I recently redisovered the fact that actime_r and ctime_r, like
asctime and ctime, are unsafe functions in the same sense that gets is
unsafe: they can overrun their output buffers and there's no simple
way for the user to detect in advance whether this will happen. So
GNU apps shouldn't use these functions, and I propose that we remove
these function emulations from gnulib, as follows. Any objections?
--- ../gnulib/lib/time_r.h 2005-07-11 04:21:55.000000000 -0700
+++ lib/time_r.h 2006-03-10 01:39:10.000000000 -0800
@@ -1,6 +1,6 @@
/* Reentrant time functions like localtime_r.
- Copyright (C) 2003, 2005 Free Software Foundation, Inc.
+ Copyright (C) 2003, 2005, 2006 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -27,25 +27,20 @@
#include <time.h>
#if !HAVE_TIME_R_POSIX
-# undef asctime_r
-# undef ctime_r
+
+/* Don't bother with asctime_r and ctime_r, since these functions are
+ not safe (like asctime and ctime, they can overrun their 26-byte
+ output buffers when given outlandish struct tm values), and we
+ don't want to encourage applications to use unsafe functions. Use
+ strftime or even sprintf instead. */
+
# undef gmtime_r
# undef localtime_r
-# define asctime_r rpl_asctime_r
-# define ctime_r rpl_ctime_r
# define gmtime_r rpl_gmtime_r
# define localtime_r rpl_localtime_r
/* See the POSIX:2001 specification
- <http://www.opengroup.org/susv3xsh/asctime.html>. */
-char *asctime_r (struct tm const * restrict, char * restrict);
-
-/* See the POSIX:2001 specification
- <http://www.opengroup.org/susv3xsh/ctime.html>. */
-char *ctime_r (time_t const *, char *);
-
-/* See the POSIX:2001 specification
<http://www.opengroup.org/susv3xsh/gmtime.html>. */
struct tm *gmtime_r (time_t const * restrict, struct tm * restrict);
--- ../gnulib/lib/time_r.c 2005-09-19 10:28:15.000000000 -0700
+++ lib/time_r.c 2006-03-10 01:34:06.000000000 -0800
@@ -44,18 +44,6 @@ copy_tm_result (struct tm *dest, struct
}
-char *
-asctime_r (struct tm const * restrict tm, char * restrict buf)
-{
- return copy_string_result (buf, asctime (tm));
-}
-
-char *
-ctime_r (time_t const *t, char *buf)
-{
- return copy_string_result (buf, ctime (t));
-}
-
struct tm *
gmtime_r (time_t const * restrict t, struct tm * restrict tp)
{
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