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authorDenys Vlasenko <vda.linux@googlemail.com>2020-12-16 20:55:30 +0100
committerDenys Vlasenko <vda.linux@googlemail.com>2020-12-16 20:55:30 +0100
commitd3c36882dc5bc5fcede9a45a6bc7a39570fba7d0 (patch)
tree4c9bb1c2b84baf964ecec6dbcd2b50067d98e19f
parent9e262f13c2e53490d69d3112ffd718c27de04d1f (diff)
downloadbusybox-d3c36882dc5bc5fcede9a45a6bc7a39570fba7d0.tar.gz
hwclock: improve --help (-l is a compatible shortcut for --localtime)
function old new delta packed_usage 33605 33568 -37 Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--util-linux/hwclock.c69
1 files changed, 50 insertions, 19 deletions
diff --git a/util-linux/hwclock.c b/util-linux/hwclock.c
index 44cb4794e..77aa2d7c3 100644
--- a/util-linux/hwclock.c
+++ b/util-linux/hwclock.c
@@ -153,14 +153,12 @@ static void set_kernel_tz(const struct timezone *tz)
* then system time is wrong - it is offset by timezone.
* --systz option corrects system time if RTC is in local time,
* and (always) sets in-kernel timezone.
- *
- * This is an alternate option to --hctosys that does not read the
- * hardware clock.
+ * (Unlike --hctosys, it does not read the RTC).
*
* util-linux's code has this comment:
* RTC | settimeofday calls
* ------|-------------------------------------------------
- * Local | 1) warps system time*, sets PCIL* and kernel tz
+ * Local | 1st) warps system time*, sets PCIL* and kernel tz
* UTC | 1st) locks warp_clock 2nd) sets kernel tz
* * only on first call after boot
* (PCIL is "persistent_clock_is_local" kernel internal flag,
@@ -177,6 +175,9 @@ static void set_kernel_timezone_and_clock(int utc, const struct timeval *hctosys
set_kernel_tz(&tz);
/* Set kernel's timezone offset based on userspace one */
+//It's tempting to call tzset() and use libc global "timezone" variable
+//...but it does NOT include DST shift (IOW: it's WRONG, usually by one hour,
+//if DST is in effect!) Thus this ridiculous dance:
cur = time(NULL);
broken = localtime(&cur);
tz.tz_minuteswest = -broken->tm_gmtoff / 60;
@@ -321,30 +322,58 @@ static void from_sys_clock(const char **pp_rtcname, int utc)
close(rtc);
}
+// hwclock from util-linux 2.36.1
+// hwclock [function] [option...]
+//Functions:
+// -r, --show display the RTC time
+// --get display drift corrected RTC time
+// --set set the RTC according to --date
+// -s, --hctosys set the system time from the RTC
+// -w, --systohc set the RTC from the system time
+// --systz send timescale configurations to the kernel
+// -a, --adjust adjust the RTC to account for systematic drift
+// --predict predict the drifted RTC time according to --date
+//Options:
+// -u, --utc the RTC timescale is UTC
+// -l, --localtime the RTC timescale is Local
+// -f, --rtc <file> use an alternate file to /dev/rtc0
+// --directisa use the ISA bus instead of /dev/rtc0 access
+// --date <time> date/time input for --set and --predict
+// --delay <sec> delay used when set new RTC time
+// --update-drift update the RTC drift factor
+// --noadjfile do not use /etc/adjtime
+// --adjfile <file> use an alternate file to /etc/adjtime
+// --test dry run; implies --verbose
+// -v, --verbose display more details
+
+//usage:#if ENABLE_FEATURE_HWCLOCK_ADJTIME_FHS
+//usage:# define ADJTIME_PATH "/var/lib/hwclock/adjtime"
+//usage:#else
+//usage:# define ADJTIME_PATH "/etc/adjtime"
+//usage:#endif
//usage:#define hwclock_trivial_usage
//usage: IF_LONG_OPTS(
-//usage: "[-swu] [--systz] [--localtime] [-f FILE]"
+//usage: "[-swul] [--systz] [-f DEV]"
//usage: )
//usage: IF_NOT_LONG_OPTS(
-//usage: "[-swtlu] [-f FILE]"
+//usage: "[-swult] [-f DEV]"
//usage: )
//usage:#define hwclock_full_usage "\n\n"
//usage: "Show or set hardware clock (RTC)\n"
-///////: "\n -r Show hardware clock time"
+///////: "\n -r Show RTC time"
///////-r is default, don't bother showing it in help
-//usage: "\n -s Set system time from hardware clock"
-//usage: "\n -w Set hardware clock from system time"
+//usage: "\n -s Set system time from RTC"
+//usage: "\n -w Set RTC from system time"
//usage: IF_LONG_OPTS(
//usage: "\n --systz Set in-kernel timezone, correct system time"
+//usage: "\n if RTC is kept in local time"
//usage: )
-//usage: "\n if hardware clock is in local time"
-//usage: "\n -u Assume hardware clock is kept in UTC"
-//usage: IF_LONG_OPTS(
-//usage: "\n --localtime Assume hardware clock is kept in local time"
-//usage: )
-//usage: "\n -f FILE Use specified device (e.g. /dev/rtc2)"
+//usage: "\n -f DEV Use specified device (e.g. /dev/rtc2)"
+//usage: "\n -u Assume RTC is kept in UTC"
+//usage: "\n -l Assume RTC is kept in local time"
+//usage: "\n (if neither is given, read from "ADJTIME_PATH")"
-//TODO: get rid of incompatible -t and -l aliases to --systz and --localtime
+//TODO: get rid of incompatible -t alias to --systz?
#define HWCLOCK_OPT_LOCALTIME 0x01
#define HWCLOCK_OPT_UTC 0x02
@@ -362,7 +391,7 @@ int hwclock_main(int argc UNUSED_PARAM, char **argv)
int utc;
#if ENABLE_LONG_OPTS
static const char hwclock_longopts[] ALIGN1 =
- "localtime\0" No_argument "l" /* short opt is non-standard */
+ "localtime\0" No_argument "l"
"utc\0" No_argument "u"
"show\0" No_argument "r"
"hctosys\0" No_argument "s"
@@ -372,12 +401,14 @@ int hwclock_main(int argc UNUSED_PARAM, char **argv)
;
#endif
opt = getopt32long(argv,
- "^lurswtf:" "\0" "r--wst:w--rst:s--wrt:t--rsw:l--u:u--l",
+ "^""lurswtf:v" /* -v is accepted and ignored */
+ "\0"
+ "r--wst:w--rst:s--wrt:t--rsw:l--u:u--l",
hwclock_longopts,
&rtcname
);
- /* If -u or -l wasn't given check if we are using utc */
+ /* If -u or -l wasn't given, check if we are using utc */
if (opt & (HWCLOCK_OPT_UTC | HWCLOCK_OPT_LOCALTIME))
utc = (opt & HWCLOCK_OPT_UTC);
else