Add strptime into the source pool for those systems that don't have it.

Originally committed as revision 818 to svn://svn.ffmpeg.org/ffmpeg/trunk

libav/strptime.c

+/* Convert a string representation of time to a time value.
+   Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Library General Public License as
+   published by the Free Software Foundation; either version 2 of the
+   License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Library General Public License for more details.
+
+   You should have received a copy of the GNU Library General Public
+   License along with the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+/* XXX This version of the implementation is not really complete.
+   Some of the fields cannot add information alone.  But if seeing
+   some of them in the same format (such as year, week and weekday)
+   this is enough information for determining the date.  */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <ctype.h>
+#include <limits.h>
+#include <string.h>
+#include <time.h>
+
+#ifdef _LIBC
+# include "../locale/localeinfo.h"
+#endif
+
+#include "strptime.h"
+
+#ifndef __P
+# if defined (__GNUC__) || (defined (__STDC__) && __STDC__)
+#  define __P(args) args
+# else
+#  define __P(args) ()
+# endif  /* GCC.  */
+#endif  /* Not __P.  */
+
+#if ! HAVE_LOCALTIME_R && ! defined localtime_r
+# ifdef _LIBC
+#  define localtime_r __localtime_r
+# else
+/* Approximate localtime_r as best we can in its absence.  */
+#  define localtime_r my_localtime_r
+static struct tm *localtime_r __P ((const time_t *, struct tm *));
+static struct tm *
+localtime_r (t, tp)
+     const time_t *t;
+     struct tm *tp;
+{
+  struct tm *l = localtime (t);
+  if (! l)
+    return 0;
+  *tp = *l;
+  return tp;
+}
+# endif /* ! _LIBC */
+#endif /* ! HAVE_LOCALTIME_R && ! defined (localtime_r) */
+
+
+#define match_char(ch1, ch2) if (ch1 != ch2) return NULL
+#if defined __GNUC__ && __GNUC__ >= 2
+# define match_string(cs1, s2) \
+  ({ size_t len = strlen (cs1);						      \
+     int result = strncasecmp ((cs1), (s2), len) == 0;			      \
+     if (result) (s2) += len;						      \
+     result; })
+#else
+/* Oh come on.  Get a reasonable compiler.  */
+# define match_string(cs1, s2) \
+  (strncasecmp ((cs1), (s2), strlen (cs1)) ? 0 : ((s2) += strlen (cs1), 1))
+#endif
+/* We intentionally do not use isdigit() for testing because this will
+   lead to problems with the wide character version.  */
+#define get_number(from, to, n) \
+  do {									      \
+    int __n = n;							      \
+    val = 0;								      \
+    while (*rp == ' ')							      \
+      ++rp;								      \
+    if (*rp < '0' || *rp > '9')						      \
+      return NULL;							      \
+    do {								      \
+      val *= 10;							      \
+      val += *rp++ - '0';						      \
+    } while (--__n > 0 && val * 10 <= to && *rp >= '0' && *rp <= '9');	      \
+    if (val < from || val > to)						      \
+      return NULL;							      \
+  } while (0)
+#ifdef _NL_CURRENT
+# define get_alt_number(from, to, n) \
+  ({									      \
+    __label__ do_normal;						      \
+    if (*decided != raw)						      \
