jlengrand.github.io/_posts/2013-10-26-find-whether-a-windows-dll-is-compiled-for-32-or-64-bits-on-linux.markdown

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layout	status	published	title	author	author_login	author_email	author_url	wordpress_id	wordpress_url	date	categories	tags	comments
post	publish	true	Find whether a Windows dll is compiled for 32 or 64 bits on Linux	Julien Lengrand-Lambert	jlengrand	julien@lengrand.fr	http://www.lengrand.fr	896	http://www.lengrand.fr/?p=896	2013-10-26 16:33:36.000000000 +02:00	misc tips programming	windows linux objdump dll dependency walker

This morning, I stumbled upon an unexpected problem; and found myself not knowing what to do.

I had to compile the native part of a library on Linux, based on the existing Windows dlls. Before compiling, I needed to know if the Windows dlls were compiled for 32 or 64 bits.

It is quite easy to do on Windows, with tools such as dependency walker, but on Linux!?

I knew that for native linux (.so) files, objdump would be my weapon of choice.

So I gave it a shot, and tried:

{% highlight bash %} $ objdump -x my_windows.dll | head -n 15 # returns the first 15 lines of the result

{% endhighlight %}

And here was the result :

{% highlight bash %}

libxuggle-5.dll: file format pei-i386

libxuggle-5.dll

architecture: i386, flags 0x00000133:

HAS_RELOC, EXEC_P, HAS_SYMS, HAS_LOCALS, D_PAGED

start address 0x6e741058

Characteristics 0x2306

executable

line numbers stripped

32 bit words

debugging information removed

DLL

{% endhighlight %}

Pretty neat, huh?

I was really not expecting objdump to be so efficient even on Windows stuff.

Well done, Linux. Well done.