Re: [parted-devel] [PATCH] [RFC] Do not automatically update GPT label in interactive mode

[Jim Meyering]

Petr Uzel wrote:
> On Wed, Feb 18, 2009 at 08:55:35PM +0100, Jim Meyering wrote:
>> Petr Uzel <address@hidden> wrote:
>> ...
>> >> +test_expect_success \
>> >> +    'save a copy of the original primary GPT table' \
>> >> +    'dd if=$dev of=before count=1 skip=1'
>> >
>> > isn't bs=512 missing here ^^^ ?
>>
>> It's fine to omit it, since bs=512 is the default.
>
> I can confirm that it defaults to 512 on my system. However, I can't
> find any reference about default bs value in the dd documentation
> (more precisely, it is referenced in BSD and HPUX manpages, but not in
> linux).

Thank you for mentioning that.

Here's a proposed patch.
Feedback welcome.
Any language lawyers around? ;-)

>From 0c91ae335d45250ed9024ededd36aac40e071d7b Mon Sep 17 00:00:00 2001
From: Jim Meyering <address@hidden>
Date: Thu, 19 Feb 2009 12:35:58 +0100
Subject: [PATCH] doc: dd: document that the default block size is 512 bytes

* src/dd.c (usage): Document the default block size.
* doc/coreutils.texi (dd invocation): Document that the default
block size (bs, ibs, obs) is 512 bytes.
Reported by Petr Uzel.
---
 THANKS             |    1 +
 doc/coreutils.texi |    2 ++
 src/dd.c           |    6 +++---
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/THANKS b/THANKS
index bedb01a..f2fcd01 100644
--- a/THANKS
+++ b/THANKS
@@ -446,6 +446,7 @@ Peter Moulder                       address@hidden
 Peter O'Gorman                      address@hidden
 Peter Samuelson                     address@hidden
 Peter Seebach                       address@hidden
+Petr Uzel                           address@hidden
 Petter Reinholdtsen                 address@hidden
 Phelippe Neveu                      address@hidden
 Phil Richards                       address@hidden
diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index 42234d3..8d496ad 100644
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -7605,6 +7605,7 @@ dd invocation
 @cindex input block size
 Set the input block size to @var{bytes}.
 This makes @command{dd} read @var{bytes} per block.
+The default is 512 bytes.

 @item address@hidden
 @opindex obs
@@ -7612,6 +7613,7 @@ dd invocation
 @cindex output block size
 Set the output block size to @var{bytes}.
 This makes @command{dd} write @var{bytes} per block.
+The default is 512 bytes.

 @item address@hidden
 @opindex bs
diff --git a/src/dd.c b/src/dd.c
index 4604ced..6837b7b 100644
--- a/src/dd.c
+++ b/src/dd.c
@@ -463,16 +463,16 @@ Usage: %s [OPERAND]...\n\
       fputs (_("\
 Copy a file, converting and formatting according to the operands.\n\
 \n\
-  bs=BYTES        read and write BYTES bytes at a time\n\
+  bs=BYTES        read and write BYTES bytes at a time (also see ibs=,obs=)\n\
   cbs=BYTES       convert BYTES bytes at a time\n\
   conv=CONVS      convert the file as per the comma separated symbol list\n\
   count=BLOCKS    copy only BLOCKS input blocks\n\
-  ibs=BYTES       read BYTES bytes at a time\n\
+  ibs=BYTES       read BYTES bytes at a time (default: 512)\n\
 "), stdout);
       fputs (_("\
   if=FILE         read from FILE instead of stdin\n\
   iflag=FLAGS     read as per the comma separated symbol list\n\
-  obs=BYTES       write BYTES bytes at a time\n\
+  obs=BYTES       write BYTES bytes at a time (default: 512)\n\
   of=FILE         write to FILE instead of stdout\n\
   oflag=FLAGS     write as per the comma separated symbol list\n\
   seek=BLOCKS     skip BLOCKS obs-sized blocks at start of output\n\
--
1.6.2.rc1.241.g7bf82