+      {									      \
+	const char *alts = _NL_CURRENT (LC_TIME, ALT_DIGITS);		      \
+	int __n = n;							      \
+	int any = 0;							      \
+	while (*rp == ' ')						      \
+	  ++rp;								      \
+	val = 0;							      \
+	do {								      \
+	  val *= 10;							      \
+	  while (*alts != '\0')						      \
+	    {								      \
+	      size_t len = strlen (alts);				      \
+	      if (strncasecmp (alts, rp, len) == 0)			      \
+	        break;							      \
+	      alts += len + 1;						      \
+	      ++val;							      \
+	    }								      \
+	  if (*alts == '\0')						      \
+	    {								      \
+	      if (*decided == not && ! any)				      \
+		goto do_normal;						      \
+	      /* If we haven't read anything it's an error.  */		      \
+	      if (! any)						      \
+		return NULL;						      \
+	      /* Correct the premature multiplication.  */		      \
+	      val /= 10;						      \
+	      break;							      \
+	    }								      \
+	  else								      \
+	    *decided = loc;						      \
+	} while (--__n > 0 && val * 10 <= to);				      \
+	if (val < from || val > to)					      \
+	  return NULL;							      \
+      }									      \
+    else								      \
+      {									      \
+       do_normal:							      \
+        get_number (from, to, n);					      \
+      }									      \
+    0;									      \
+  })
+#else
+# define get_alt_number(from, to, n) \
+  /* We don't have the alternate representation.  */			      \
+  get_number(from, to, n)
+#endif
+#define recursive(new_fmt) \
+  (*(new_fmt) != '\0'							      \
+   && (rp = strptime_internal (rp, (new_fmt), tm, decided, era_cnt)) != NULL)
+
+
+#ifdef _LIBC
+/* This is defined in locale/C-time.c in the GNU libc.  */
+extern const struct locale_data _nl_C_LC_TIME;
+extern const unsigned short int __mon_yday[2][13];
+
+# define weekday_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (DAY_1)].string)
+# define ab_weekday_name \
+  (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (ABDAY_1)].string)
+# define month_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (MON_1)].string)
+# define ab_month_name (&_nl_C_LC_TIME.values[_NL_ITEM_INDEX (ABMON_1)].string)
+# define HERE_D_T_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (D_T_FMT)].string)
+# define HERE_D_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (D_FMT)].string)
+# define HERE_AM_STR (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (AM_STR)].string)
+# define HERE_PM_STR (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (PM_STR)].string)
+# define HERE_T_FMT_AMPM \
+  (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (T_FMT_AMPM)].string)
+# define HERE_T_FMT (_nl_C_LC_TIME.values[_NL_ITEM_INDEX (T_FMT)].string)
+
+# define strncasecmp(s1, s2, n) __strncasecmp (s1, s2, n)
+#else
+static char const weekday_name[][10] =
+  {
+    "Sunday", "Monday", "Tuesday", "Wednesday",
+    "Thursday", "Friday", "Saturday"
+  };
+static char const ab_weekday_name[][4] =
+  {
+    "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
+  };
+static char const month_name[][10] =
+  {
+    "January", "February", "March", "April", "May", "June",
