piping output of dd through bzip2

piping output of dd through bzip2

[Gregory Nowak]

Hi all,

I'm trying to image a partition with dd, and pass the output to bzip2. However, bzip2 tells me that input file file.img cannot be found. Can someone tell me the correct cyntax please?
I'm doing the following: "dd if=/dev/hda1 |bzip2 -9 file.img"
Thanks in advance for any help.
Greg

Re: piping output of dd through bzip2

[Steve Holmes]

The output of dd always goes to the device or file specified for of=
Example: dd if=/dev/hda of=something
My problem here is I don't know how you can specify that of is to be piped
into bzip2.  Some programs use the `-' to represent the standard pipe. in
which case, you might be able to say:
dd if=/dev/hda of=-; bzipz -
Sorry, don't have experience with bzip2's command parms but hopefully this
makes sense in concept.

On Sun, 13 Jan 2002, Gregory Nowak wrote:

> Hi all,
>
> I'm trying to image a partition with dd, and pass the output to bzip2. However, bzip2 tells me that input file file.img cannot be found. Can someone tell me the correct cyntax please?
> I'm doing the following: "dd if=/dev/hda1 |bzip2 -9 file.img"
> Thanks in advance for any help.
> Greg
>
>
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
>

Re: piping output of dd through bzip2

[Jason]

no need to even do that, dd's output only goes to 'of' if the of= parameter 
is specified, otehrwise it copies to standard output.

all you would need is:
dd if=/dev/hda | bzip <whatever>
replace <whatever> with the command line parameters needed for bzip to output 
to a file (refer to 'man bzip' for details).

> The output of dd always goes to the device or file specified for of=
> Example: dd if=/dev/hda of=something
> My problem here is I don't know how you can specify that of is to be piped
> into bzip2.  Some programs use the `-' to represent the standard pipe. in
> which case, you might be able to say:
> dd if=/dev/hda of=-; bzipz -
> Sorry, don't have experience with bzip2's command parms but hopefully this
> makes sense in concept.

Re: piping output of dd through bzip2

[Gregory Nowak]

Ok, I've just tried the following using the format indicated.

"dd if=/dev/hda1 |bzip2 -9 windows.img"

The result was:

bzip2: Can't open input file windows.img: No such file or directory.
9+0 records in
8+0 records out


Greg


On Mon, Jan 14, 2002 at 03:25:30PM -0700, Jason wrote:
> no need to even do that, dd's output only goes to 'of' if the of= parameter 
> is specified, otehrwise it copies to standard output.
> 
> all you would need is:
> dd if=/dev/hda | bzip <whatever>
> replace <whatever> with the command line parameters needed for bzip to output 
> to a file (refer to 'man bzip' for details).
> 
> > The output of dd always goes to the device or file specified for of=
> > Example: dd if=/dev/hda of=something
> > My problem here is I don't know how you can specify that of is to be piped
> > into bzip2.  Some programs use the `-' to represent the standard pipe. in
> > which case, you might be able to say:
> > dd if=/dev/hda of=-; bzipz -
> > Sorry, don't have experience with bzip2's command parms but hopefully this
> > makes sense in concept.
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup

Re: piping output of dd through bzip2

[Jason]

try it with 'bzip > windows.img'
On Monday January 14, 2002 03:42 pm, you wrote:
> Ok, I've just tried the following using the format indicated.
>
> "dd if=/dev/hda1 |bzip2 -9 windows.img"
>
> The result was:
>
> bzip2: Can't open input file windows.img: No such file or directory.
> 9+0 records in
> 8+0 records out
>
>
> Greg
>

Re: piping output of dd through bzip2

[Gregory Nowak]

Why should I use bzip if bzip2 gives better compression?
Greg


On Mon, Jan 14, 2002 at 03:57:06PM -0700, Jason wrote:
> try it with 'bzip > windows.img'
> On Monday January 14, 2002 03:42 pm, you wrote:
> > Ok, I've just tried the following using the format indicated.
> >
> > "dd if=/dev/hda1 |bzip2 -9 windows.img"
> >
> > The result was:
> >
> > bzip2: Can't open input file windows.img: No such file or directory.
> > 9+0 records in
> > 8+0 records out
> >
> >
> > Greg
> >
> 
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup

