Re: [coreutils] [PATCH 1/2] stat: support printing birthtime

[Eric Blake]

On 10/01/2010 03:18 AM, Jim Meyering wrote:
> As Pádraig mentioned, s/%x/%w/ and s/%X/%W/

Fixed.

> Regarding whether to print " Birth: -" in the default output when
> no information is available, I have a slight preference to print it.
> First, it should be fine, since no one should be parsing that default
> output, so we can change it without fear of breaking client scripts.
> Second, seeing that empty line there may encourage users and developers
> of lagging file systems and/or kernels to add support (yeah, right).

OK, I'm keeping it in.

Here's the test I'm squashing in (plus a cleanup in patch 2/2, when %X 
is taught sub-second resolution).

diff --git c/doc/coreutils.texi i/doc/coreutils.texi
index c5dda4f..12f103a 100644
--- c/doc/coreutils.texi
+++ i/doc/coreutils.texi
@@ -10697,7 +10697,7 @@ stat invocation
 @item %u - User ID of owner
 @item %U - User name of owner
 @item %w - Time of file birth, or @samp{-} if unknown
-@item %W - Time of last birth as seconds since Epoch, or @samp{-}
+@item %W - Time of file birth as seconds since Epoch, or @samp{-}
 @item %x - Time of last access
 @item %X - Time of last access as seconds since Epoch
 @item %y - Time of last modification
diff --git c/src/stat.c i/src/stat.c
index c465e77..2b4a048 100644
--- c/src/stat.c
+++ i/src/stat.c
@@ -1150,8 +1150,8 @@ The valid format sequences for files (without 
--file-system):\n\
       fputs (_("\
   %u   User ID of owner\n\
   %U   User name of owner\n\
-  %x   Time of file birth, or - if unknown\n\
-  %X   Time of file birth as seconds since Epoch, or - if unknown\n\
+  %w   Time of file birth, or - if unknown\n\
+  %W   Time of file birth as seconds since Epoch, or - if unknown\n\
   %x   Time of last access\n\
   %X   Time of last access as seconds since Epoch\n\
   %y   Time of last modification\n\
diff --git c/tests/Makefile.am i/tests/Makefile.am
index 3236637..a6a0594 100644
--- c/tests/Makefile.am
+++ i/tests/Makefile.am
@@ -239,6 +239,7 @@ TESTS =                                             \
   misc/split-a                                 \
   misc/split-fail                              \
   misc/split-l                                 \
+  misc/stat-birthtime                          \
   misc/stat-fmt                                        \
   misc/stat-hyphen                             \
   misc/stat-mount                              \
diff --git c/tests/misc/stat-birthtime i/tests/misc/stat-birthtime
new file mode 100755
index 0000000..d4f372e
--- /dev/null
+++ i/tests/misc/stat-birthtime
@@ -0,0 +1,46 @@
+#!/bin/sh
+# ensure that stat attempts birthtime access
+
+# Copyright (C) 2010 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
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+if test "$VERBOSE" = yes; then
+  set -x
+  stat --version
+fi
+
+. $srcdir/test-lib.sh
+
+# Whether birthtime is supported or not, it better not change even when
+# [acm]time are modified.  :)
+touch a || fail=1
+btime=$(stat --format %W a) || fail=1
+atime=$(stat --format %X a) || fail=1
+mtime=$(stat --format %Y a) || fail=1
+ctime=$(stat --format %Z a) || fail=1
+
+case $(stat --format %x a) in
+  *.000000000*) sleep 2;; # worst case file system is FAT
+  *) # FIXME: sleep .1 would be sufficient if %X showed nanoseconds
+ sleep 1;; # should be adequate for any system with subsecond resolution
+esac
+
+touch a || fail=1
+test "x$btime" = x$(stat --format %W a) || fail=1
+test "x$atime" != x$(stat --format %X a) || fail=1
+test "x$mtime" != x$(stat --format %Y a) || fail=1
+test "x$ctime" != x$(stat --format %Z a) || fail=1
+
+Exit $fail


--
Eric Blake   address@hidden    +1-801-349-2682
Libvirt virtualization library http://libvirt.org