Initial revision

lang/cem/libcc/stdio/timezone.c

@@ -0,0 +1,59 @@
+static struct zonetable {
+	int	offset;
+	char	*stdzone;
+	char	*dstzone;
+} zonetable[] = {
+	-3*60-30, "NST", 0,	/* new foundland ??? */
+	-4*60, "AST", "ADT",	/* atlanic */
+	-5*60, "EST", "EDT",	/* eastern */
+	-6*60, "CST", "CDT",	/* central */
+	-7*60, "MST", "MDT",	/* mountain */
+	-8*60, "PST", "PDT",	/* pacific */
+	-9*60, "YST", "YDT",	/* yukon */
+	-10*60, "AST", "ADT",	/* aleutian */
+	-10*60, "HST", "HDT",	/* hawai, never found */
+	0, "GMT", 0,		/* Greenwich */
+	0, "WET", "WDT",	/* west european, never found */
+	1*60,"MET", "MDT",	/* middle european */
+	2*60, "EET", "EDT",	/* east european */
+	8*60, "WST", 0,	/* west australia */
+	9*60, "JST", 0,	/* japan */
+	9*60+30, "CST", 0,	/* also australia ??? */
+	10*60, "EST", 0,	/* also australia ??? */
+	-1			
+};
+
+char *
+timezone(zone, dst)
+{
+	register struct zonetable *p = zonetable;
+	static char buf[16];
+	register char *c;
+	int i;
+
+	while (p->offset != -1) {
+		if (zone == -p->offset) {
+			if (dst && p->dstzone) return p->dstzone;
+			if (!dst && p->stdzone) return p->stdzone;
+		}
+		p++;
+	}
+	*c++ = 'G';
+	*c++ = 'M';
+	*c++ = 'T';
+	if (zone < 0) {
+		zone = - zone;
+		*c++ = '+';
+	}
+	else	*c++ = '-';
+	i = (zone / 60) % 24;
+	if (i >= 10) {
+		*c++ = i / 10 + '0';
+	}
+	*c++ = i % 10 + '0';
+	i = zone % 60;
+	*c++ = i / 10 + '0';
+	*c++ = i % 10 + '0';
+	*c = '\0';
+	return buf;
+}