>From add5f660b7bd0cdb93ee36a941f151c615d4d5c3 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Tue, 28 Jul 2015 18:13:56 -0700 Subject: [PROPOSED PATCH 2/2] Port 'date' better to POSIX 1003.1-2001 and later * Makefile: Remove no-longer-needed comments. * NEWS, date.1: Document this. * date.c [HAVE_ADJTIME || HAVE_SETTIMEOFDAY]: Don't include sys/time.h. (main): Remove support for -a, -d, -t. (reset): Use clock_settime, not the nonstandard stime. (nondigit): Remove; no longer needed. * private.h (HAVE_ADJTIME, HAVE_SETTIMEOFDAY): Remove. --- Makefile | 5 --- NEWS | 8 ++++ date.1 | 34 ---------------- date.c | 130 +++++++++----------------------------------------------------- private.h | 10 +---- 5 files changed, 27 insertions(+), 160 deletions(-) diff --git a/Makefile b/Makefile index 8702119..09136f9 100644 --- a/Makefile +++ b/Makefile @@ -102,7 +102,6 @@ LDLIBS= # Add the following to the end of the "CFLAGS=" line as needed. # -DBIG_BANG=-9999999LL if the Big Bang occurred at time -9999999 (see zic.c) -# -DHAVE_ADJTIME=0 if 'adjtime' does not exist (SVR0?) # -DHAVE_DOS_FILE_NAMES if file names have drive specifiers etc. (MS-DOS) # -DHAVE_GETTEXT=1 if 'gettext' works (GNU, Linux, Solaris); also see LDLIBS # -DHAVE_INCOMPATIBLE_CTIME_R=1 if your system's time.h declares @@ -113,10 +112,6 @@ LDLIBS= # -DHAVE_LOCALTIME_RZ=0 if you do not want zdump to use localtime_rz # This defaults to 1 if a working localtime_rz seems to be available. # localtime_rz can make zdump significantly faster, but is nonstandard. -# -DHAVE_SETTIMEOFDAY=0 if settimeofday does not exist (SVR0?) -# -DHAVE_SETTIMEOFDAY=1 if settimeofday has just 1 arg (SVR4) -# -DHAVE_SETTIMEOFDAY=2 if settimeofday uses 2nd arg (4.3BSD) -# -DHAVE_SETTIMEOFDAY=3 if settimeofday ignores 2nd arg (4.4BSD) # -DHAVE_STDINT_H=1 if you have a pre-C99 compiler with "stdint.h" # -DHAVE_STRFTIME_L=1 if declares locale_t and strftime_l # This defaults to 0 if _POSIX_VERSION < 200809, 1 otherwise. diff --git a/NEWS b/NEWS index 45065e4..e6ece37 100644 --- a/NEWS +++ b/NEWS @@ -48,6 +48,14 @@ Unreleased, experimental changes Some Visual Studio 2013 warnings have been suppressed. (Thanks to Kees Dekker.) + date now sets the time of day via the POSIX clock_settime function + instead of via the older nonstandard settimeofday function. + date's -a, -d, and -t options have been removed. Long obsolescent, + they were usable only by the superuser, and their implementation + had porting problems. Builders no longer need to configure + HAVE_ADJTIME and HAVE_SETTIMEOFDAY. (Thanks to Kees Dekker for + pointing out the problem.) + The implementation of date's -n option, which has long been a no-op in practice, has been greatly simplified and the -n option is no longer documented. (Thanks to Kees Dekker for pointing out diff --git a/date.1 b/date.1 index 567c636..7fd4848 100644 --- a/date.1 +++ b/date.1 @@ -15,14 +15,6 @@ date \- show and set date and time .B \*-r .I seconds ] [ -.B \*-d -.I dsttype -] [ -.B \*-t -.I minutes-west -] [ -\fB\*-a \fR[\fB+\fR|\fB\*-]\fIsss\fB.\fIfff\fR -] [ .BI + format ] [ \fR[\fIyyyy\fR]\fImmddhhmm\fR[\fIyy\fR][\fB.