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Diffstat (limited to 'libmisc/strtoday.c')
| -rw-r--r-- | libmisc/strtoday.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/libmisc/strtoday.c b/libmisc/strtoday.c new file mode 100644 index 0000000..d321873 --- /dev/null +++ b/libmisc/strtoday.c @@ -0,0 +1,220 @@ +/* + * SPDX-FileCopyrightText: 1991 - 1994, Julianne Frances Haugh + * SPDX-FileCopyrightText: 1996 - 1999, Marek Michałkiewicz + * SPDX-FileCopyrightText: 2003 - 2005, Tomasz Kłoczko + * SPDX-FileCopyrightText: 2008 , Nicolas François + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#if !defined(__GLIBC__) +#define _XOPEN_SOURCE 500 +#endif + +#include <config.h> + +#include <ctype.h> + +#ident "$Id$" + +#include "defines.h" +#include "prototypes.h" + +#ifndef USE_GETDATE +#define USE_GETDATE 1 +#endif + +#if USE_GETDATE +#include "getdate.h" +/* + * strtoday() now uses get_date() (borrowed from GNU shellutils) + * which can handle many date formats, for example: + * 1970-09-17 # ISO 8601. + * 70-9-17 # This century assumed by default. + * 70-09-17 # Leading zeros are ignored. + * 9/17/72 # Common U.S. writing. + * 24 September 1972 + * 24 Sept 72 # September has a special abbreviation. + * 24 Sep 72 # Three-letter abbreviations always allowed. + * Sep 24, 1972 + * 24-sep-72 + * 24sep72 + */ +long strtoday (const char *str) +{ + time_t t; + bool isnum = true; + const char *s = str; + + /* + * get_date() interprets an empty string as the current date, + * which is not what we expect, unless you're a BOFH :-). + * (useradd sets sp_expire = current date for new lusers) + */ + if ((NULL == str) || ('\0' == *str)) { + return -1; + } + + /* If a numerical value is provided, this is already a number of + * days since EPOCH. + */ + if ('-' == *s) { + s++; + } + while (' ' == *s) { + s++; + } + while (isnum && ('\0' != *s)) { + if (!isdigit (*s)) { + isnum = false; + } + s++; + } + if (isnum) { + long retdate; + if (getlong (str, &retdate) == 0) { + return -2; + } + return retdate; + } + + t = get_date (str, NULL); + if ((time_t) - 1 == t) { + return -2; + } + /* convert seconds to days since 1970-01-01 */ + return (long) (t + DAY / 2) / DAY; +} + +#else /* !USE_GETDATE */ +/* + * Old code, just in case get_date() doesn't work as expected... + */ +#include <stdio.h> +#ifdef HAVE_STRPTIME +/* + * for now we allow just one format, but we can define more later + * (we try them all until one succeeds). --marekm + */ +static const char *const date_formats[] = { + "%Y-%m-%d", + (char *) 0 +}; +#else +/* + * days and juldays are used to compute the number of days in the + * current month, and the cumulative number of days in the preceding + * months. they are declared so that january is 1, not 0. + */ +static const short days[13] = { 0, + 31, 28, 31, 30, 31, 30, /* JAN - JUN */ + 31, 31, 30, 31, 30, 31 +}; /* JUL - DEC */ + +static const short juldays[13] = { 0, + 0, 31, 59, 90, 120, 151, /* JAN - JUN */ + 181, 212, 243, 273, 304, 334 +}; /* JUL - DEC */ +#endif + +/* + * strtoday - compute the number of days since 1970. + * + * the total number of days prior to the current date is + * computed. january 1, 1970 is used as the origin with + * it having a day number of 0. + */ + +long strtoday (const char *str) +{ +#ifdef HAVE_STRPTIME + struct tm tp; + const char *const *fmt; + char *cp; + time_t result; + + memzero (&tp, sizeof tp); + for (fmt = date_formats; *fmt; fmt++) { + cp = strptime ((char *) str, *fmt, &tp); + if ((NULL == cp) || ('\0' != *cp)) { + continue; + } + + result = mktime (&tp); + if ((time_t) - 1 == result) { + continue; + } + + return (long) (result / DAY); /* success */ + } + return -1; +#else + char slop[2]; + int month; + int day; + int year; + long total; + + /* + * start by separating the month, day and year. the order + * is compiled in ... + */ + + if (sscanf (str, "%d/%d/%d%c", &year, &month, &day, slop) != 3) { + return -1; + } + + /* + * the month, day of the month, and year are checked for + * correctness and the year adjusted so it falls between + * 1970 and 2069. + */ + + if ((month < 1) || (month > 12)) { + return -1; + } + + if (day < 1) { + return -1; + } + + if ( ((2 != month) || ((year % 4) != 0)) + && (day > days[month])) { + return -1; + } else if ((month == 2) && ((year % 4) == 0) && (day > 29)) { + return -1; + } + + if (year < 0) { + return -1; + } else if (year <= 69) { + year += 2000; + } else if (year <= 99) { + year += 1900; + } + + /* + * On systems with 32-bit signed time_t, time wraps around in 2038 + * - for now we just limit the year to 2037 (instead of 2069). + * This limit can be removed once no one is using 32-bit systems + * anymore :-). --marekm + */ + if ((year < 1970) || (year > 2037)) { + return -1; + } + + /* + * the total number of days is the total number of days in all + * the whole years, plus the number of leap days, plus the + * number of days in the whole months preceding, plus the number + * of days so far in the month. + */ + + total = (long) ((year - 1970) * 365L) + (((year + 1) - 1970) / 4); + total += (long) juldays[month] + (month > 2 && (year % 4) == 0 ? 1 : 0); + total += (long) day - 1; + + return total; +#endif /* HAVE_STRPTIME */ +} +#endif /* !USE_GETDATE */ |