tzrule[i].n = w;
          tz->__tzrule[i].d = d;
          
          tzenv += n;
        }
      else 
        {
          char *end;
          if (*tzenv == 'J')
            {
              ch = 'J';
              ++tzenv;
            }
          else
            ch = 'D';
          
          d = strtoul (tzenv, &end, 10);
          
          /* if unspecified, default to US settings */
          /* From 1987-2006, US was M4.1.0,M10.5.0, but starting in 2007 is
           * M3.2.0,M11.1.0 (2nd Sunday March through 1st Sunday November)  */
          if (end == tzenv)
            {
              if (i == 0)
                {
                  tz->__tzrule[0].ch = 'M';
                  tz->__tzrule[0].m = 3;
                  tz->__tzrule[0].n = 2;
                  tz->__tzrule[0].d = 0;
                }
              else
                {
                  tz->__tzrule[1].ch = 'M';
                  tz->__tzrule[1].m = 11;
                  tz->__tzrule[1].n = 1;
                  tz->__tzrule[1].d = 0;
                }
            }
          else
            {
              tz->__tzrule[i].ch = ch;
              tz->__tzrule[i].d = d;
            }
          
          tzenv = end;
        }
      
      /* default time is 02:00:00 am */
      hh = 2;
      mm = 0;
      ss = 0;
      n = 0;
      
      if (*tzenv == '/')
        sscanf (tzenv, "/%hu%n:%hu%n:%hu%n", &hh, &n, &mm, &n, &ss, &n);

      tz->__tzrule[i].s = ss + SECSPERMIN * mm + SECSPERHOUR  * hh;
      
      tzenv += n;
    }

  __tzcalc_limits (tz->__tzyear);
  _timezone = tz->__tzrule[0].offset;  
  _daylight = tz->__tzrule[0].offset != tz->__tzrule[1].offset;
}

void
_tzset_r (struct _reent *reent_ptr)
{
  TZ_LOCK;
  _tzset_unlocked_r (reent_ptr);
  TZ_UNLOCK;
}