Re: piping output of dd through bzip2

[Jason]

ok, ok, gzip, bzip, bzip2, <insert your standard input to standard output 
compressor here>, whatever, they'll all work

On Monday January 14, 2002 05:46 pm, you wrote:
> Why should I use bzip if bzip2 gives better compression?
> Greg
>
> On Mon, Jan 14, 2002 at 03:57:06PM -0700, Jason wrote:
> > try it with 'bzip > windows.img'
> >
> > On Monday January 14, 2002 03:42 pm, you wrote:
> > > Ok, I've just tried the following using the format indicated.
> > >
> > > "dd if=/dev/hda1 |bzip2 -9 windows.img"
> > >
> > > The result was:
> > >
> > > bzip2: Can't open input file windows.img: No such file or directory.
> > > 9+0 records in
> > > 8+0 records out
> > >
> > >
> > > Greg
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
>
> _______________________________________________
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> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup

Re: piping output of dd through bzip2

[Gregory Nowak]

Well, bzip2 doesn't seem to work because it gave me that error.
Greg


On Mon, Jan 14, 2002 at 05:58:43PM -0700, Jason wrote:
> ok, ok, gzip, bzip, bzip2, <insert your standard input to standard output 
> compressor here>, whatever, they'll all work
> 
> On Monday January 14, 2002 05:46 pm, you wrote:
> > Why should I use bzip if bzip2 gives better compression?
> > Greg
> >
> > On Mon, Jan 14, 2002 at 03:57:06PM -0700, Jason wrote:
> > > try it with 'bzip > windows.img'
> > >
> > > On Monday January 14, 2002 03:42 pm, you wrote:
> > > > Ok, I've just tried the following using the format indicated.
> > > >
> > > > "dd if=/dev/hda1 |bzip2 -9 windows.img"
> > > >
> > > > The result was:
> > > >
> > > > bzip2: Can't open input file windows.img: No such file or directory.
> > > > 9+0 records in
> > > > 8+0 records out
> > > >
> > > >
> > > > Greg
> > >
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 
> _______________________________________________
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Re: piping output of dd through bzip2

[Jason]

did you try it with output the redirection symbol(">" [greater than sign])?
On Monday January 14, 2002 06:07 pm, you wrote:
> Well, bzip2 doesn't seem to work because it gave me that error.
> Greg
>
> On Mon, Jan 14, 2002 at 05:58:43PM -0700, Jason wrote:
> > ok, ok, gzip, bzip, bzip2, <insert your standard input to standard output
> > compressor here>, whatever, they'll all work
> >
> > On Monday January 14, 2002 05:46 pm, you wrote:
> > > Why should I use bzip if bzip2 gives better compression?
> > > Greg
> > >
> > > On Mon, Jan 14, 2002 at 03:57:06PM -0700, Jason wrote:
> > > > try it with 'bzip > windows.img'
> > > >
> > > > On Monday January 14, 2002 03:42 pm, you wrote:
> > > > > Ok, I've just tried the following using the format indicated.
> > > > >
> > > > > "dd if=/dev/hda1 |bzip2 -9 windows.img"
> > > > >
> > > > > The result was:
> > > > >
> > > > > bzip2: Can't open input file windows.img: No such file or
> > > > > directory. 9+0 records in
> > > > > 8+0 records out
> > > > >
> > > > >
> > > > > Greg
> > > >
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup@braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > >
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
>
> _______________________________________________
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Re: piping output of dd through bzip2

[Gregory Nowak]

Sure did, got an error too. If you want to see it, I'll run the commands and post it. It was an error from dd stating that bzip2 could not be crated, and that '-9' is an invalid dd option.
Greg