+    "July", "August", "September", "October", "November", "December"
+  };
+static char const ab_month_name[][4] =
+  {
+    "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+  };
+# define HERE_D_T_FMT "%a %b %e %H:%M:%S %Y"
+# define HERE_D_FMT "%m/%d/%y"
+# define HERE_AM_STR "AM"
+# define HERE_PM_STR "PM"
+# define HERE_T_FMT_AMPM "%I:%M:%S %p"
+# define HERE_T_FMT "%H:%M:%S"
+
+const unsigned short int __mon_yday[2][13] =
+  {
+    /* Normal years.  */
+    { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
+    /* Leap years.  */
+    { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
+  };
+#endif
+
+/* Status of lookup: do we use the locale data or the raw data?  */
+enum locale_status { not, loc, raw };
+
+
+#ifndef __isleap
+/* Nonzero if YEAR is a leap year (every 4 years,
+   except every 100th isn't, and every 400th is).  */
+# define __isleap(year)	\
+  ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
+#endif
+
+/* Compute the day of the week.  */
+static void
+day_of_the_week (struct tm *tm)
+{
+  /* We know that January 1st 1970 was a Thursday (= 4).  Compute the
+     the difference between this data in the one on TM and so determine
+     the weekday.  */
+  int corr_year = 1900 + tm->tm_year - (tm->tm_mon < 2);
+  int wday = (-473
+	      + (365 * (tm->tm_year - 70))
+	      + (corr_year / 4)
+	      - ((corr_year / 4) / 25) + ((corr_year / 4) % 25 < 0)
+	      + (((corr_year / 4) / 25) / 4)
+	      + __mon_yday[0][tm->tm_mon]
+	      + tm->tm_mday - 1);
+  tm->tm_wday = ((wday % 7) + 7) % 7;
+}
+
+/* Compute the day of the year.  */
+static void
+day_of_the_year (struct tm *tm)
+{
+  tm->tm_yday = (__mon_yday[__isleap (1900 + tm->tm_year)][tm->tm_mon]
+		 + (tm->tm_mday - 1));
+}
+
+static char *
+#ifdef _LIBC
+internal_function
+#endif
+strptime_internal __P ((const char *rp, const char *fmt, struct tm *tm,
+			enum locale_status *decided, int era_cnt));
+
+static char *
+#ifdef _LIBC
+internal_function
+#endif
+strptime_internal (rp, fmt, tm, decided, era_cnt)
+     const char *rp;
+     const char *fmt;
+     struct tm *tm;
+     enum locale_status *decided;
+     int era_cnt;
+{
+  const char *rp_backup;
+  int cnt;
+  size_t val;
+  int have_I, is_pm;
+  int century, want_century;
+  int want_era;
+  int have_wday, want_xday;
+  int have_yday;
+  int have_mon, have_mday;
+#ifdef _NL_CURRENT
+  size_t num_eras;
+#endif
+  struct era_entry *era;
+
+  have_I = is_pm = 0;
+  century = -1;
+  want_century = 0;
+  want_era = 0;
+  era = NULL;
+
+  have_wday = want_xday = have_yday = have_mon = have_mday = 0;
+
+  while (*fmt != '\0')
+    {
+      /* A white space in the format string matches 0 more or white
+	 space in the input string.  */
+      if (isspace (*fmt))
+	{
+	  while (isspace (*rp))
+	    ++rp;
+	  ++fmt;
+	  continue;
+	}
+
+      /* Any character but `%' must be matched by the same character
+	 in the iput string.  */
+      if (*fmt != '%')
+	{
+	  match_char (*fmt++, *rp++);
+	  continue;
+	}
+
+      ++fmt;
+#ifndef _NL_CURRENT
+      /* We need this for handling the `E' modifier.  */
+    start_over:
+#endif
+
