Re: [RFC] A new command 'grep'

[Abhijit Halder <abhijit.k.halder@gmail.com>]

On Mon, Jan 2, 2012 at 2:58 PM, Kevin Pouget <kevin.pouget@gmail.com> wrote:
> On Mon, Jan 2, 2012 at 9:54 AM, Eli Zaretskii <eliz@gnu.org> wrote:
>>
>> I think this is the first time we receive a proposal for a command
>> implemented in Python.  Perhaps there's a place to discuss whether
>> some policy is in order in this regard.  E.g., the command will be
>> unavailable in non-Python builds, which at least needs to be
>> documented.  There may be other aspects that are worth discussing.
>
> I'm also curious about that, and maybe first of all, is there a Python
> specific coding convention likely to be enforced in GNU projects
> and/or GDB?
>
>>> Date: Mon, 2 Jan 2012 10:30:55 +0530
>>> From: Siva Chandra <sivachandra@google.com>
>>>
>>> Attached is a patch which implements a 'grep' command using the GDB
>>> Python API. The idea behind the 'grep' command is as follows. We often
>>> have deep data structures and are probably interested in some one
>>> particular field or value embedded somewhere deep in that data
>>> structure. For such cases, instead of typing the complete expression
>>> for the field, we can use the 'grep' command to lookup the field or
>>> value of interest.
>>
>> Thanks.
>>
>> I think this is the first time we receive a proposal for a command
>> implemented in Python.  Perhaps there's a place to discuss whether
>> some policy is in order in this regard.  E.g., the command will be
>> unavailable in non-Python builds, which at least needs to be
>> documented.  There may be other aspects that are worth discussing.
>>
>> If this is accepted, it will need user-level documentation.
>>
>> I cannot say I like the name "grep".  Users will associate that name
>> with the Unix command that searches through files, which is radically
>> different from what your command does.  How about "lookup-fields"
>> instead?
>
> There was a discussion a few months ago about "Implementation of pipe
> to pass GDB's command output to the shell" [1] which would allow to
> use the 'real' grep to do a similar job, but I'm not sure about the
> status of this patch, it seems not to be in the trunk yet, according
> to the ChangeLog.

Hi all,

Sorry, I'm still struggling with copyright assignment. I almost got
approval from my organization but waiting for the disclaimer to be in
hand. I will send a final patch for review once this assignment is
done.

Thanks,
Abhijit Halder

>
> I didn't really look in depth at the sources, but based on you email
> description, I wonder how it differs from a generic code like that
> (not tested):
>
>> (gdb) grep int ss
>> ss.int_val = (int) 10
>
> #assume set print pretty on
>
> command = "print %s" % ss
> to_grep = "int"
>
> out = gdb.execute (command, to_string=True)
> for line in out.split("\n")
>  if to_grep in line:
>    print line
>
>
> good idea anyway,
> thanks,
>
> Kevin
>
> [1]: http://sourceware.org/ml/gdb-patches/2011-08/msg00483.html