From: Jim Meyering Date: Mon, 2 Jun 2003 08:20:57 +0000 (+0000) Subject: Fix some minor time-related bugs with POSIX time arguments. X-Git-Tag: cvs-readonly~4843 X-Git-Url: http://erislabs.net/gitweb/?a=commitdiff_plain;h=b20a6a6e55940a5219dfe54a84f8a5abed5fa1b6;p=gnulib.git Fix some minor time-related bugs with POSIX time arguments. Some valid time stamps were being rejected (notably -1, and time stamps before 1900 on 64-bit hosts). And some invalid time stamps were being accepted, e.g. September 31. * posixtm.h (posixtime): Return bool instead of time_t, so that we can return (time_t) -1 successfully. * posixtm.c: Likewise. [HAVE_STDBOOL_H]: Include . (bool, false, true) [!HAVE_STDBOOL_H]: New type. (t): Remove static var. (year, posix_time_parse): Now takes struct tm * arg to modify, instead of static var. All uses changed. (year): Do not reject years before 1900; they can occur with 64-bit time_t. (posix_time_parse): Do not check for out-of-range components; that is now the caller's responsibility, since our checks were only approximations. (posixtime): Use mktime to check for out-of-range components, since it knows them exactly. If mktime returns (time_t) -1, check whether an error actually occurred by invoking localtime on -1. (main) [TEST_POSIXTIME]: Check for input data errors, and report posixtime failures better. Improve the test data (in comments only). --- diff --git a/lib/posixtm.c b/lib/posixtm.c index b09c03f1e..41c00ad67 100644 --- a/lib/posixtm.c +++ b/lib/posixtm.c @@ -22,6 +22,12 @@ # include #endif +#if HAVE_STDBOOL_H +# include +#else +typedef enum {false = 0, true = 1} bool; +#endif + #include #if HAVE_STDLIB_H # include @@ -51,9 +57,6 @@ of `digit' even when the host does not conform to POSIX. */ #define ISDIGIT(c) ((unsigned) (c) - '0' <= 9) -/* The return value. */ -static struct tm t; - time_t mktime (); /* @@ -74,26 +77,23 @@ time_t mktime (); */ static int -year (const int *digit_pair, size_t n, int allow_century) +year (struct tm *tm, const int *digit_pair, size_t n, int allow_century) { switch (n) { case 1: - t.tm_year = *digit_pair; + 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) - t.tm_year += 100; + tm->tm_year += 100; break; case 2: if (!allow_century) return 1; - t.tm_year = digit_pair[0] * 100 + digit_pair[1]; - if (t.tm_year < 1900) - return 1; - t.tm_year -= 1900; + tm->tm_year = digit_pair[0] * 100 + digit_pair[1] - 1900; break; case 0: @@ -104,7 +104,9 @@ year (const int *digit_pair, size_t n, int allow_century) /* Use current year. */ time (&now); tmp = localtime (&now); - t.tm_year = tmp->tm_year; + if (! tmp) + return 1; + tm->tm_year = tmp->tm_year; } break; @@ -116,7 +118,7 @@ year (const int *digit_pair, size_t n, int allow_century) } static int -posix_time_parse (const char *s, unsigned int syntax_bits) +posix_time_parse (struct tm *tm, const char *s, unsigned int syntax_bits) { const char *dot = NULL; int pair[6]; @@ -151,44 +153,30 @@ posix_time_parse (const char *s, unsigned int syntax_bits) p = pair; if (syntax_bits & PDS_LEADING_YEAR) { - if (year (p, len - 4, syntax_bits & PDS_CENTURY)) + if (year (tm, p, len - 4, syntax_bits & PDS_CENTURY)) return 1; p += len - 4; len = 4; } /* Handle 8 digits worth of `MMDDhhmm'. */ - if (*p < 1 || *p > 12) - return 1; - t.tm_mon = *p - 1; - ++p; --len; - - if (*p < 1 || *p > 31) - return 1; - t.tm_mday = *p; - ++p; --len; - - if (*p < 0 || *p > 23) - return 1; - t.tm_hour = *p; - ++p; --len; - - if (*p < 0 || *p > 59) - return 1; - t.tm_min = *p; - ++p; --len; + 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 (p, len, syntax_bits & PDS_CENTURY)) + if (year (tm, p, len, syntax_bits & PDS_CENTURY)) return 1; } /* Handle seconds. */ if (!dot) { - t.tm_sec = 0; + tm->tm_sec = 0; } else { @@ -199,34 +187,51 @@ posix_time_parse (const char *s, unsigned int syntax_bits) return 1; seconds = 10 * (dot[0] - '0') + dot[1] - '0'; - if (seconds < 0 || seconds > 61) - return 1; - t.tm_sec = seconds; + tm->tm_sec = seconds; } return 0; } -/* Parse a POSIX-style date and return it, or (time_t)-1 for an error. */ +/* Parse a POSIX-style date, returning true if successful. */ -time_t -posixtime (const char *s, unsigned int syntax_bits) +bool +posixtime (time_t *p, const char *s, unsigned int syntax_bits) { - t.tm_isdst = -1; - if (posix_time_parse (s, syntax_bits)) - return (time_t)-1; - else - return mktime (&t); -} + struct tm tm0; + struct tm tm1; + struct tm const *tm; + time_t t; -/* Parse a POSIX-style date and return it, or NULL for an error. */ + if (posix_time_parse (&tm0, s, syntax_bits)) + return false; -struct tm * -posixtm (const char *s, unsigned int syntax_bits) -{ - if (posixtime (s, syntax_bits) == -1) - return NULL; - return &t; + tm1 = tm0; + tm1.tm_isdst = -1; + t = mktime (&tm1); + + if (t != (time_t) -1) + tm = &tm1; + 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 @@ -234,20 +239,58 @@ posixtm (const char *s, unsigned int syntax_bits) 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 -1112131415 13 1323807300 Tue Dec 13 14:15:00 2011 -1112131415.16 13 1323807316 Tue Dec 13 14:15:16 2011 -201112131415.16 13 1323807316 Tue Dec 13 14:15:16 2011 -191112131415.16 13 -1 *** -203712131415.16 13 2144348116 Sun Dec 13 14:15:16 2037 -3712131415.16 13 2144348116 Sun Dec 13 14:15:16 2037 -6812131415.16 13 -1 *** -6912131415.16 13 -1 *** -7012131415.16 13 29967316 Sun Dec 13 14:15:16 1970 -12131415.16 13 913580116 Sun Dec 13 14:15:16 1998 - -1213141599 2 945116100 Mon Dec 13 14:15:00 1999 -1213141500 2 976738500 Wed Dec 13 14:15:00 2000 +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 */ @@ -265,13 +308,24 @@ main () char time_str[MAX_BUFF_LEN]; unsigned int syntax_bits; time_t t; - char *result; - sscanf (buff, "%s %u", time_str, &syntax_bits); - t = posixtime (time_str, syntax_bits); - result = (t == (time_t) -1 ? "***" : ctime (&t)); - printf ("%d %s\n", (int) t, result); + 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) t, ctime (&t)); + else + printf ("%12s %s", "*", "*\n"); + } } exit (0); } #endif + +/* +Local Variables: +compile-command: "gcc -DTEST_POSIXTIME -DHAVE_CONFIG_H -I.. -g -O -Wall -W posixtm.c" +End: +*/