+      /* Make back up of current processing pointer.  */
+      rp_backup = rp;
+
+      switch (*fmt++)
+	{
+	case '%':
+	  /* Match the `%' character itself.  */
+	  match_char ('%', *rp++);
+	  break;
+	case 'a':
+	case 'A':
+	  /* Match day of week.  */
+	  for (cnt = 0; cnt < 7; ++cnt)
+	    {
+#ifdef _NL_CURRENT
+	      if (*decided !=raw)
+		{
+		  if (match_string (_NL_CURRENT (LC_TIME, DAY_1 + cnt), rp))
+		    {
+		      if (*decided == not
+			  && strcmp (_NL_CURRENT (LC_TIME, DAY_1 + cnt),
+				     weekday_name[cnt]))
+			*decided = loc;
+		      break;
+		    }
+		  if (match_string (_NL_CURRENT (LC_TIME, ABDAY_1 + cnt), rp))
+		    {
+		      if (*decided == not
+			  && strcmp (_NL_CURRENT (LC_TIME, ABDAY_1 + cnt),
+				     ab_weekday_name[cnt]))
+			*decided = loc;
+		      break;
+		    }
+		}
+#endif
+	      if (*decided != loc
+		  && (match_string (weekday_name[cnt], rp)
+		      || match_string (ab_weekday_name[cnt], rp)))
+		{
+		  *decided = raw;
+		  break;
+		}
+	    }
+	  if (cnt == 7)
+	    /* Does not match a weekday name.  */
+	    return NULL;
+	  tm->tm_wday = cnt;
+	  have_wday = 1;
+	  break;
+	case 'b':
+	case 'B':
+	case 'h':
+	  /* Match month name.  */
+	  for (cnt = 0; cnt < 12; ++cnt)
+	    {
+#ifdef _NL_CURRENT
+	      if (*decided !=raw)
+		{
+		  if (match_string (_NL_CURRENT (LC_TIME, MON_1 + cnt), rp))
+		    {
+		      if (*decided == not
+			  && strcmp (_NL_CURRENT (LC_TIME, MON_1 + cnt),
+				     month_name[cnt]))
+			*decided = loc;
+		      break;
+		    }
+		  if (match_string (_NL_CURRENT (LC_TIME, ABMON_1 + cnt), rp))
+		    {
+		      if (*decided == not
+			  && strcmp (_NL_CURRENT (LC_TIME, ABMON_1 + cnt),
+				     ab_month_name[cnt]))
+			*decided = loc;
+		      break;
+		    }
+		}
+#endif
+	      if (match_string (month_name[cnt], rp)
+		  || match_string (ab_month_name[cnt], rp))
+		{
+		  *decided = raw;
+		  break;
+		}
+	    }
+	  if (cnt == 12)
+	    /* Does not match a month name.  */
+	    return NULL;
+	  tm->tm_mon = cnt;
+	  want_xday = 1;
+	  break;
+	case 'c':
+	  /* Match locale's date and time format.  */
+#ifdef _NL_CURRENT
+	  if (*decided != raw)
+	    {
+	      if (!recursive (_NL_CURRENT (LC_TIME, D_T_FMT)))
+		{
+		  if (*decided == loc)
+		    return NULL;
+		  else
+		    rp = rp_backup;
+		}
+	      else
+		{
+		  if (*decided == not &&
+		      strcmp (_NL_CURRENT (LC_TIME, D_T_FMT), HERE_D_T_FMT))
+		    *decided = loc;
+		  want_xday = 1;
+		  break;
+		}
+	      *decided = raw;
+	    }
+#endif
+	  if (!recursive (HERE_D_T_FMT))
+	    return NULL;
+	  want_xday = 1;
+	  break;
+	case 'C':
+	  /* Match century number.  */
+#ifdef _NL_CURRENT
+	match_century:
+#endif
+	  get_number (0, 99, 2);
+	  century = val;
+	  want_xday = 1;
+	  break;
+	case 'd':
+	case 'e':
+	  /* Match day of month.  */
+	  get_number (1, 31, 2);
+	  tm->tm_mday = val;
+	  have_mday = 1;
+	  want_xday = 1;
+	  break;
+	case 'F':
+	  if (!recursive ("%Y-%m-%d"))
+	    return NULL;
+	  want_xday = 1;
+	  break;
+	case 'x':
+#ifdef _NL_CURRENT
+	  if (*decided != raw)
+	    {
+	      if (!recursive (_NL_CURRENT (LC_TIME, D_FMT)))
+		{
