[PATCH] doc: mention the '0#' printf flags with stat %a

[Pádraig Brady]

* src/stat.c (usage): Mention the '#' and '0' flags are useful with %a.
* doc/coreutils.texi (stat invocation): Likewise.  Also give an example
printing unambiguous octal output.
Reported at http://bugs.debian.org/810539
---
 doc/coreutils.texi | 7 ++++++-
 src/stat.c         | 2 +-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 2538062..6f86b28 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -11721,7 +11721,7 @@ The valid @var{format} directives for files with 
@option{--format} and
 @option{--printf} are:
 
 @itemize @bullet
-@item %a - Access rights in octal
+@item %a - Access rights in octal (note @samp{#} and @samp{0} printf flags)
 @item %A - Access rights in human readable form
 @item %b - Number of blocks allocated (see @samp{%B})
 @item %B - The size in bytes of each block reported by @samp{%b}
@@ -11753,6 +11753,11 @@ The valid @var{format} directives for files with 
@option{--format} and
 @item %Z - Time of last status change as seconds since Epoch
 @end itemize
 
+The @samp{%a} format prints the octal mode, and so it is useful
+to control the zero padding of the output with the @samp{#} and @samp{0}
+printf flags. For example to pad to at least 3 wide while making larger
+numbers unambiguously octal, you can use @samp{%#03a}.
+
 The @samp{%t} and @samp{%T} formats operate on the st_rdev member of
 the stat(2) structure, and are only defined for character and block
 special files.  On some systems or file types, st_rdev may be used to
diff --git a/src/stat.c b/src/stat.c
index 3c69264..e11e431 100644
--- a/src/stat.c
+++ b/src/stat.c
@@ -1453,7 +1453,7 @@ Display file or file system status.\n\
       fputs (_("\n\
 The valid format sequences for files (without --file-system):\n\
 \n\
-  %a   access rights in octal\n\
+  %a   access rights in octal (note '#' and '0' printf flags)\n\
   %A   access rights in human readable form\n\
   %b   number of blocks allocated (see %B)\n\
   %B   the size in bytes of each block reported by %b\n\
-- 
2.5.0