From: salamond <jarodzz@...>
Date: 2012-06-28T12:21:38+09:00
Subject: Re: how about adding method hook

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sorry to robert.

Took me a night to figure out the git code. with method_added and
class_eval.

nice piece of code.

it works too.


On Wed, Jun 27, 2012 at 10:19 PM, salamond <jarodzz@gmail.com> wrote:

> Hi, Henry.
>
> thanks for the info.
>
> method missing might be a good option.
>
> class Process
>   def run; end
> end
>
> class FileUtils
>   def mkdir; end
> end
>
> class Agent
>   def method_missing
>     if Process.new.respond_to(method) || FileUtiles.response_to(method)
>       do_as_me
>          Process.new.send(method)
>       end
>    end
> end
>
> sort of like this. what do you think?
>
>
>
>
> On Wed, Jun 27, 2012 at 6:26 PM, Henry Maddocks <hmaddocks@me.com> wrote:
>
>>
>> On 27/06/2012, at 8:12 PM, salamond <jarodzz@gmail.com> wrote:
>>
>> Hi, guys.
>>
>> I want An agent on machine, so that it can fake user actions.
>>
>> ...
>>
>> My problem is, I have a very long list of actions, like mv, touch, mkdir,
>> rm, etc.
>>  I don't want to add save and restore euid for all methods.
>>
>>
>> First thing I'd do is remove all the duplication, maybe something like
>> this...
>>
>> class Agent
>>   def initialize(user, dir)
>>     @user = user
>>     @dir = dir
>>   end
>>
>>   def as_me_do
>>     bak = Process.euid
>>       yield
>>
>>   ensure # hat tip Robert
>>     Process.euid = bak
>>   end
>>
>>   def mkdir(dir)
>>     as_me_do {`mkdir`}
>>   end
>>
>>   def create_file(file, content)
>>     as_me_do {`echo #{content} > #{file}`}
>>   end
>> end
>>
>> The next step might be more obvious.
>>
>> I kind of guess here I should use some meta programming skills. here's
>> what i tried.
>>
>>
>> Defining methods is going to be tricky, because you don't have consistent
>> method signatures and system calls. Maybe a have a hash of methods =>
>> system calls and method missing?
>>
>> Also, why back ticks, why not use ruby File methods?
>>
>> Henry
>>
>>
>

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sorry to robert.<div><br></div><div>Took me a night to figure out the git c=
ode. with method_added and class_eval.</div><div><br></div><div>nice piece =
of code.</div><div><br></div><div>it works too.</div><div><br><br><div clas=
s=3D"gmail_quote">
On Wed, Jun 27, 2012 at 10:19 PM, salamond <span dir=3D"ltr">&lt;<a href=3D=
"mailto:jarodzz@gmail.com" target=3D"_blank">jarodzz@gmail.com</a>&gt;</spa=
n> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;b=
order-left:1px #ccc solid;padding-left:1ex">
<div class=3D"im">Hi, Henry.<div><br></div><div>thanks for the info.</div><=
div><br></div><div>method missing might be a good option.</div><div><br></d=
iv><div>class Process</div><div>=A0 def run; end</div><div>end</div><div><b=
r>
</div><div>class FileUtils</div>
<div>=A0 def mkdir; end</div><div>end</div><div><br></div><div>class Agent<=
/div><div>=A0 def method_missing</div><div>=A0 =A0 if Process.new.respond_t=
o(method) || FileUtiles.response_to(method)</div><div>=A0 =A0 =A0 do_as_me<=
/div><div>

=A0 =A0 =A0 =A0 =A0Process.new.send(method)</div><div>=A0 =A0 =A0 end</div>=
<div>=A0 =A0end</div><div>end</div><div><br></div><div>sort of like this. w=
hat do you think?</div><div><br></div><div><br></div></div><div><br><br><di=
v class=3D"gmail_quote">
<div class=3D"im">
On Wed, Jun 27, 2012 at 6:26 PM, Henry Maddocks <span dir=3D"ltr">&lt;<a hr=
ef=3D"mailto:hmaddocks@me.com" target=3D"_blank">hmaddocks@me.com</a>&gt;</=
span> wrote:<br></div><div><div class=3D"h5"><blockquote class=3D"gmail_quo=
te" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"=
>

<div bgcolor=3D"#FFFFFF"><div><div><br></div><div>On 27/06/2012, at 8:12 PM=
, salamond &lt;<a href=3D"mailto:jarodzz@gmail.com" target=3D"_blank">jarod=
zz@gmail.com</a>&gt; wrote:<br><br></div><div></div></div><blockquote type=
=3D"cite">

<div><div>Hi, guys.<div><br></div><div>I want An agent on machine, so that =
it can fake user actions.</div><div><br></div></div><div>...</div><div><div=
><br></div><div>My problem is, I have a very long list of actions, like mv,=
 touch, mkdir, rm, etc.</div>

<div>
I don&#39;t want to add save and restore euid for all methods.</div></div><=
/div></blockquote><div><br></div><div>First thing I&#39;d do is remove all =
the duplication, maybe something like this...</div><div><br></div><span><di=
v>

<div>class Agent</div><div>=A0 def initialize(user, dir)</div><div>=A0 =A0 =
@user =3D user</div><div>=A0 =A0 @dir =3D dir</div><div>=A0 end</div><div><=
br></div></div><div>=A0 def as_me_do</div><div>=A0 =A0 bak =3D Process.euid=
</div><div>=A0 =A0 =A0 yield</div>

<div><br></div><div>=A0 ensure # hat tip Robert</div><div>=A0 =A0 Process.e=
uid =3D bak</div><div>=A0 end</div><div><br></div><div>=A0 def mkdir(dir)</=
div><div>=A0 =A0 as_me_do {<span>`mkdir`}</span></div><div>=A0 end</div><di=
v><br></div><div>

=A0 def create_file(file, content)</div><div>=A0 =A0 as_me_do {<span>`echo =
#{content} &gt; #{file}`}</span></div><div>=A0 end</div><div>end</div></spa=
n><div><br></div><div>The next step might be more obvious.</div><br><blockq=
uote type=3D"cite">

<div><div>I kind of guess here I should use some meta programming skills. h=
ere&#39;s what i tried.</div>
</div></blockquote><br><div>Defining methods is going to be tricky, because=
 you don&#39;t have consistent method signatures and system calls. Maybe a =
have a hash of methods =3D&gt; system calls and method missing?</div><div>

<br></div><div>Also, why back ticks, why not use ruby File methods?</div><s=
pan><font color=3D"#888888"><div><br></div><div>Henry</div><div><br></div><=
/font></span></div></blockquote></div></div></div><br></div>
</blockquote></div><br></div>

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