On Mon, Jan 14, 2002 at 06:19:54PM -0700, Jason wrote:
> did you try it with output the redirection symbol(">" [greater than sign])?
> On Monday January 14, 2002 06:07 pm, you wrote:
> > Well, bzip2 doesn't seem to work because it gave me that error.
> > Greg
> >
> > On Mon, Jan 14, 2002 at 05:58:43PM -0700, Jason wrote:
> > > ok, ok, gzip, bzip, bzip2, <insert your standard input to standard output
> > > compressor here>, whatever, they'll all work
> > >
> > > On Monday January 14, 2002 05:46 pm, you wrote:
> > > > Why should I use bzip if bzip2 gives better compression?
> > > > Greg
> > > >
> > > > On Mon, Jan 14, 2002 at 03:57:06PM -0700, Jason wrote:
> > > > > try it with 'bzip > windows.img'
> > > > >
> > > > > On Monday January 14, 2002 03:42 pm, you wrote:
> > > > > > Ok, I've just tried the following using the format indicated.
> > > > > >
> > > > > > "dd if=/dev/hda1 |bzip2 -9 windows.img"
> > > > > >
> > > > > > The result was:
> > > > > >
> > > > > > bzip2: Can't open input file windows.img: No such file or
> > > > > > directory. 9+0 records in
> > > > > > 8+0 records out
> > > > > >
> > > > > >
> > > > > > Greg
> > > > >
> > > > > _______________________________________________
> > > > > Speakup mailing list
> > > > > Speakup@braille.uwo.ca
> > > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > >
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup@braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > >
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> 
> _______________________________________________
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Re: piping output of dd through bzip2

[Steve Holmes]

I just did and got it to work here.

dd if=/dev/hda1 bs=1024 count=1024 |bzip >windows.img

I noticed that dd of a 3.5 gig partition was gonna take a very long time.
The output of my little test confirmed equal in and out counts but there
was no output messages from bzip2; I suppose that's normal behavior for
that program.  The bzip2 man page mentions a -c option for standard input
and output but not sure when that is actually needed.  Perhaps so if a
filename is specified but you want the output to go to stdout.  I did my
tests without the option.

On Mon, 14 Jan 2002, Jason wrote:

> did you try it with output the redirection symbol(">" [greater than sign])?
> On Monday January 14, 2002 06:07 pm, you wrote:
> > Well, bzip2 doesn't seem to work because it gave me that error.
> > Greg
> >
> > On Mon, Jan 14, 2002 at 05:58:43PM -0700, Jason wrote:
> > > ok, ok, gzip, bzip, bzip2, <insert your standard input to standard output
> > > compressor here>, whatever, they'll all work
> > >
> > > On Monday January 14, 2002 05:46 pm, you wrote:
> > > > Why should I use bzip if bzip2 gives better compression?
> > > > Greg
> > > >
> > > > On Mon, Jan 14, 2002 at 03:57:06PM -0700, Jason wrote:
> > > > > try it with 'bzip > windows.img'
> > > > >
> > > > > On Monday January 14, 2002 03:42 pm, you wrote:
> > > > > > Ok, I've just tried the following using the format indicated.
> > > > > >
> > > > > > "dd if=/dev/hda1 |bzip2 -9 windows.img"
> > > > > >
> > > > > > The result was:
> > > > > >
> > > > > > bzip2: Can't open input file windows.img: No such file or
> > > > > > directory. 9+0 records in
> > > > > > 8+0 records out
> > > > > >
> > > > > >
> > > > > > Greg
> > > > >
> > > > > _______________________________________________
> > > > > Speakup mailing list
> > > > > Speakup@braille.uwo.ca
> > > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > >
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup@braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > >
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
>
> _______________________________________________
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Re: piping output of dd through bzip2

[Kirk Wood]

On Mon, 14 Jan 2002, Gregory Nowak wrote:
> Well, bzip2 doesn't seem to work because it gave me that error.

I think it is all in the syntax. Alternatively you could hit the "you know
what I mean" key and try it again. <joke>

=======
Kirk Wood
Cpt.Kirk@1tree.net

Nowlan's Theory:
        He who hesitates is not only lost, but several miles from
        the next freeway exit.

