What's the difference between wrestool and binwalk? - windows

I am doing some analysis on some file in Windows. And I wonder why I can unpack some file by using binwalk. But sometimes I can only use wrestool to unpack it. What's the difference between this two?

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Conversion between knitr and sweave

This might have been asked before, but until now I couldn't find a really helpful answer for me.
I am using R Studio with knitr and a colleague of mine who I need to cooperate with uses the sweave format. Is there a good way to convert a script back and forth between these two?
I have already found "Sweave2knitr" and hoped this would have an .rmd as output with all chunks changed (<<>> to {} etc.) but this is not the case. My main problem is that I would also need the option to convert from .rmd back to .rnw so that my colleague can also re-edit my work-over.
Thanks a lot!
To process the code chunks and convert the .Rnw file to .tex, you use the knit() function in the knitr package rather than Sweave().
R -e 'library(knitr);knit("my_file.Rnw")'
Sweave2knitr() is for converting old Sweave-based .Rnw files to the knitr syntax.
In Program defaults change :
Weave Rnw files using Sweave or knitr
The Rnw format is really LaTeX with some modifications, whereas the Rmd format is Markdown with some modifications. There are two main flavours of Rnw, the one used by Sweave being the original, and the one used by knitr being a modification of it, but they are very similar.
It's not hard to change Sweave flavoured Rnw to knitr flavoured Rnw (that's what Sweave2knitr does), but changing either one to Rmd would require extensive changes, and probably isn't feasible: certainly I'd expect a lot of manual work after the change.
So for your joint work with a co-author, I would recommend that you settle on a single format, and just use that. I would choose Rmd for this: it's much easier for your co-author to learn Markdown than for you to learn LaTeX. (If you already know LaTeX, that might push the choice the other way.)

How do I effectively identify an unknown file format

I want to write a program that parses yum config files. These files look like this:
[google-chrome]
name=google-chrome - 64-bit
baseurl=http://dl.google.com/linux/chrome/rpm/stable/x86_64
enabled=1
gpgcheck=1
gpgkey=https://dl-ssl.google.com/linux/linux_signing_key.pub
This format looks like it is very easy to parse, but I do not want to reinvent the wheel. If there is an existing library that can generically parse this format, I want to use it.
But how to find a library for something you can not name?
The file extension is no help here. The term ".repo" does not yield any general results besieds yum itself.
So, please teach me how to fish:
How do I effectively find the name of a file format that is unknown to me?
Identifying an unknown file format can be a pain.
But you have some options. I will start with a very obvious one.
Ask
Showing other people the format is maybe the best way to find out its name.
Someone will likely recognize it. And if no one does, chances are good that
you have a proprietary file format in front of you.
In case of your yum repository file, I would say it is a plain old INI file.
But let's do some more research on this.
Reverse Engineering
Reverse Engineering maybe your best bet if nobody recognizes your format.
Take the reference implementation and find out what they are using to parse the format.
Luckily, yum is open source. So it is easy to look up.
Let's see, what the yum authors use to parse their repo file:
try:
ini = INIConfig(open(repo.repofile))
except:
return None
https://github.com/rpm-software-management/yum/blob/master/yum/config.py#L1304
Now the import of this function can be found here:
from iniparse import INIConfig
https://github.com/rpm-software-management/yum/blob/master/yum/config.py#L32
This leads us to a library called iniparse (https://pypi.org/project/iniparse/).
So yum uses an INI parser for its config files.
I will show you how to quickly navigate to those kind of code passages
since navigating in somewhat large projects can be intimidating.
I use a tool called ripgrep (https://github.com/BurntSushi/ripgrep).
My initial anchors are usually well known filepaths. In case of yum, I took /etc/yum.repos.d for my initial search:
# assuming you are in the root directory of yum's source code
rg /etc/yum.repos.d yum
yum/config.py
769: reposdir = ListOption(['/etc/yum/repos.d', '/etc/yum.repos.d'])
yum/__init__.py
556: # (typically /etc/yum/repos.d)
This narrows it down to two files. If you go on further with terms like read or parse,
you will quickly find the results you want.
What if you do not have the reference source?
Well, sometimes, you have no access to the source code of a reference implementation. E.g: The reference implementation is closed source.
Try to break the format. Insert some garbage and observe the log files afterwards. If you are lucky, you may find
a helpful error message which might give you hints about the format.
If you feel very brave, you can try to use an actual decompiler as well. This may or may not be illegal and may or may not be a waste of time.
I personally would only do this as a last resort.

Handle single files while extracting tar.gz

I am having a huge .tgz file which is further structured inside like this:
./RandomFoldername1/file1
./RandomFoldername1/file2
./RandomFoldername2/file1
./RandomFoldername2/file2
etc
What I want to do is having each individual file extracted to standard output so that I can pipe it afterwards to another command. While doing this, I also need to get the RandomFoldername name and file name so that I can deal with them properly from within the second command.
Till now the options I have are
to either extract all of the tarball and deal with the structured files that I will be having, which is not an option since the extracted tar doesn't fit into the hard drive
Make a loop that pattern match each file and extract one file at time. This option although that solves the problem, is too slow because the tarball is sweeped each time for only one file.
While searching on how to solve this, I've started to fear that there is no better alternative to this.
Using tar the tool I don't believe you have any other options.
Using a tar library for some language of your choice should allow you to do what you want though as it should let you iterate over the entries in the tarball one-by-one and allow you to extract/pipe/etc. each file one-by-one as necessary.

Ruby: Read single file from tarball

I want to read the contents of a single file from a .tar.gz tarball. The file is in the root of the tarball. Is there some easy way to do this? I was thinking about something like data = Tarball.open('myfile.tar.gz').entry('/myentry').content Is there such a thing?
The problem is that a .tar.gz is not a structured file; it's just a .tar file that has been run through a compression algorithm that knows nothing about tar. So the only way to get data back out of it is to uncompress the whole thing first.
As a less-space-efficient but more time-efficient alternative, you may want to consider exploding the tar file, recompressing each file individually, and then tarring them back up into an (uncompressed) archive. Then extracting individual files is easy using the archive-tar gem, and you can just add a decompression step to recover the originals.
This is a very old question without an answer accepted, so I wonder if it's still actual however, someone might come to it when running into a similar issue. If you know a typical pattern in the file you are looking for, you might be able to use
tar xf yourarchive.tar.gz --wildcards 'yourpattern'
, which would extract only the selected file and then you can use it as you prefer.
Let's say each tarball is expected to have an "app.conf" file then you use this in 'yourpattern'.
I hope this helps?

ELF/DWARF Parser to Out Structure elements

Is there a way to extract the size and address of elements within a structure using an elf file? I am hoping there is a tool available that can do this and export it to a more readable format.
My end goal is to convert the ELF file to a ASAM A2L file. A open source/free tool that could do this would even be better but most companies that do this charge alot for their tools.
I don't know offhand of anything pre-canned, but it isn't very hard to modify an existing tool to do it.
The "pahole" program from the "dwarves" project does something similar. It prints a structure definition in a certain way.
There's also a "pahole.py" script for gdb that does pretty much the same thing. This would be trivial to modify to print things however you like.
If you want to get a little deeper you could write it yourself using one of the existing DWARF libraries. I like the one in elfutils, but YMMV.

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