+		  if (*decided == loc)
+		    return NULL;
+		  else
+		    rp = rp_backup;
+		}
+	      else
+		{
+		  if (*decided == not
+		      && strcmp (_NL_CURRENT (LC_TIME, D_FMT), HERE_D_FMT))
+		    *decided = loc;
+		  want_xday = 1;
+		  break;
+		}
+	      *decided = raw;
+	    }
+#endif
+	  /* Fall through.  */
+	case 'D':
+	  /* Match standard day format.  */
+	  if (!recursive (HERE_D_FMT))
+	    return NULL;
+	  want_xday = 1;
+	  break;
+	case 'k':
+	case 'H':
+	  /* Match hour in 24-hour clock.  */
+	  get_number (0, 23, 2);
+	  tm->tm_hour = val;
+	  have_I = 0;
+	  break;
+	case 'I':
+	  /* Match hour in 12-hour clock.  */
+	  get_number (1, 12, 2);
+	  tm->tm_hour = val % 12;
+	  have_I = 1;
+	  break;
+	case 'j':
+	  /* Match day number of year.  */
+	  get_number (1, 366, 3);
+	  tm->tm_yday = val - 1;
+	  have_yday = 1;
+	  break;
+	case 'm':
+	  /* Match number of month.  */
+	  get_number (1, 12, 2);
+	  tm->tm_mon = val - 1;
+	  have_mon = 1;
+	  want_xday = 1;
+	  break;
+	case 'M':
+	  /* Match minute.  */
+	  get_number (0, 59, 2);
+	  tm->tm_min = val;
+	  break;
+	case 'n':
+	case 't':
+	  /* Match any white space.  */
+	  while (isspace (*rp))
+	    ++rp;
+	  break;
+	case 'p':
+	  /* Match locale's equivalent of AM/PM.  */
+#ifdef _NL_CURRENT
+	  if (*decided != raw)
+	    {
+	      if (match_string (_NL_CURRENT (LC_TIME, AM_STR), rp))
+		{
+		  if (strcmp (_NL_CURRENT (LC_TIME, AM_STR), HERE_AM_STR))
+		    *decided = loc;
+		  break;
+		}
+	      if (match_string (_NL_CURRENT (LC_TIME, PM_STR), rp))
+		{
+		  if (strcmp (_NL_CURRENT (LC_TIME, PM_STR), HERE_PM_STR))
+		    *decided = loc;
+		  is_pm = 1;
+		  break;
+		}
+	      *decided = raw;
+	    }
+#endif
+	  if (!match_string (HERE_AM_STR, rp))
+	    if (match_string (HERE_PM_STR, rp))
+	      is_pm = 1;
+	    else
+	      return NULL;
+	  break;
+	case 'r':
+#ifdef _NL_CURRENT
+	  if (*decided != raw)
+	    {
+	      if (!recursive (_NL_CURRENT (LC_TIME, T_FMT_AMPM)))
+		{
+		  if (*decided == loc)
+		    return NULL;
+		  else
+		    rp = rp_backup;
+		}
+	      else
+		{
+		  if (*decided == not &&
+		      strcmp (_NL_CURRENT (LC_TIME, T_FMT_AMPM),
+			      HERE_T_FMT_AMPM))
+		    *decided = loc;
+		  break;
+		}
+	      *decided = raw;
+	    }
+#endif
+	  if (!recursive (HERE_T_FMT_AMPM))
+	    return NULL;
+	  break;
+	case 'R':
+	  if (!recursive ("%H:%M"))
+	    return NULL;
+	  break;
+	case 's':
+	  {
+	    /* The number of seconds may be very high so we cannot use
+	       the `get_number' macro.  Instead read the number
+	       character for character and construct the result while
+	       doing this.  */
+	    time_t secs = 0;
+	    if (*rp < '0' || *rp > '9')
+	      /* We need at least one digit.  */
+	      return NULL;
+
+	    do
+	      {
+		secs *= 10;
+		secs += *rp++ - '0';
+	      }
+	    while (*rp >= '0' && *rp <= '9');
+
+	    if (localtime_r (&secs, tm) == NULL)
+	      /* Error in function.  */
+	      return NULL;
+	  }
+	  break;
+	case 'S':
+	  get_number (0, 61, 2);
+	  tm->tm_sec = val;
+	  break;
+	case 'X':
+#ifdef _NL_CURRENT
+	  if (*decided != raw)
+	    {
+	      if (!recursive (_NL_CURRENT (LC_TIME, T_FMT)))
