@7hir7een: You can basically put it anywhere, as long as you call that one, and not USBNet's.
I usually put those kind of testing things in root's $HOME, since it's a tmpfs, but in this specific case, replacing USBNet's binary is a good idea, since that one is mostly broken on the KOA2 anyway

. And then you can just call "strace" since USBNet's one is in your PATH

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EDIT: Just to be perfectly clear: you did get to see that string printed on your screen, right? ^^. That'd be a good news, since KOReader should mostly do the same thing...
EDITē: Err, of course, you have to unpack the tarball, first

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tar xvzf strace-koa2.tar.gz 
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