1 files changed, 67 insertions, 0 deletions
diff --git a/posixtz.c b/posixtz.c
new file mode 100644
index 0000000..cddcb3e
--- /dev/null
+++ b/posixtz.c
@@ -0,0 +1,67 @@
+/* ripped from uclibc 
+*
+* Copyright (C) 2010 Denys Vlasenko <vda.linux@googlemail.com>
+* Copyright (C) 2011 Natanael Copa <ncopa@alpinelinux.org>
+*
+* GNU Library General Public License (LGPL) version 2 or later.
+*
+*/
+
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <err.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+
+#include "posixtz.h"
+
+#ifndef TZNAME_MAX
+#define TZNAME_MAX _POSIX_TZNAME_MAX
+#endif
+
+#define TZ_BUFLEN               (2*TZNAME_MAX + 56)
+
+char *posix_tz(const char *filename)
+{
+	int fd, r;
+	static char buf[TZ_BUFLEN];
+	char *p = NULL;
+	fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		return NULL;
+	
+	r = read(fd, buf, TZ_BUFLEN);
+	if (r != TZ_BUFLEN
+	    || strncmp(buf, "TZif", 4) != 0
+	    || (unsigned char)buf[4] < 2
+	    || lseek(fd, -TZ_BUFLEN, SEEK_END) < 0
+	   )
+		goto ERROR;
+
+	/* tzfile.h from tzcode database says about TZif2+ files:
+	**
+	** If tzh_version is '2' or greater, the above is followed by a second instance
+	** of tzhead and a second instance of the data in which each coded transition
+	** time uses 8 rather than 4 chars,
+	** then a POSIX-TZ-environment-variable-style string for use in handling
+	** instants after the last transition time stored in the file
+	** (with nothing between the newlines if there is no POSIX representation for
+	** such instants).
+	*/
+	r = read(fd, buf, TZ_BUFLEN);
+	if (r <= 0 || buf[--r] != '\n')
+		goto ERROR;
+	buf[r] = 0;
+	while (r != 0) {
+		if (buf[--r] == '\n') {
+			p = buf + r + 1;
+			break;
+		}
+	} /* else ('\n' not found): p remains NULL */
+ERROR:
+	close(fd);
+	return p;
+}
+