From c0ad97a7817a05f23a303a5545ff49a7f62cafbd Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Sun, 6 Sep 1998 22:57:00 +0000 Subject: rewrite from yacc-based version --- lib/posixtm.c | 215 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 215 insertions(+) create mode 100644 lib/posixtm.c (limited to 'lib/posixtm.c') diff --git a/lib/posixtm.c b/lib/posixtm.c new file mode 100644 index 000000000..699305049 --- /dev/null +++ b/lib/posixtm.c @@ -0,0 +1,215 @@ +/* Parse dates for touch. + Copyright (C) 1989, 1990, 1991, 1998 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 2, 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. */ + +/* Yacc-based version written by Jim Kingdon and David MacKenzie. + Rewritten by Jim Meyering. */ + +#ifdef HAVE_CONFIG_H +# include +#endif + +#include +#include + +#ifdef TM_IN_SYS_TIME +# include +#else +# include +#endif + +/* The return value. */ +static struct tm t; + +time_t mktime (); + +/* + 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... + 8 or 10 digits + (PDS_TRAILING_YEAR) + + date mmddhhmm[[CC]YY] + 8, 10, or 12 digits + (PDS_TRAILING_YEAR | PDS_CENTURY) + +*/ + +/* FIXME: put these in posixtm.h */ +/* POSIX Date Syntax flags. */ +#define PDS_LEADING_YEAR 1 +#define PDS_TRAILING_YEAR 2 +#define PDS_CENTURY 4 +#define PDS_SECONDS 8 + +static int +year (const int *digit_pair, size_t n, int allow_century) +{ + switch (n) + { + case 1: + t.tm_year = *digit_pair; + /* Deduce the century based on the year. + See POSIX.2 section 4.63.3. */ + if (digit_pair[0] <= 68) + t.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; + break; + + case 0: + { + time_t now; + struct tm *tmp; + + /* Use current year. */ + time (&now); + tmp = localtime (&now); + t.tm_year = tmp->tm_year; + } + break; + + default: + abort (); + } + + return 0; +} + +static int +posix_time_parse (const char *s, unsigned int syntax_bits) +{ + const char *dot; + int pair[6]; + int *p; + int i; + + size_t s_len = strlen (s); + size_t len = (((syntax_bits & PDS_SECONDS) && (dot = strchr (s, '.'))) + ? 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 (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; + + /* Handle any trailing year. */ + if (syntax_bits & PDS_TRAILING_YEAR) + { + if (year (p, len, syntax_bits & PDS_CENTURY)) + return 1; + } + + /* Handle seconds. */ + if (!dot) + { + t.tm_sec = 0; + } + else + { + int seconds; + + ++dot; + if (!ISDIGIT (dot[0]) || !ISDIGIT (dot[1])) + return 1; + seconds = 10 * (dot[0] - '0') + dot[1] - '0'; + + if (seconds < 0 || seconds > 61) + return 1; + t.tm_sec = seconds; + } + + return 0; +} + +/* Parse a POSIX-style date and return it, or (time_t)-1 for an error. */ + +struct tm * +posixtime (const char *s) +{ + t.tm_isdst = -1; + if (posix_time_parse (s)) + return (time_t)-1; + else + return mktime (&t); +} + +/* Parse a POSIX-style date and return it, or NULL for an error. */ + +struct tm * +posixtm (const char *s) +{ + if (posixtime (s) == -1) + return NULL; + return &t; +} -- cgit v1.2.3-54-g00ecf