From: Bruno Haible Date: Mon, 1 Sep 2003 17:47:35 +0000 (+0000) Subject: New module 'timegm'. X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=963409a8758faf2b24658c0a23cf0424211263d3;p=pspp New module 'timegm'. --- diff --git a/ChangeLog b/ChangeLog index a7020e2ca0..714da67116 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2003-08-31 Simon Josefsson + + * modules/timegm: New file. + * MODULES.html.sh (func_all_modules): Add timegm. + 2003-08-22 Simon Josefsson * modules/strndup (Makefile.am): Add strndup.h to lib_SOURCES. diff --git a/MODULES.html.sh b/MODULES.html.sh index 76b705e249..5b552b74a7 100755 --- a/MODULES.html.sh +++ b/MODULES.html.sh @@ -1533,6 +1533,7 @@ func_all_modules () func_begin_table func_module getdate + func_module timegm func_end_table element="Input/Output " diff --git a/lib/ChangeLog b/lib/ChangeLog index 82542c80a6..9f5c07ea7b 100644 --- a/lib/ChangeLog +++ b/lib/ChangeLog @@ -1,3 +1,8 @@ +2003-08-31 Simon Josefsson + + * timegm.h: New file. + * timegm.c: New file. Based on wget-1.8.2/src/http.c:mktime_from_utc. + 2003-08-31 Karl Berry * argp.h: update from libc. diff --git a/lib/timegm.c b/lib/timegm.c new file mode 100644 index 0000000000..a7b953da5b --- /dev/null +++ b/lib/timegm.c @@ -0,0 +1,96 @@ +/* Convert calendar time to simple time, inverse of mktime. + Copyright (C) 1995, 1996, 1997, 1998, 2000, 2001, 2003 + 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. */ + +#if HAVE_CONFIG_H +# include +#endif + +/* Specification. Get mktime and gmtime declarations. */ +#include "timegm.h" + +/* Converts struct tm to time_t, assuming the data in tm is UTC rather + than local timezone. + + mktime is similar but assumes struct tm, also known as the + "broken-down" form of time, is in local time zone. mktime_from_utc + uses mktime to make the conversion understanding that an offset + will be introduced by the local time assumption. + + mktime_from_utc then measures the introduced offset by applying + gmtime to the initial result and applying mktime to the resulting + "broken-down" form. The difference between the two mktime results + is the measured offset which is then subtracted from the initial + mktime result to yield a calendar time which is the value returned. + + tm_isdst in struct tm is set to 0 to force mktime to introduce a + consistent offset (the non DST offset) since tm and tm+o might be + on opposite sides of a DST change. + + Some implementations of mktime return -1 for the nonexistent + localtime hour at the beginning of DST. In this event, use + mktime(tm - 1hr) + 3600. + + Schematically + mktime(tm) --> t+o + gmtime(t+o) --> tm+o + mktime(tm+o) --> t+2o + t+o - (t+2o - t+o) = t + + Note that glibc contains a function of the same purpose named + `timegm' (reverse of gmtime). But obviously, it is not universally + available, and unfortunately it is not straightforwardly + extractable for use here. Perhaps configure should detect timegm + and use it where available. + + Contributed by Roger Beeman , with the help of + Mark Baushke and the rest of the Gurus at CISCO. + Further improved by Roger with assistance from Edward J. Sabol + based on input by Jamie Zawinski. */ + +time_t +timegm (struct tm *tm) +{ + time_t tl, tb; + struct tm *tg; + + tl = mktime (tm); + if (tl == (time_t) -1) + { + tm->tm_hour--; + tl = mktime (tm); + if (tl == (time_t) -1) + return (time_t) -1; + tl += 3600; + } +#if HAVE_GMTIME_R && HAVE_DECL_GMTIME_R + tg = gmtime_r (&tl, tg); +#else + tg = gmtime (&tl); +#endif + tg->tm_isdst = 0; + tb = mktime (tg); + if (tb == (time_t) -1) + { + tg->tm_hour--; + tb = mktime (tg); + if (tb == (time_t) -1) + return (time_t) -1; + tb += 3600; + } + return (tl - (tb - tl)); +} diff --git a/lib/timegm.h b/lib/timegm.h new file mode 100644 index 0000000000..18df9813e7 --- /dev/null +++ b/lib/timegm.h @@ -0,0 +1,31 @@ +/* Convert calendar time to simple time, inverse of mktime. + Copyright (C) 2003 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. */ + +#ifdef HAVE_TIMEGM + +/* Get timegm declaration. */ +#include + +#else + +/* Get time_t and struct tm. */ +#include + +/* Convert calendar time to simple time, inverse of mktime. */ +extern time_t timegm (struct tm *tm); + +#endif diff --git a/m4/ChangeLog b/m4/ChangeLog index d973385a7a..1e3ac030d8 100644 --- a/m4/ChangeLog +++ b/m4/ChangeLog @@ -1,3 +1,7 @@ +2003-08-31 Simon Josefsson + + * timegm.m4: New file. + 2003-08-26 Bruno Haible * fnmatch.m4 (_AC_LIBOBJ_FNMATCH): Remove AC_DEFINE of fnmatch here. diff --git a/m4/timegm.m4 b/m4/timegm.m4 new file mode 100644 index 0000000000..a0ba0e3a8a --- /dev/null +++ b/m4/timegm.m4 @@ -0,0 +1,25 @@ +# timegm.m4 serial 1 +dnl Copyright (C) 2003 Free Software Foundation, Inc. +dnl This file is free software, distributed under the terms of the GNU +dnl General Public License. As a special exception to the GNU General +dnl Public License, this file may be distributed as part of a program +dnl that contains a configuration script generated by Autoconf, under +dnl the same distribution terms as the rest of that program. + +AC_DEFUN([gl_FUNC_TIMEGM], +[ + AC_REPLACE_FUNCS(timegm) + if test $ac_cv_func_timegm = no; then + gl_PREREQ_TIMEGM + fi +]) + +# Prerequisites of lib/timegm.c. +AC_DEFUN([gl_PREREQ_TIMEGM], [ + AC_CHECK_DECLS(gmtime_r,,,[ +#ifdef HAVE_TIME_H +#include +#endif +]) + AC_CHECK_FUNCS(gmtime_r) +]) diff --git a/modules/timegm b/modules/timegm new file mode 100644 index 0000000000..34002c4cf3 --- /dev/null +++ b/modules/timegm @@ -0,0 +1,21 @@ +Description: +Convert calendar time to simple time, inverse of mktime. + +Files: +lib/timegm.h +lib/timegm.c +m4/timegm.m4 + +Depends-on: + +configure.ac: +gl_FUNC_TIMEGM + +Makefile.am: +lib_SOURCES += timegm.h + +Include: +"timegm.h" + +Maintainer: +Simon Josefsson