+		{
+		  if (*decided == loc)
+		    return NULL;
+		  else
+		    rp = rp_backup;
+		}
+	      else
+		{
+		  if (strcmp (_NL_CURRENT (LC_TIME, T_FMT), HERE_T_FMT))
+		    *decided = loc;
+		  break;
+		}
+	      *decided = raw;
+	    }
+#endif
+	  /* Fall through.  */
+	case 'T':
+	  if (!recursive (HERE_T_FMT))
+	    return NULL;
+	  break;
+	case 'u':
+	  get_number (1, 7, 1);
+	  tm->tm_wday = val % 7;
+	  have_wday = 1;
+	  break;
+	case 'g':
+	  get_number (0, 99, 2);
+	  /* XXX This cannot determine any field in TM.  */
+	  break;
+	case 'G':
+	  if (*rp < '0' || *rp > '9')
+	    return NULL;
+	  /* XXX Ignore the number since we would need some more
+	     information to compute a real date.  */
+	  do
+	    ++rp;
+	  while (*rp >= '0' && *rp <= '9');
+	  break;
+	case 'U':
+	case 'V':
+	case 'W':
+	  get_number (0, 53, 2);
+	  /* XXX This cannot determine any field in TM without some
+	     information.  */
+	  break;
+	case 'w':
+	  /* Match number of weekday.  */
+	  get_number (0, 6, 1);
+	  tm->tm_wday = val;
+	  have_wday = 1;
+	  break;
+	case 'y':
+#ifdef _NL_CURRENT
+	match_year_in_century:
+#endif
+	  /* Match year within century.  */
+	  get_number (0, 99, 2);
+	  /* The "Year 2000: The Millennium Rollover" paper suggests that
+	     values in the range 69-99 refer to the twentieth century.  */
+	  tm->tm_year = val >= 69 ? val : val + 100;
+	  /* Indicate that we want to use the century, if specified.  */
+	  want_century = 1;
+	  want_xday = 1;
+	  break;
+	case 'Y':
+	  /* Match year including century number.  */
+	  get_number (0, 9999, 4);
+	  tm->tm_year = val - 1900;
+	  want_century = 0;
+	  want_xday = 1;
+	  break;
+	case 'Z':
+	  /* XXX How to handle this?  */
+	  break;
+	case 'E':
+#ifdef _NL_CURRENT
+	  switch (*fmt++)
+	    {
+	    case 'c':
+	      /* Match locale's alternate date and time format.  */
+	      if (*decided != raw)
+		{
+		  const char *fmt = _NL_CURRENT (LC_TIME, ERA_D_T_FMT);
+
+		  if (*fmt == '\0')
+		    fmt = _NL_CURRENT (LC_TIME, D_T_FMT);
+
+		  if (!recursive (fmt))
+		    {
+		      if (*decided == loc)
+			return NULL;
+		      else
+			rp = rp_backup;
+		    }
+		  else
+		    {
+		      if (strcmp (fmt, HERE_D_T_FMT))
+			*decided = loc;
+		      want_xday = 1;
+		      break;
+		    }
+		  *decided = raw;
+		}
+	      /* The C locale has no era information, so use the
+		 normal representation.  */
+	      if (!recursive (HERE_D_T_FMT))
+		return NULL;
+	      want_xday = 1;
+	      break;
+	    case 'C':
+	      if (*decided != raw)
+		{
+		  if (era_cnt >= 0)
+		    {
+		      era = _nl_select_era_entry (era_cnt);
+		      if (match_string (era->era_name, rp))
+			{
+			  *decided = loc;
+			  break;
+			}
+		      else
+			return NULL;
+		    }
+		  else
+		    {
+		      num_eras = _NL_CURRENT_WORD (LC_TIME,
+						   _NL_TIME_ERA_NUM_ENTRIES);
+		      for (era_cnt = 0; era_cnt < (int) num_eras;
+			   ++era_cnt, rp = rp_backup)
+			{
+			  era = _nl_select_era_entry (era_cnt);
+			  if (match_string (era->era_name, rp))
+			    {
+			      *decided = loc;
+			      break;
+			    }
+			}
