🚀 go-pugleaf

date -u does not work on some antiquated hosts that don't support setting
the time zone via the TZ environment variable.  One such is the Sequent
Symmetry (Dynix 3.1.2).

>From looking at two other hosts which do support TZ (Ultrix 4.2, SunOS
4.1.2), it would seem that if TZ support is there, so is the function
tzset.  If this is incorrect, another check will have to be substituted.

Here are the unified diffs:

diff -ur tmp/shellutils-1.8/ChangeLog shellutils-1.8/ChangeLog
--- tmp/shellutils-1.8/ChangeLog	Wed Oct 28 12:27:01 1992
+++ shellutils-1.8/ChangeLog	Fri Nov  6 19:29:15 1992
@@ -1,3 +1,17 @@
+Fri Nov  6 19:24:19 1992  Jason Merrill  (jason@jarthur.claremont.edu)
+
+	* Added support in date(1) for hosts that don't support setting the
+	timezone with the environment variable TZ:
+
+	* configure.in: Added check for tzset(3) -- is this always present
+	if the host supports TZ?
+
+	* strftime.c (zone_name): If no tzset, check env manually and
+	return "GMT" if appropriate.
+
+	* date.c (show_date): If no tzset, check env manually and use
+	gmtime(3) if appropriate.
+
 Wed Oct 28 14:16:48 1992  David J. MacKenzie  (djm@goldman.gnu.ai.mit.edu)
 
 	* Version 1.8.
diff -ur tmp/shellutils-1.8/configure.in shellutils-1.8/configure.in
--- tmp/shellutils-1.8/configure.in	Thu Oct  1 17:56:22 1992
+++ shellutils-1.8/configure.in	Fri Nov  6 18:37:59 1992
@@ -82,6 +82,7 @@
 AC_ALLOCA
 AC_STRUCT_TM
 AC_TIMEZONE
+AC_HAVE_FUNCS(tzset)
 AC_XENIX_DIR
 echo checking for libinet
 # Needed on ISC for syslog.
diff -ur tmp/shellutils-1.8/lib/strftime.c shellutils-1.8/lib/strftime.c
--- tmp/shellutils-1.8/lib/strftime.c	Fri Jul 24 14:24:55 1992
+++ shellutils-1.8/lib/strftime.c	Fri Nov  6 19:34:52 1992
@@ -216,6 +216,12 @@
   struct timeval tv;
   struct timezone tz;
 
+#ifndef HAVE_TZSET
+  extern char *getenv();
+  char *tzenv = getenv ("TZ");
+  if (tzenv && *tzenv == '\0')	/* TZ= */
+    return "GMT";
+#endif  
   gettimeofday (&tv, &tz);
   return timezone (tz.tz_minuteswest, tp->tm_isdst);
 }
diff -ur tmp/shellutils-1.8/src/date.c shellutils-1.8/src/date.c
--- tmp/shellutils-1.8/src/date.c	Mon May 11 21:09:07 1992
+++ shellutils-1.8/src/date.c	Fri Nov  6 19:33:28 1992
@@ -156,7 +156,14 @@
   char *out = NULL;
   size_t out_length = 0;
 
-  tm = localtime (&when);
+#ifndef HAVE_TZSET
+  /* Note: the code in strftime.c:zone_name() to determine the time zone
+     requires that TZ_UCT be "TZ=" */
+  if (!strcmp (getenv ("TZ"), TZ_UCT+3))
+    tm = gmtime (&when);
+  else
+#endif /* HAVE_TZSET */
+    tm = localtime (&when);
 
   if (format == NULL)
     /* Print the date in the default format.  Vanilla ANSI C strftime