/*

 * This file is taken from coreutils 7.4

 */

/* Parse dates for touch and date.

   Copyright (C) 1989, 1990, 1991, 1998, 2000, 2001, 2002, 2003, 2004,

   2005, 2006, 2007 Free Software Foundation Inc.

   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 3 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, see <http://www.gnu.org/licenses/>.  */

/* Yacc-based version written by Jim Kingdon and David MacKenzie.

   Rewritten by Jim Meyering.  */

#include <config.h>

#include "posixtm.h"

#include <stdio.h>

#include <stdlib.h>

#include <sys/types.h>

#include <string.h>

#if USE_UNLOCKED_IO

# include "unlocked-io.h"

#endif

/* ISDIGIT differs from isdigit, as follows:

   - Its arg may be any int or unsigned int; it need not be an unsigned char

     or EOF.

   - It's typically faster.

   POSIX says that only '0' through '9' are digits.  Prefer ISDIGIT to

   isdigit unless it's important to use the locale's definition

   of `digit' even when the host does not conform to POSIX.  */

#define ISDIGIT(c) ((unsigned int) (c) - '0' <= 9)

/*

  POSIX requires:

  touch -t [[CC]YY]mmddhhmm[.ss] FILE...

    8, 10, or 12 digits, followed by optional .ss

    (PDS_LEADING_YEAR | PDS_CENTURY | PDS_SECONDS)

  touch mmddhhmm[YY] FILE... (obsoleted by POSIX 1003.1-2001)

    8 or 10 digits, YY (if present) must be in the range 69-99

    (PDS_TRAILING_YEAR | PDS_PRE_2000)

  date mmddhhmm[[CC]YY]

    8, 10, or 12 digits

    (PDS_TRAILING_YEAR | PDS_CENTURY)

*/

static int

year (struct tm *tm, const int *digit_pair, size_t n, unsigned int syntax_bits)

{

  switch (n)

    {

    case 1:

      tm->tm_year = *digit_pair;

      /* Deduce the century based on the year.

	 POSIX requires that 00-68 be interpreted as 2000-2068,

	 and that 69-99 be interpreted as 1969-1999.  */

      if (digit_pair[0] <= 68)

	{

	  if (syntax_bits & PDS_PRE_2000)

	    return 1;

	  tm->tm_year += 100;

	}

      break;

    case 2:

      if (! (syntax_bits & PDS_CENTURY))

	return 1;

      tm->tm_year = digit_pair[0] * 100 + digit_pair[1] - 1900;

      break;

    case 0:

      {

	time_t now;

	struct tm *tmp;

	/* Use current year.  */

	time (&now;;

	tmp = localtime (&now;;

	if (! tmp)

	  return 1;

	tm->tm_year = tmp->tm_year;

      }

      break;

    default:

      abort ();

    }

  return 0;

}

static int

posix_time_parse (struct tm *tm, const char *s, unsigned int syntax_bits)

{

  const char *dot = NULL;

  int pair[6];

  int *p;

  size_t i;

  size_t s_len = strlen (s);

  size_t len = (((syntax_bits & PDS_SECONDS) && (dot = strchr (s, '.')))

		? (size_t) (dot - s)

		: s_len);

  if (len != 8 && len != 10 && len != 12)

    return 1;

  if (dot)

    {

      if (!(syntax_bits & PDS_SECONDS))

	return 1;

      if (s_len - len != 3)

	return 1;

    }

  for (i = 0; i < len; i++)

    if (!ISDIGIT (s[i]))

      return 1;

  len /= 2;

  for (i = 0; i < len; i++)

    pair[i] = 10 * (s[2*i] - '0') + s[2*i + 1] - '0';

  p = pair;

  if (syntax_bits & PDS_LEADING_YEAR)

    {

      if (year (tm, p, len - 4, syntax_bits))

	return 1;

      p += len - 4;

      len = 4;

    }

  /* Handle 8 digits worth of `MMDDhhmm'.  */

  tm->tm_mon = *p++ - 1;

  tm->tm_mday = *p++;

  tm->tm_hour = *p++;

  tm->tm_min = *p++;

  len -= 4;

  /* Handle any trailing year.  */

  if (syntax_bits & PDS_TRAILING_YEAR)

    {

      if (year (tm, p, len, syntax_bits))

	return 1;

    }

  /* Handle seconds.  */

  if (!dot)

    {

      tm->tm_sec = 0;

    }

  else

    {

      int seconds;

      ++dot;

      if (!ISDIGIT (dot[0]) || !ISDIGIT (dot[1]))

	return 1;

      seconds = 10 * (dot[0] - '0') + dot[1] - '0';

      tm->tm_sec = seconds;

    }

  return 0;

}

/* Parse a POSIX-style date, returning true if successful.  */

bool

posixtime (time_t *p, const char *s, unsigned int syntax_bits)

{

  struct tm tm0;

  struct tm tm1;

  struct tm const *tm;

  time_t t;

  if (posix_time_parse (&tm0, s, syntax_bits))

    return false;

  tm1 = tm0;

  tm1.tm_isdst = -1;

  t = mktime (&tm1);

  if (t != (time_t) -1)

    tm = &tm;;

  else

    {

      /* mktime returns -1 for errors, but -1 is also a valid time_t

	 value.  Check whether an error really occurred.  */

      tm = localtime (&t);

      if (! tm)

	return false;

