From 9fe1548bbfde548d54acaab113656a56ea0ccc72 Mon Sep 17 00:00:00 2001 From: Ron Yorston Date: Thu, 16 Sep 2021 10:26:14 +0100 Subject: date,touch: allow timezone offsets in dates Allow ISO 8601 style dates to include a timezone offset. Like the '@' format these dates aren't relative to the user's current timezone and shouldn't be subject to DST adjustment. - The implementation uses the strptime() '%z' format specifier. This an extension which may not be available so the use of timezones is a configuration option. - The 'touch' applet has been updated to respect whether DST adjustment is required, matching 'date'. function old new delta parse_datestr 624 730 +106 static.fmt_str 106 136 +30 touch_main 388 392 +4 date_main 818 819 +1 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 4/0 up/down: 141/0) Total: 141 bytes Signed-off-by: Ron Yorston Signed-off-by: Denys Vlasenko --- coreutils/date.c | 7 ++++--- coreutils/touch.c | 6 ++++-- include/libbb.h | 2 +- libbb/Config.src | 11 +++++++++++ libbb/time.c | 35 +++++++++++++++++++++++++++++++---- testsuite/date/date-timezone | 32 ++++++++++++++++++++++++++++++++ 6 files changed, 83 insertions(+), 10 deletions(-) create mode 100644 testsuite/date/date-timezone diff --git a/coreutils/date.c b/coreutils/date.c index 7061f17..abcc37c 100644 --- a/coreutils/date.c +++ b/coreutils/date.c @@ -266,6 +266,7 @@ int date_main(int argc UNUSED_PARAM, char **argv) /* If date string is given, update tm_time, and maybe set date */ if (date_str != NULL) { + int check_dst = 1; /* Zero out fields - take her back to midnight! */ tm_time.tm_sec = 0; tm_time.tm_min = 0; @@ -276,12 +277,12 @@ int date_main(int argc UNUSED_PARAM, char **argv) if (strptime(date_str, fmt_str2dt, &tm_time) == NULL) bb_error_msg_and_die(bb_msg_invalid_date, date_str); } else { - parse_datestr(date_str, &tm_time); + check_dst = parse_datestr(date_str, &tm_time); } /* Correct any day of week and day of year etc. fields */ - /* Be sure to recheck dst (but not if date is time_t format) */ - if (date_str[0] != '@') + /* Be sure to recheck dst (but not if date is UTC) */ + if (check_dst) tm_time.tm_isdst = -1; ts.tv_sec = validate_tm_time(date_str, &tm_time); ts.tv_nsec = 0; diff --git a/coreutils/touch.c b/coreutils/touch.c index 78100ba..7e13a27 100644 --- a/coreutils/touch.c +++ b/coreutils/touch.c @@ -140,15 +140,17 @@ int touch_main(int argc UNUSED_PARAM, char **argv) if (opts & (OPT_d|OPT_t)) { struct tm tm_time; time_t t; + int check_dst; //memset(&tm_time, 0, sizeof(tm_time)); /* Better than memset: makes "HH:MM" dates meaningful */ time(&t); localtime_r(&t, &tm_time); - parse_datestr(date_str, &tm_time); + check_dst = parse_datestr(date_str, &tm_time); /* Correct any day of week and day of year etc. fields */ - tm_time.tm_isdst = -1; /* Be sure to recheck dst */ + if (check_dst) + tm_time.tm_isdst = -1; /* recheck dst unless date is UTC */ t = validate_tm_time(date_str, &tm_time); timebuf[1].tv_sec = timebuf[0].tv_sec = t; diff --git a/include/libbb.h b/include/libbb.h index 7d6ab4a..1ec8d2d 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -690,7 +690,7 @@ struct BUG_too_small { }; -void parse_datestr(const char *date_str, struct tm *ptm) FAST_FUNC; +int parse_datestr(const char *date_str, struct tm *ptm) FAST_FUNC; time_t validate_tm_time(const char *date_str, struct tm *ptm) FAST_FUNC; char *strftime_HHMMSS(char *buf, unsigned len, time_t *tp) FAST_FUNC; char *strftime_YYYYMMDDHHMMSS(char *buf, unsigned len, time_t *tp) FAST_FUNC; diff --git a/libbb/Config.src b/libbb/Config.src index f97de8e..58c5fad 100644 --- a/libbb/Config.src +++ b/libbb/Config.src @@ -395,3 +395,14 @@ config FEATURE_HWIB default y