Implemented asctime() and asctime_r().

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@7326 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/libroot/posix/time/Jamfile

@@ -1,6 +1,7 @@
 SubDir OBOS_TOP src kernel libroot posix time ;
 
 KernelMergeObject posix_time.o :
+	<$(SOURCE_GRIST)>asctime.c
 	<$(SOURCE_GRIST)>time.c
 	:
 	-fPIC -DPIC

src/kernel/libroot/posix/time/asctime.c

@@ -0,0 +1,49 @@
+/* 
+** Copyright 2004, Axel Dörfler, [email protected]. All rights reserved.
+** Distributed under the terms of the OpenBeOS License.
+*/
+
+
+#include <time.h>
+#include <stdio.h>
+
+
+static char *
+print_time(char *buffer, size_t bufferSize, const struct tm *tm)
+{
+	// ToDo: this should probably use the locale kit to get these names
+
+	static const char weekdays[][3] = {
+		"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
+	};
+	static const char months[][3] = {
+		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+	};
+
+	snprintf(buffer, bufferSize, "%.3s %.3s%3d %02d:%02d:%02d %d\n",
+		weekdays[tm->tm_wday % 7], months[tm->tm_mon % 12],
+		tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec,
+		1900 + tm->tm_year);
+
+	return buffer;
+}
+
+
+char *
+asctime(const struct tm *tm)
+{
+	static char buffer[28];
+		// is enough to hold normal dates
+
+	return print_time(buffer, sizeof(buffer), tm);
+}
+
+
+char *
+asctime_r(const struct tm *tm, char *buffer)
+{
+	return print_time(buffer, 26, tm);
+		// 26 bytes seems to be required by the standard, so we can't write more
+}
+