Wireshark · Wireshark-dev: Re: [Wireshark-dev] How to retrieve text displayed for a proto_item ?

[Jaap Keuter <jaap.keuter@xxxxxxxxx>]

On 2011-12-22 15:25, Teto wrote:

> Hi everybody,
>
> Easy question despite I couldn't find the answer. Here is an example 
> -
> not a real one - of what I would like to do:
>
> proto_item* pi = proto_tree_add_text(tree, tvb, offset, 4, "Sub-tlvs
> number" );
> col_add_fstr(cinfo, COL_INFO, "test: %s" ,
> get_displayed_text_of_proto_item(pi) );
>
> It woud ideally display "Sub-tlvs number" in COL_INFO part. So what's
> the equivalent for "get_displayed_text_of_proto_item(pi)". I tried
> with PITEM_FINFO(subtree)->hfinfo->name but seems like the wrong part
> (displayed nthg).
>
> Regards
> Matt

Hi,

This is considered bad style, not recommended, subject to change, etc.

So what you should do is setup your string, like so:

  const char labelstring[] = "Sub-tlvs number";

and use it, like so:

  proto_tree_add_text(tree, tvb, offset, 4, labelstring);
  col_add_fstr(cinfo, COL_INFO, "test: %s", labelstring);

So work out your string in a pointer and use that. If the actual string
depends on a certain variable, Wirehshark provides several kinds of 
nice
translation functions. val_to_str(), using valuestrings. It can be used 
in
header fields too!

But if you must, and there is no guarantee it works in every case (like
display filters yes/no, coloring yes/no, or in tshark), you should look
into finfo, not hfinfo. Note this won't pass the inspection by 
reviewers.

Thanks,
Jaap