help Support for printing infiniband addresses in network applets. + +config FEATURE_TIMEZONE + bool "Allow timezone in dates" + default y + depends on DESKTOP + help + Permit the use of timezones when parsing user-provided data + strings, e.g. '1996-04-09 12:45:00 -0500'. + + This requires support for the '%z' extension to strptime() which + may not be available in all implementations. diff --git a/libbb/time.c b/libbb/time.c index 365b1df..41a69c7 100644 --- a/libbb/time.c +++ b/libbb/time.c @@ -8,7 +8,9 @@ */ #include "libbb.h" -void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm) +/* Returns 0 if the time structure contains an absolute UTC time which + * should not be subject to DST adjustment by the caller. */ +int FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm) { char end = '\0'; #if ENABLE_DESKTOP @@ -27,6 +29,10 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm) "%b %d %T %Y" "\0" /* month_name d HH:MM:SS YYYY */ "%Y-%m-%d %R" "\0" /* yyyy-mm-dd HH:MM */ "%Y-%m-%d %T" "\0" /* yyyy-mm-dd HH:MM:SS */ +#if ENABLE_FEATURE_TIMEZONE + "%Y-%m-%d %R %z" "\0" /* yyyy-mm-dd HH:MM TZ */ + "%Y-%m-%d %T %z" "\0" /* yyyy-mm-dd HH:MM:SS TZ */ +#endif "%Y-%m-%d %H" "\0" /* yyyy-mm-dd HH */ "%Y-%m-%d" "\0" /* yyyy-mm-dd */ /* extra NUL */; @@ -38,8 +44,28 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm) fmt = fmt_str; while (*fmt) { endp = strptime(date_str, fmt, ptm); - if (endp && *endp == '\0') - return; + if (endp && *endp == '\0') { +#if ENABLE_FEATURE_TIMEZONE + if (strchr(fmt, 'z')) { + time_t t; + struct tm *utm; + + /* we have timezone offset: obtain Unix time_t */ + ptm->tm_sec -= ptm->tm_gmtoff; + ptm->tm_isdst = 0; + t = timegm(ptm); + if (t == (time_t)-1) + break; + /* convert Unix time_t to struct tm in user's locale */ + utm = localtime(&t); + if (!utm) + break; + *ptm = *utm; + return 0; + } +#endif + return 1; + } *ptm = save; while (*++fmt) continue; @@ -124,7 +150,7 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm) struct tm *lt = localtime(&t); if (lt) { *ptm = *lt; - return; + return 0; } } end = '1'; @@ -241,6 +267,7 @@ void FAST_FUNC parse_datestr(const char *date_str, struct tm *ptm) if (end != '\0') { bb_error_msg_and_die(bb_msg_invalid_date, date_str); } + return 1; } time_t FAST_FUNC validate_tm_time(const char *date_str, struct tm *ptm) diff --git a/testsuite/date/date-timezone b/testsuite/date/date-timezone new file mode 100644 index 0000000..8628aa1 --- /dev/null +++ b/testsuite/date/date-timezone @@ -0,0 +1,32 @@ +# FEATURE: CONFIG_FEATURE_TIMEZONE + +# 'Z' is UTC +dt=$(TZ=UTC0 busybox date -d '1999-1-2 3:4:5Z') +dt=$(echo "$dt" | cut -b1-19) +test x"$dt" = x"Sat Jan 2 03:04:05" + +# '+0600' is six hours ahead of UTC +dt=$(TZ=UTC0 busybox date -d '1999-1-2 3:4:5 +0600') +dt=$(echo "$dt" | cut -b1-19) +test x"$dt" = x"Fri Jan 1 21:04:05" + +# '-0600' is six hours behind UTC +dt=$(TZ=UTC0 busybox date -d '1999-1-2 3:4:5 -0600') +dt=$(echo "$dt" | cut -b1-19) +test x"$dt" = x"Sat Jan 2 09:04:05" + +# before dst is switched on +dt=$(TZ=GMT0BST,M3.5.0/1,M10.5.0/2 busybox date -d '2021-03-28 00:59:59 +0000') +test x"$dt" = x"Sun Mar 28 00:59:59 GMT 2021" + +# after dst is switched on +dt=$(TZ=GMT0BST,M3.5.0/1,M10.5.0/2 busybox date -d '2021-03-28 01:00:01 +0000') +test x"$dt" = x"Sun Mar 28 02:00:01 BST 2021" + +# before dst is switched off +dt=$(TZ=GMT0BST,M3.5.0/1,M10.5.0/2 busybox date -d '2021-10-31 00:00:01 +0000') +test x"$dt" = x"Sun Oct 31 01:00:01 BST 2021" + +# after dst is switched off: back to 01:00:01 but with different TZ +dt=$(TZ=GMT0BST,M3.5.0/1,M10.5.0/2 busybox date -d '2021-10-31 01:00:01 +0000') +test x"$dt" = x"Sun Oct 31 01:00:01 GMT 2021" -- cgit v1.1