+		      if (era_cnt == (int) num_eras)
+			{
+			  era_cnt = -1;
+			  if (*decided == loc)
+			    return NULL;
+			}
+		      else
+			break;
+		    }
+
+		  *decided = raw;
+		}
+	      /* The C locale has no era information, so use the
+		 normal representation.  */
+	      goto match_century;
+ 	    case 'y':
+	      if (*decided == raw)
+		goto match_year_in_century;
+
+	      get_number(0, 9999, 4);
+	      tm->tm_year = val;
+	      want_era = 1;
+	      want_xday = 1;
+	      break;
+	    case 'Y':
+	      if (*decided != raw)
+		{
+		  num_eras = _NL_CURRENT_WORD (LC_TIME,
+					       _NL_TIME_ERA_NUM_ENTRIES);
+		  for (era_cnt = 0; era_cnt < (int) num_eras;
+		       ++era_cnt, rp = rp_backup)
+		    {
+		      era = _nl_select_era_entry (era_cnt);
+		      if (recursive (era->era_format))
+			break;
+		    }
+		  if (era_cnt == (int) num_eras)
+		    {
+		      era_cnt = -1;
+		      if (*decided == loc)
+			return NULL;
+		      else
+			rp = rp_backup;
+		    }
+		  else
+		    {
+		      *decided = loc;
+		      era_cnt = -1;
+		      break;
+		    }
+
+		  *decided = raw;
+		}
+	      get_number (0, 9999, 4);
+	      tm->tm_year = val - 1900;
+	      want_century = 0;
+	      want_xday = 1;
+	      break;
+	    case 'x':
+	      if (*decided != raw)
+		{
+		  const char *fmt = _NL_CURRENT (LC_TIME, ERA_D_FMT);
+
+		  if (*fmt == '\0')
+		    fmt = _NL_CURRENT (LC_TIME, D_FMT);
+
+		  if (!recursive (fmt))
+		    {
+		      if (*decided == loc)
+			return NULL;
+		      else
+			rp = rp_backup;
+		    }
+		  else
+		    {
+		      if (strcmp (fmt, HERE_D_FMT))
+			*decided = loc;
+		      break;
+		    }
+		  *decided = raw;
+		}
+	      if (!recursive (HERE_D_FMT))
+		return NULL;
+	      break;
+	    case 'X':
+	      if (*decided != raw)
+		{
+		  const char *fmt = _NL_CURRENT (LC_TIME, ERA_T_FMT);
+
+		  if (*fmt == '\0')
+		    fmt = _NL_CURRENT (LC_TIME, T_FMT);
+
+		  if (!recursive (fmt))
+		    {
+		      if (*decided == loc)
+			return NULL;
+		      else
+			rp = rp_backup;
+		    }
+		  else
+		    {
+		      if (strcmp (fmt, HERE_T_FMT))
+			*decided = loc;
+		      break;
+		    }
+		  *decided = raw;
+		}
+	      if (!recursive (HERE_T_FMT))
+		return NULL;
+	      break;
+	    default:
+	      return NULL;
+	    }
+	  break;
+#else
+	  /* We have no information about the era format.  Just use
+	     the normal format.  */
+	  if (*fmt != 'c' && *fmt != 'C' && *fmt != 'y' && *fmt != 'Y'
+	      && *fmt != 'x' && *fmt != 'X')
+	    /* This is an illegal format.  */
+	    return NULL;
+
+	  goto start_over;
+#endif
+	case 'O':
+	  switch (*fmt++)
+	    {
+	    case 'd':
+	    case 'e':
+	      /* Match day of month using alternate numeric symbols.  */
+	      get_alt_number (1, 31, 2);
+	      tm->tm_mday = val;
+	      have_mday = 1;
+	      want_xday = 1;
+	      break;
+	    case 'H':
+	      /* Match hour in 24-hour clock using alternate numeric
+		 symbols.  */
+	      get_alt_number (0, 23, 2);
+	      tm->tm_hour = val;
+	      have_I = 0;
+	      break;
+	    case 'I':
+	      /* Match hour in 12-hour clock using alternate numeric
+		 symbols.  */
+	      get_alt_number (1, 12, 2);
