Re: Tabbed & pretty output

[Tony Abou-Assaleh]

Jonatan Wallmander wrote:
> |Hi guys!
>
> I downloaded, compiled and tried the latest grep, 2.5.3.
>
> I'd really like this kind of output: (view this mail with fixed-width 
> font please)
>
> ----
> path1/path2/path3/file.ext: foo bar baz fruu muu koo loo boo poo hello
>                            ||koo loo boo poo hello
> ----
>
> But grep goes:
> ----
> ||path1/path2/path3/file.ext: foo bar baz fruu muu koo loo boo poo hello
> ||koo loo boo poo hello
> ----
>
> Which is more difficult to read IMO, it would totally rock to have the 
> first kind of output available..
> It would place more emphasis on the files.
> I guessed the -T parameter would do this, but on my fedora it doesn't 
> work, or did I misunderstand -T ?

From the grep docs:

-T, --initial-tab
  Make sure that the first character of actual line content lies
  on a tab stop, so that the alignment of tabs looks normal.

So it only affects on which column of your terminal the word 'foo' in 
your example would start. Currently, grep doesn't wrap lines for you; it 
is done by your terminal.

> So this is either a bug report or a feature request :)

What you're suggesting is essentially defining some environment variable 
where you specify how many chars to output per line (similar to COLUMNS 
for 'ps') and apply the -T behaviour to wrapped lines. The following 
perl script does something similar to what you suggest (in a very 
primitive way):

--
# Usage: wrap.pl cols grep_output
$cols = shift;
while (<>) {
        /^([^:]*:)(.*)$/;
        $head = $1;
        $tail = $2;
        $head_len = length($head);
        $tail_cols = $cols - $head_len;
        print $head . substr($tail, 0, $tail_cols) . "\n";
        $tail = substr($tail, $tail_cols);
        $head =~ s/./ /g;
        while ($tail ne "") {
                print $head . substr($tail, 0, $tail_cols) . "\n";
                $tail = substr($tail, $tail_cols);
        }

}
--

Use it as:

$ grep -H mypattern *.txt | perl wrap.pl 30

One can probably write a more elegant formatter in awk ;O) This script 
is provided for illustration only; it doesn't do any error checking and 
will not work in all cases.

Cheers,

TAA

--
Tony Abou-Assaleh
Email:    address@hidden
Web site: http://tony.abou-assaleh.net