The "-W|--wide" option?

[Nick Clifton]

Hi Carlos,

> we noticed that some of the
> do_wide checks were not quite accurate.

I am not really that surprised.  We have never been very strict about 
enforcing the 80 character width limit.

> However, without a clear statement about *what* to do with
> long lines, the correct fix is unclear.

Hmm, OK, then how about this:

   When do_wide is *not* enabled and an output line would pass
   the 80th column then it must either be wrapped, truncated
   or abbreviated.

   For preference the output should be abbreviated.  Failing
   that truncation should be used.  If however the output is
   part of a new feature and truncation would likely hinder
   its comprehension then wrapping should be employed.  The
   intention here is that without --wide specified the output
   should be short and concise, not long and wordy.

   If the output is wrapped, then some clear indication
   should be given that wrapping has occurred.  If the output
   is abbreviated then a description of the abbreviation(s)
   used should be included, either in the output or the
   documentation or both.  If the output is truncated then it
   should be possible for a user, under reasonable
   circumstances, to tell that truncation has occurred.

This is off the top of my head, so if you have any suggestions for 
improvement or comments, please feel free to say so.


> To give a concrete example:

>                if (do_wide || strlen ((char *) directory_table[0])<  76)
>                  printf (_("CU: %s/%s:\n"), directory_table[0],
>                          file_table[0].name);

> Say directory_table[0] is 75, the printf is at least 81,
> that's assuming the second %s is null, and it's not likely
> to be null because it's the file name. Therefore this is
> a non-wide printout exceeding 80 columns.


> However, in hindsight it would appear that the choice itself
> is part of the output "ABI" and consumers which previously
> expected a full filename output would then only get the
> short version.
>
> The manual page isn't strictly clear about the default
> behaviour when -W is not in effect.
>
> How strict are we going to be? Must this code remain as-is?

No.  In my opinion this is a bug, and the output should be truncated to 
80 characters.  Consumers that rely upon finding the full filename 
should be invoking readelf with the --wide option enabled.  Failure to 
do this means that they should expect to see truncated filenames.

Essentially the purpose of -W is to prevent truncation, usually of 
filenames or function names.  Tools that use the output from readelf 
must decide if they want full or truncated names and invoke the tool 
appropriately.

Cheers
   Nick