+	      tm->tm_hour = val - 1;
+	      have_I = 1;
+	      break;
+	    case 'm':
+	      /* Match month using alternate numeric symbols.  */
+	      get_alt_number (1, 12, 2);
+	      tm->tm_mon = val - 1;
+	      have_mon = 1;
+	      want_xday = 1;
+	      break;
+	    case 'M':
+	      /* Match minutes using alternate numeric symbols.  */
+	      get_alt_number (0, 59, 2);
+	      tm->tm_min = val;
+	      break;
+	    case 'S':
+	      /* Match seconds using alternate numeric symbols.  */
+	      get_alt_number (0, 61, 2);
+	      tm->tm_sec = val;
+	      break;
+	    case 'U':
+	    case 'V':
+	    case 'W':
+	      get_alt_number (0, 53, 2);
+	      /* XXX This cannot determine any field in TM without
+		 further information.  */
+	      break;
+	    case 'w':
+	      /* Match number of weekday using alternate numeric symbols.  */
+	      get_alt_number (0, 6, 1);
+	      tm->tm_wday = val;
+	      have_wday = 1;
+	      break;
+	    case 'y':
+	      /* Match year within century using alternate numeric symbols.  */
+	      get_alt_number (0, 99, 2);
+	      tm->tm_year = val >= 69 ? val : val + 100;
+	      want_xday = 1;
+	      break;
+	    default:
+	      return NULL;
+	    }
+	  break;
+	default:
+	  return NULL;
+	}
+    }
+
+  if (have_I && is_pm)
+    tm->tm_hour += 12;
+
+  if (century != -1)
+    {
+      if (want_century)
+	tm->tm_year = tm->tm_year % 100 + (century - 19) * 100;
+      else
+	/* Only the century, but not the year.  Strange, but so be it.  */
+	tm->tm_year = (century - 19) * 100;
+    }
+
+#ifdef _NL_CURRENT
+  if (era_cnt != -1)
+    {
+      era = _nl_select_era_entry(era_cnt);
+      if (want_era)
+	tm->tm_year = (era->start_date[0]
+		       + ((tm->tm_year - era->offset)
+			  * era->absolute_direction));
+      else
+	/* Era start year assumed.  */
+	tm->tm_year = era->start_date[0];
+    }
+  else
+#endif
+    if (want_era)
+      return NULL;
+
+  if (want_xday && !have_wday)
+    {
+      if ( !(have_mon && have_mday) && have_yday)
+	{
+	  /* We don't have tm_mon and/or tm_mday, compute them.  */
+	  int t_mon = 0;
+	  while (__mon_yday[__isleap(1900 + tm->tm_year)][t_mon] <= tm->tm_yday)
+	      t_mon++;
+	  if (!have_mon)
+	      tm->tm_mon = t_mon - 1;
+	  if (!have_mday)
+	      tm->tm_mday =
+		(tm->tm_yday
+		 - __mon_yday[__isleap(1900 + tm->tm_year)][t_mon - 1] + 1);
+	}
+      day_of_the_week (tm);
+    }
+  if (want_xday && !have_yday)
+    day_of_the_year (tm);
+
+  return (char *) rp;
+}
+
+
+char *
+strptime (buf, format, tm)
+     const char *buf;
+     const char *format;
+     struct tm *tm;
+{
+  enum locale_status decided;
+
+#ifdef _NL_CURRENT
+  decided = not;
+#else
+  decided = raw;
+#endif
+  return strptime_internal (buf, format, tm, &decided, -1);
+}

libav/strptime.h

+/* strptime.h
+ *
+ * $Id$
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * Copyright 1998 Gerald Combs
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef __STRPTIME_H__
+#define __STRPTIME_H__
+
+/*
+ * Version of "strptime()", for the benefit of OSes that don't have it.
+ */
+extern char *strptime(const char *, const char *, struct tm *);
+
+#endif