    }

  /* Reject dates like "September 31" and times like "25:61".  */

  if ((tm0.tm_year ^ tm->tm_year)

      | (tm0.tm_mon ^ tm->tm_mon)

      | (tm0.tm_mday ^ tm->tm_mday)

      | (tm0.tm_hour ^ tm->tm_hour)

      | (tm0.tm_min ^ tm->tm_min)

      | (tm0.tm_sec ^ tm->tm_sec))

    return false;

  *p = t;

  return true;

}

#ifdef TEST_POSIXTIME

/*

    Test mainly with syntax_bits == 13

    (aka: (PDS_LEADING_YEAR | PDS_CENTURY | PDS_SECONDS))

    This test data assumes Universal Time, e.g., TZ="UTC0".

    This test data also assumes that time_t is signed and is at least

    39 bits wide, so that it can represent all years from 0000 through

    9999.  A host with 32-bit signed time_t can represent only time

    stamps in the range 1901-12-13 20:45:52 through 2038-01-18

    03:14:07 UTC, assuming POSIX time_t with no leap seconds, so test

    cases outside this range will not work on such a host.

    Also, the first two lines of test data assume that the current

    year is 2002.

BEGIN-DATA

12131415.16     13   1039788916 Fri Dec 13 14:15:16 2002

12131415.16     13   1039788916 Fri Dec 13 14:15:16 2002

000001010000.00 13 -62167132800 Sun Jan  1 00:00:00 0000

190112132045.52 13  -2147483648 Fri Dec 13 20:45:52 1901

190112132045.53 13  -2147483647 Fri Dec 13 20:45:53 1901

190112132046.52 13  -2147483588 Fri Dec 13 20:46:52 1901

190112132145.52 13  -2147480048 Fri Dec 13 21:45:52 1901

190112142045.52 13  -2147397248 Sat Dec 14 20:45:52 1901

190201132045.52 13  -2144805248 Mon Jan 13 20:45:52 1902

196912312359.59 13           -1 Wed Dec 31 23:59:59 1969

197001010000.00 13            0 Thu Jan  1 00:00:00 1970

197001010000.01 13            1 Thu Jan  1 00:00:01 1970

197001010001.00 13           60 Thu Jan  1 00:01:00 1970

197001010100.00 13         3600 Thu Jan  1 01:00:00 1970

197001020000.00 13        86400 Fri Jan  2 00:00:00 1970

197002010000.00 13      2678400 Sun Feb  1 00:00:00 1970

197101010000.00 13     31536000 Fri Jan  1 00:00:00 1971

197001000000.00 13            * *

197000010000.00 13            * *

197001010000.60 13            * *

197001010060.00 13            * *

197001012400.00 13            * *

197001320000.00 13            * *

197013010000.00 13            * *

203801190314.06 13   2147483646 Tue Jan 19 03:14:06 2038

203801190314.07 13   2147483647 Tue Jan 19 03:14:07 2038

203801190314.08 13   2147483648 Tue Jan 19 03:14:08 2038

999912312359.59 13 253402300799 Fri Dec 31 23:59:59 9999

1112131415      13   1323785700 Tue Dec 13 14:15:00 2011

1112131415.16   13   1323785716 Tue Dec 13 14:15:16 2011

201112131415.16 13   1323785716 Tue Dec 13 14:15:16 2011

191112131415.16 13  -1831974284 Wed Dec 13 14:15:16 1911

203712131415.16 13   2144326516 Sun Dec 13 14:15:16 2037

3712131415.16   13   2144326516 Sun Dec 13 14:15:16 2037

6812131415.16   13   3122633716 Thu Dec 13 14:15:16 2068

6912131415.16   13     -1590284 Sat Dec 13 14:15:16 1969

7012131415.16   13     29945716 Sun Dec 13 14:15:16 1970

1213141599       2    945094500 Mon Dec 13 14:15:00 1999

1213141500       2    976716900 Wed Dec 13 14:15:00 2000

END-DATA

*/

# define MAX_BUFF_LEN 1024

int

main (void)

{

  char buff[MAX_BUFF_LEN + 1];

  buff[MAX_BUFF_LEN] = 0;

  while (fgets (buff, MAX_BUFF_LEN, stdin) && buff[0])

    {

      char time_str[MAX_BUFF_LEN];

      unsigned int syntax_bits;

      time_t t;

      if (sscanf (buff, "%s %u", time_str, &syntax_bits) != 2)

	printf ("*\n");

      else

	{

	  printf ("%-15s %2u ", time_str, syntax_bits);

	  if (posixtime (&t, time_str, syntax_bits))

	    printf ("%12ld %s", (long int) t, ctime (&t);;

	  else

	    printf ("%12s %s", "*", "*\n");

	}

    }

  exit (0);

}

#endif

/*

Local Variables:

compile-command: "gcc -DTEST_POSIXTIME -g -O -Wall -W posixtm.c"

End:

*/