Re: piping output of dd through bzip2

[Steve Holmes]

<hmmm> wonder if that's when one needs to use the -c option? Haven't done
a lot with gzip nor bzip when it comes to unusual practices like pipes and
the like.  The man page says that if no arguments are specified that bzip2
will read from stdin and write to stdout.  Tylor's and my tests indicated
that success but the -9 might have thrown the thing off.  So if -c is
added, that might work.

Well, I did my same test again but added the -9 option and got same
results as before - no errors.

On Mon, 14 Jan 2002, Gregory Nowak wrote:

> Sure did, got an error too. If you want to see it, I'll run the commands and post it. It was an error from dd stating that bzip2 could not be crated, and that '-9' is an invalid dd option.
> Greg
>
>
> On Mon, Jan 14, 2002 at 06:19:54PM -0700, Jason wrote:
> > did you try it with output the redirection symbol(">" [greater than sign])?
> > On Monday January 14, 2002 06:07 pm, you wrote:
> > > Well, bzip2 doesn't seem to work because it gave me that error.
> > > Greg
> > >
> > > On Mon, Jan 14, 2002 at 05:58:43PM -0700, Jason wrote:
> > > > ok, ok, gzip, bzip, bzip2, <insert your standard input to standard output
> > > > compressor here>, whatever, they'll all work
> > > >
> > > > On Monday January 14, 2002 05:46 pm, you wrote:
> > > > > Why should I use bzip if bzip2 gives better compression?
> > > > > Greg
> > > > >
> > > > > On Mon, Jan 14, 2002 at 03:57:06PM -0700, Jason wrote:
> > > > > > try it with 'bzip > windows.img'
> > > > > >
> > > > > > On Monday January 14, 2002 03:42 pm, you wrote:
> > > > > > > Ok, I've just tried the following using the format indicated.
> > > > > > >
> > > > > > > "dd if=/dev/hda1 |bzip2 -9 windows.img"
> > > > > > >
> > > > > > > The result was:
> > > > > > >
> > > > > > > bzip2: Can't open input file windows.img: No such file or
> > > > > > > directory. 9+0 records in
> > > > > > > 8+0 records out
> > > > > > >
> > > > > > >
> > > > > > > Greg
> > > > > >
> > > > > > _______________________________________________
> > > > > > Speakup mailing list
> > > > > > Speakup@braille.uwo.ca
> > > > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > > >
> > > > > _______________________________________________
> > > > > Speakup mailing list
> > > > > Speakup@braille.uwo.ca
> > > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > >
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup@braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > >
> > > _______________________________________________
> > > Speakup mailing list
> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
>
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Re: piping output of dd through bzip2

[Gregory Nowak]

When I tried Tylor's suggestion which worked, I put the '-9' as the last option, and neither program complained.
Greg


