Cleanup/refactoring pass on hwclock.

Inline open_wall_clock_rtc() into rtc_open(), factor out xtzset(),
inline set_sysclock_from_hwclock(), set_hwclock_from_sysclock(),
and set_sysclock_timezone().

/etc/adjtime is short enough we don't need to bother with a break.

The final "else" case in main() should always trigger because >0 in optstr
says "at most zero arguments", so the || at the end is always true, so
take the test off.

2 files changed, 12 insertions, 0 deletions

diff --git a/lib/lib.h b/lib/lib.h
index 621ed276..a659b696 100644
--- a/lib/lib.h
+++ b/lib/lib.h
@@ -128,6 +128,7 @@ char *xreadlink(char *name);
 long xparsetime(char *arg, long units, long *fraction);
 void xpidfile(char *name);
 void xregcomp(regex_t *preg, char *rexec, int cflags);
+char *xtzset(char *new);
 
 // lib.c
 void verror_msg(char *msg, int err, va_list va);
diff --git a/lib/xwrap.c b/lib/xwrap.c
index cd3c6845..0a2b38ff 100644
--- a/lib/xwrap.c
+++ b/lib/xwrap.c
@@ -627,3 +627,14 @@ void xregcomp(regex_t *preg, char *regex, int cflags)
     error_exit("xregcomp: %s", libbuf);
   }
 }
+
+char *xtzset(char *new)
+{
+  char *tz = getenv("TZ");
+
+  if (tz) tz = xstrdup(tz);
+  if (setenv("TZ", new, 1)) perror_exit("setenv");
+  tzset();
+
+  return tz;
+}