Re: readelf --string-dump analog for objdump

[Maxim Dementyev <mdementyev@fluendo.com>]

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Dear Jan,

Thanks for pointing me out the objdump utility!
Unfortunately, --only-section isn't a good choice: it produces all other
information in the output file, not only the section in question.
But I've found the need option of objdump utility: --dump-section
Unfortunately, apart from this, again, the objdump utility creates a
formatted file as an output, and I can add --only-section to reduce the
size of it and redirect it to /dev/null.

So, this is usable with one intermediate file for a section.
But it is much more complicated than just:
"readelf -p section file | grep something".

And a possible solution (how to improve the objdump utility in a generic
way) could be a special value for the --dump-section option to produce the
output only for this section instead of redirecting it to a separate file:
"objcopy --dump-section section=stdout | grep something"

Thanks again!

With respect,
Max



On Mon, Jan 22, 2024 at 11:58 AM Jan Beulich <jbeulich@suse.com> wrote:

> On 22.01.2024 11:43, Maxim Dementyev wrote:
> > The readelf utility has a very useful option - "--string-dump=<number or
> > name>" which displays the contents of the indicated section as is (as
> > printable strings).
> > As far as I can understand, to do the same with the objdump you need to
> do
> > "objdump --section=<number or name> --full-contents ...".
> > But the output is in the "hexdump" format, the contents is splitted by
> 0x10
> > size blocks (so, not possible to grep on this contents).
> >
> > Is there any plans to implement a printable strings format for this case
> > for the objdump utility?
> > Or is there a solution without parsing the hexdump format and restoring
> > these printable strings?
>
> From what you write I can only guess that you'd like to use the
> functionality
> on non-ELF objects which binutils as whole (and maybe objdump in
> particular)
> supports. If so, is there a reason you can't extract the section(s) in
> question using "objcopy --only-section" (e.g. as a raw binary file), and
> then
> use "strings" on the result?
>
> Jan
>

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