On Mon, Jan 14, 2002 at 07:28:38PM -0700, Steve Holmes wrote:
> <hmmm> wonder if that's when one needs to use the -c option? Haven't done
> a lot with gzip nor bzip when it comes to unusual practices like pipes and
> the like.  The man page says that if no arguments are specified that bzip2
> will read from stdin and write to stdout.  Tylor's and my tests indicated
> that success but the -9 might have thrown the thing off.  So if -c is
> added, that might work.
> 
> Well, I did my same test again but added the -9 option and got same
> results as before - no errors.
> 
> On Mon, 14 Jan 2002, Gregory Nowak wrote:
> 
> > Sure did, got an error too. If you want to see it, I'll run the commands and post it. It was an error from dd stating that bzip2 could not be crated, and that '-9' is an invalid dd option.
> > Greg
> >
> >
> > On Mon, Jan 14, 2002 at 06:19:54PM -0700, Jason wrote:
> > > did you try it with output the redirection symbol(">" [greater than sign])?
> > > On Monday January 14, 2002 06:07 pm, you wrote:
> > > > Well, bzip2 doesn't seem to work because it gave me that error.
> > > > Greg
> > > >
> > > > On Mon, Jan 14, 2002 at 05:58:43PM -0700, Jason wrote:
> > > > > ok, ok, gzip, bzip, bzip2, <insert your standard input to standard output
> > > > > compressor here>, whatever, they'll all work
> > > > >
> > > > > On Monday January 14, 2002 05:46 pm, you wrote:
> > > > > > Why should I use bzip if bzip2 gives better compression?
> > > > > > Greg
> > > > > >
> > > > > > On Mon, Jan 14, 2002 at 03:57:06PM -0700, Jason wrote:
> > > > > > > try it with 'bzip > windows.img'
> > > > > > >
> > > > > > > On Monday January 14, 2002 03:42 pm, you wrote:
> > > > > > > > Ok, I've just tried the following using the format indicated.
> > > > > > > >
> > > > > > > > "dd if=/dev/hda1 |bzip2 -9 windows.img"
> > > > > > > >
> > > > > > > > The result was:
> > > > > > > >
> > > > > > > > bzip2: Can't open input file windows.img: No such file or
> > > > > > > > directory. 9+0 records in
> > > > > > > > 8+0 records out
> > > > > > > >
> > > > > > > >
> > > > > > > > Greg
> > > > > > >
> > > > > > > _______________________________________________
> > > > > > > Speakup mailing list
> > > > > > > Speakup@braille.uwo.ca
> > > > > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > > > >
> > > > > > _______________________________________________
> > > > > > Speakup mailing list
> > > > > > Speakup@braille.uwo.ca
> > > > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > > >
> > > > > _______________________________________________
> > > > > Speakup mailing list
> > > > > Speakup@braille.uwo.ca
> > > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > > >
> > > > _______________________________________________
> > > > Speakup mailing list
> > > > Speakup@braille.uwo.ca
> > > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> > >
> > > _______________________________________________
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> > > Speakup@braille.uwo.ca
> > > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
> >
> 
> 
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Re: piping output of dd through bzip2

[Charles Hallenbeck]

The '>' is probably crucial. According to the man page for bzip2,
if no filenames are specified, standard input and standard output
are used. As I read it, that means if you specify an output file
without the redirection symbol, bzip2 no longer accepts standard
input. So if you want to pipe the output of dd directly into
bzip2 you must not give bzip2 any filenames. Redirection of the
bzip2 output is the only way to do that.

The dd man page implies that omitting the of= parameter implies
standard output.


On Mon, 14 Jan 2002, Gregory Nowak wrote:

> Why should I use bzip if bzip2 gives better compression?
> Greg
>
>
> On Mon, Jan 14, 2002 at 03:57:06PM -0700, Jason wrote:
> > try it with 'bzip > windows.img'
> > On Monday January 14, 2002 03:42 pm, you wrote:
> > > Ok, I've just tried the following using the format indicated.
> > >
> > > "dd if=/dev/hda1 |bzip2 -9 windows.img"
> > >
> > > The result was:
> > >
> > > bzip2: Can't open input file windows.img: No such file or directory.
> > > 9+0 records in
> > > 8+0 records out
> > >
> > >
> > > Greg
> > >
> >
> > _______________________________________________
> > Speakup mailing list
> > Speakup@braille.uwo.ca
> > http://speech.braille.uwo.ca/mailman/listinfo/speakup
>
> _______________________________________________
> Speakup mailing list
> Speakup@braille.uwo.ca
> http://speech.braille.uwo.ca/mailman/listinfo/speakup
>

*<<<=-=>>>*<<<=-=>>>*<<<=-=>>>*<<<=-=>>>*
Visit me at http://www.mhonline.net/~chuckh
The Moon is Waxing Crescent (3% of Full)

Re: piping output of dd through bzip2

[Gregory Nowak]

Thanks, that worked.
Greg


On Mon, Jan 14, 2002 at 05:51:35PM -0800, Tyler Spivey wrote:
> this one worked for me in testing:
> dd if=file | bzip2 - >file.bz2
> 
>  .. sig goes here ...
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re: piping output of dd through bzip2

[Tyler Spivey]

this one worked for me in testing:
dd if=file | bzip2 - >file.bz2

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