\fIss\fR] @@ -151,32 +143,6 @@ past the epoch of 1970-01-01 00:00:00 UTC, where .I seconds should be an integer, either decimal, octal (leading 0), or hexadecimal (leading 0x), preceded by an optional sign. -.TP -.BI "\*-d " dsttype -Set the kernel-stored Daylight Saving Time type to the given value. -(The kernel-stored DST type is used mostly by -.q "old" -binaries.) -.TP -.BI "\*-t " minutes-west -Set the kernel-stored -.q "minutes west of UTC" -value to the one given on the -command line. -(The kernel-stored DST type is used mostly by -.q "old" -binaries.) -.TP -.BI "\*-a " adjustment -Change the time forward (or backward) by the number of seconds -(and fractions thereof) specified in the -.I adjustment -argument. -Either the seconds part or the fractions part of the argument (but not both) -may be omitted. -On BSD-based systems, -the adjustment is made by changing the rate at which time advances; -on System-V-based systems, the adjustment is made by changing the time. .SH FILES .ta \w'/usr/local/etc/zoneinfo/posixrules\0\0'u /usr/lib/locale/\f2L\fP/LC_TIME description of time locale \f2L\fP diff --git a/date.c b/date.c index 2a55505..a273f81 100644 --- a/date.c +++ b/date.c @@ -16,9 +16,6 @@ */ #include "private.h" -#if HAVE_ADJTIME || HAVE_SETTIMEOFDAY -#include "sys/time.h" /* for struct timeval, struct timezone */ -#endif /* HAVE_ADJTIME || HAVE_SETTIMEOFDAY */ #include "locale.h" #if HAVE_UTMPX_H #include "utmpx.h" @@ -59,7 +56,6 @@ static void display(const char *, time_t); static void dogmt(void); static void errensure(void); static void iffy(time_t, time_t, const char *, const char *); -static const char * nondigit(const char *); static void oops(const char *); static void reset(time_t); static void timeout(FILE *, const char *, const struct tm *); @@ -75,13 +71,7 @@ main(const int argc, char *argv[]) register const char * cp; register int ch; register bool dousg; - register bool aflag = false; - register bool dflag = false; - register bool tflag = false; register bool rflag = false; - register int minuteswest; - register int dsttime; - register double adjust; time_t now; time_t t; intmax_t secs; @@ -99,7 +89,7 @@ main(const int argc, char *argv[]) #endif /* HAVE_GETTEXT */ t = now = time(NULL); format = value = NULL; - while ((ch = getopt(argc, argv, "ucr:nd:t:a:")) != EOF && ch != -1) { + while ((ch = getopt(argc, argv, "ucr:n")) != EOF && ch != -1) { switch (ch) { default: usage(); @@ -129,55 +119,6 @@ main(const int argc, char *argv[]) break; case 'n': /* don't set network (ignored) */ break; - case 'd': /* daylight saving time */ - if (dflag) { - fprintf(stderr, - _("date: error: multiple -d's used")); - usage(); - } - dflag = true; - cp = optarg; - dsttime = atoi(cp); - if (*cp == '\0' || *nondigit(cp) != '\0') - wildinput(_("-t value"), optarg, - _("must be a non-negative number")); - break; - case 't': /* minutes west of UTC */ - if (tflag) { - fprintf(stderr, - _("date: error: multiple -t's used")); - usage(); - } - tflag = true; - cp = optarg; - minuteswest = atoi(cp); - if (*cp == '+' || *cp == '-') - ++cp; - if (*cp == '\0' || *nondigit(cp) != '\0') - wildinput(_("-d value"), optarg, - _("must be a number")); - break; - case 'a': /* adjustment */ - if (aflag) { - fprintf(stderr, - _("date: error: multiple -a's used")); - usage(); - } - aflag = true; - cp = optarg; - adjust = atof(cp); - if (*cp == '+' || *cp == '-') - ++cp; - if (*cp == '\0' || strcmp(cp, ".") == 0) - wildinput(_("-a value"), optarg, - _("must be a number")); - cp = nondigit(cp); - if (*cp == '.') - ++cp; - if (*nondigit(cp) != '\0') - wildinput(_("-a value"), optarg, - _("must be a number")); - break; } } while (optind < argc) { @@ -240,44 +181,6 @@ _("date: error: multiple values in command line\n")); /* ** Entire command line has now been checked. */ - if (aflag) { -#if HAVE_ADJTIME - struct timeval tv; - - tv.tv_sec = (int) adjust; - tv.tv_usec = (int) ((adjust - tv.tv_sec) * 1000000L); - if (adjtime(&tv, NULL) != 0) - oops("adjtime"); -#endif /* HAVE_ADJTIME */ -#if !HAVE_ADJTIME - reset(now + adjust); -#endif /* !HAVE_ADJTIME */ - /* - ** Sun silently ignores everything else; we follow suit. - */ - exit(retval); - } - if (dflag || tflag) { -#if HAVE_SETTIMEOFDAY == 2 - struct timezone tz; - - if (!dflag || !tflag) - if (gettimeofday(NULL, &tz) != 0) - oops("gettimeofday"); - if (dflag) - tz.tz_dsttime = dsttime; - if (tflag) - tz.tz_minuteswest = minuteswest; - if (settimeofday(NULL, &tz) != 0) - oops("settimeofday"); -#endif /* HAVE_SETTIMEOFDAY == 2 */ -#if HAVE_SETTIMEOFDAY != 2 - (void) dsttime; - (void) minuteswest; - fprintf(stderr, -_("date: warning: kernel doesn't keep -d/-t information, option ignored\n")); -#endif /* HAVE_SETTIMEOFDAY != 2 */ - } if (value) { reset(t); @@ -320,7 +223,8 @@ dogmt(void) /* ** We assume we're on a POSIX-based system, -** should use stime, and should write utmp entries if HAVE_UTMPX_H, +** should use clock_settime if CLOCK_REALTIME is defined, +** and should write utmp entries if HAVE_UTMPX_H, ** and don't have network notification to worry about. */ @@ -342,10 +246,21 @@ reset(time_t newt) #endif /* - ** Wouldn't it be great if stime returned the old time? + ** Wouldn't it be great if clock_settime returned the old time? */ - if (stime(&newt) != 0) - oops("stime"); + int clock_settime_result; +#ifdef CLOCK_REALTIME + struct timespec ts; + ts.tv_sec = newt; + ts.tv_nsec = 0; + clock_settime_result = clock_settime(CLOCK_REALTIME, &ts); +#else + clock_settime_result = -1; + errno = EPERM; +#endif + if (clock_settime_result != 0) + oops("clock_settime"); + #if HAVE_UTMPX_H sx.before.ut_type = OLD_TIME; sx.before.ut_tv.tv_sec = oldt; @@ -388,20 +303,11 @@ errensure(void) retval = EXIT_FAILURE; } -static const char * ATTRIBUTE_PURE -nondigit(register const char *cp) -{ - while (is_digit(*cp)) - ++cp; - return cp; -} - static void usage(void) { fprintf(stderr, _("date: usage: date [-u] [-c] [-r seconds]" - " [-d dst] [-t min-west] [-a sss.fff]" " [[yyyy]mmddhhmm[yyyy][.ss]] [+format]\n")); errensure(); exit(retval); @@ -644,7 +550,7 @@ checkfinal(char const *value, bool didusg, time_t t, time_t oldnow) ** So we perform this final check, deferring it until after the time has ** been set; it may take a while, and we don't want to introduce an unnecessary ** lag between the time the user enters their command and the time that -** stime/settimeofday is called. +** clock_settime is called. ** ** We just check nearby times to see if any have the same representation ** as the time that convert returned. We work our way out from the center diff --git a/private.h b/private.h index 71a02d8..184da8f 100644 --- a/private.h +++ b/private.h @@ -19,13 +19,9 @@ /* ** Defaults for preprocessor symbols. -** You can override these in your C compiler options, e.g. '-DHAVE_ADJTIME=0'. +** You can override these in your C compiler options, e.g. '-DHAVE_GETTEXT=1'. */ -#ifndef HAVE_ADJTIME -#define HAVE_ADJTIME 1 -#endif /* !defined HAVE_ADJTIME */ - #ifndef HAVE_GETTEXT #define HAVE_GETTEXT 0 #endif /* !defined HAVE_GETTEXT */ @@ -38,10 +34,6 @@ #define HAVE_LINK 1 #endif /* !defined HAVE_LINK */ -#ifndef HAVE_SETTIMEOFDAY -#define HAVE_SETTIMEOFDAY 3 -#endif /* !defined HAVE_SETTIMEOFDAY */ - #ifndef HAVE_STRDUP #define HAVE_STRDUP 1 #endif -- 2.1.4